test(snapshot): migrate snapshot tests to Effect runner (#26964)

packages/opencode/test/snapshot/snapshot.test.ts

@@ -1,13 +1,15 @@
-import { afterEach, test, expect } from "bun:test"
+import { afterEach, expect } from "bun:test"
 import { $ } from "bun"
+import { CrossSpawnSpawner } from "@opencode-ai/core/cross-spawn-spawner"
 import fs from "fs/promises"
 import path from "path"
-import { Effect } from "effect"
+import { Effect, Fiber } from "effect"
 import { Snapshot } from "../../src/snapshot"
-import { Instance } from "../../src/project/instance"
-import { WithInstance } from "../../src/project/with-instance"
 import { Filesystem } from "@/util/filesystem"
-import { disposeAllInstances, provideInstance, tmpdir } from "../fixture/fixture"
+import { disposeAllInstances, provideInstance, TestInstance, tmpdirScoped } from "../fixture/fixture"
+import { testEffect } from "../lib/effect"
+
+const it = testEffect(Snapshot.defaultLayer)
 
 // Git always outputs /-separated paths internally. Snapshot.patch() joins them
 // with path.join (which produces \ on Windows) then normalizes back to /.
@@ -18,1515 +20,1099 @@ afterEach(async () => {
   await disposeAllInstances()
 })
 
-async function bootstrap() {
-  return tmpdir({
-    git: true,
-    init: async (dir) => {
-      const unique = Math.random().toString(36).slice(2)
-      const aContent = `A${unique}`
-      const bContent = `B${unique}`
-      await Filesystem.write(`${dir}/a.txt`, aContent)
-      await Filesystem.write(`${dir}/b.txt`, bContent)
-      await $`git add .`.cwd(dir).quiet()
-      await $`git commit -m init`.cwd(dir).quiet()
-      return {
-        aContent,
-        bContent,
-      }
-    },
+const exec = (cwd: string, command: string[]) =>
+  Effect.promise(async () => {
+    const proc = Bun.spawn(command, { cwd, stdout: "ignore", stderr: "pipe" })
+    const code = await proc.exited
+    if (code !== 0) throw new Error(`${command.join(" ")} failed: ${await new Response(proc.stderr).text()}`)
   })
-}
 
-function run<A>(dir: string, body: (snapshot: Snapshot.Interface) => Effect.Effect<A>) {
-  return Effect.runPromise(
-    Effect.gen(function* () {
-      const snapshot = yield* Snapshot.Service
-      return yield* body(snapshot)
-    }).pipe(provideInstance(dir), Effect.provide(Snapshot.defaultLayer)),
+const write = (file: string, content: string | Uint8Array) => Effect.promise(() => Filesystem.write(file, content))
+const readText = (file: string) => Effect.promise(() => fs.readFile(file, "utf-8"))
+const exists = (file: string) =>
+  Effect.promise(() =>
+    fs
+      .access(file)
+      .then(() => true)
+      .catch(() => false),
   )
-}
-
-test("tracks deleted files correctly", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      const before = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(before).toBeTruthy()
-
-      await $`rm ${tmp.path}/a.txt`.quiet()
-
-      expect((await run(tmp.path, (snapshot) => snapshot.patch(before!))).files).toContain(fwd(tmp.path, "a.txt"))
-    },
-  })
+const mkdirp = (dir: string) => Effect.promise(() => fs.mkdir(dir, { recursive: true }))
+const rm = (file: string) => Effect.promise(() => fs.rm(file, { recursive: true, force: true }))
+
+const initialize = Effect.fn("SnapshotTest.initialize")(function* (dir: string) {
+  const unique = Math.random().toString(36).slice(2)
+  const aContent = `A${unique}`
+  const bContent = `B${unique}`
+  yield* write(`${dir}/a.txt`, aContent)
+  yield* write(`${dir}/b.txt`, bContent)
+  yield* exec(dir, ["git", "add", "."])
+  yield* exec(dir, ["git", "commit", "-m", "init"])
+  return { aContent, bContent }
 })
 
-test("revert should remove new files", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      const before = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(before).toBeTruthy()
-
-      await Filesystem.write(`${tmp.path}/new.txt`, "NEW")
-
-      const patch = await run(tmp.path, (snapshot) => snapshot.patch(before!))
+type Bootstrapped = { path: string; extra: { aContent: string; bContent: string } }
 
-      await run(tmp.path, (snapshot) => snapshot.revert([patch]))
-
-      expect(
-        await fs
-          .access(`${tmp.path}/new.txt`)
-          .then(() => true)
-          .catch(() => false),
-      ).toBe(false)
-    },
-  })
+const bootstrap = Effect.fn("SnapshotTest.bootstrap")(function* () {
+  const tmp = yield* TestInstance
+  return { path: tmp.directory, extra: yield* initialize(tmp.directory) }
 })
 
-test("revert in subdirectory", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      const before = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(before).toBeTruthy()
-
-      await $`mkdir -p ${tmp.path}/sub`.quiet()
-      await Filesystem.write(`${tmp.path}/sub/file.txt`, "SUB")
-
-      const patch = await run(tmp.path, (snapshot) => snapshot.patch(before!))
-
-      await run(tmp.path, (snapshot) => snapshot.revert([patch]))
-
-      expect(
-        await fs
-          .access(`${tmp.path}/sub/file.txt`)
-          .then(() => true)
-          .catch(() => false),
-      ).toBe(false)
-      // Note: revert currently only removes files, not directories
-      // The empty subdirectory will remain
-    },
+const withTrackedSnapshot = <A, E, R>(
+  fn: (input: { tmp: Bootstrapped; snapshot: Snapshot.Interface; before: string }) => Effect.Effect<A, E, R>,
+) =>
+  Effect.gen(function* () {
+    const tmp = yield* bootstrap()
+    const snapshot = yield* Snapshot.Service
+    const before = yield* snapshot.track()
+    expect(before).toBeTruthy()
+    return yield* fn({ tmp, snapshot, before: before! })
   })
-})
-
-test("multiple file operations", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      const before = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(before).toBeTruthy()
 
-      await $`rm ${tmp.path}/a.txt`.quiet()
-      await Filesystem.write(`${tmp.path}/c.txt`, "C")
-      await $`mkdir -p ${tmp.path}/dir`.quiet()
-      await Filesystem.write(`${tmp.path}/dir/d.txt`, "D")
-      await Filesystem.write(`${tmp.path}/b.txt`, "MODIFIED")
-
-      const patch = await run(tmp.path, (snapshot) => snapshot.patch(before!))
-
-      await run(tmp.path, (snapshot) => snapshot.revert([patch]))
-
-      expect(await fs.readFile(`${tmp.path}/a.txt`, "utf-8")).toBe(tmp.extra.aContent)
-      expect(
-        await fs
-          .access(`${tmp.path}/c.txt`)
-          .then(() => true)
-          .catch(() => false),
-      ).toBe(false)
-      // Note: revert currently only removes files, not directories
-      // The empty directory will remain
-      expect(await fs.readFile(`${tmp.path}/b.txt`, "utf-8")).toBe(tmp.extra.bContent)
-    },
-  })
+const bootstrapScoped = Effect.fn("SnapshotTest.bootstrapScoped")(function* () {
+  const dir = yield* tmpdirScoped({ git: true }).pipe(Effect.provide(CrossSpawnSpawner.defaultLayer))
+  return { path: dir, extra: yield* initialize(dir) }
 })
 
-test("empty directory handling", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      const before = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(before).toBeTruthy()
-
-      await $`mkdir ${tmp.path}/empty`.quiet()
+const scopedGitTmpdir = () => tmpdirScoped({ git: true }).pipe(Effect.provide(CrossSpawnSpawner.defaultLayer))
 
-      expect((await run(tmp.path, (snapshot) => snapshot.patch(before!))).files.length).toBe(0)
-    },
+const cleanupWorktree = (repo: string, worktree: string, files: string[] = []) =>
+  Effect.promise(async () => {
+    await $`git worktree remove --force ${worktree}`.cwd(repo).quiet().nothrow()
+    await fs.rm(worktree, { recursive: true, force: true }).catch(() => undefined)
+    await Promise.all(files.map((file) => fs.rm(file, { recursive: true, force: true }).catch(() => undefined)))
   })
-})
-
-test("binary file handling", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      const before = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(before).toBeTruthy()
 
-      await Filesystem.write(`${tmp.path}/image.png`, new Uint8Array([0x89, 0x50, 0x4e, 0x47]))
+const withGitConfigGlobal = <A, E, R>(config: string, self: Effect.Effect<A, E, R>) =>
+  Effect.acquireUseRelease(
+    Effect.sync(() => {
+      const previous = process.env.GIT_CONFIG_GLOBAL
+      process.env.GIT_CONFIG_GLOBAL = config
+      return previous
+    }),
+    () => self,
+    (previous) =>
+      Effect.sync(() => {
+        if (previous) process.env.GIT_CONFIG_GLOBAL = previous
+        else delete process.env.GIT_CONFIG_GLOBAL
+      }),
+  )
 
-      const patch = await run(tmp.path, (snapshot) => snapshot.patch(before!))
+it.instance(
+  "tracks deleted files correctly",
+  withTrackedSnapshot(({ tmp, snapshot, before }) =>
+    Effect.gen(function* () {
+      yield* rm(`${tmp.path}/a.txt`)
+      expect((yield* snapshot.patch(before)).files).toContain(fwd(tmp.path, "a.txt"))
+    }),
+  ),
+  { git: true },
+)
+
+it.instance(
+  "revert should remove new files",
+  withTrackedSnapshot(({ tmp, snapshot, before }) =>
+    Effect.gen(function* () {
+      yield* write(`${tmp.path}/new.txt`, "NEW")
+      const patch = yield* snapshot.patch(before)
+      yield* snapshot.revert([patch])
+      expect(yield* exists(`${tmp.path}/new.txt`)).toBe(false)
+    }),
+  ),
+  { git: true },
+)
+
+it.instance(
+  "revert in subdirectory",
+  withTrackedSnapshot(({ tmp, snapshot, before }) =>
+    Effect.gen(function* () {
+      yield* mkdirp(`${tmp.path}/sub`)
+      yield* write(`${tmp.path}/sub/file.txt`, "SUB")
+      const patch = yield* snapshot.patch(before)
+      yield* snapshot.revert([patch])
+      expect(yield* exists(`${tmp.path}/sub/file.txt`)).toBe(false)
+    }),
+  ),
+  { git: true },
+)
+
+it.instance(
+  "multiple file operations",
+  withTrackedSnapshot(({ tmp, snapshot, before }) =>
+    Effect.gen(function* () {
+      yield* rm(`${tmp.path}/a.txt`)
+      yield* write(`${tmp.path}/c.txt`, "C")
+      yield* mkdirp(`${tmp.path}/dir`)
+      yield* write(`${tmp.path}/dir/d.txt`, "D")
+      yield* write(`${tmp.path}/b.txt`, "MODIFIED")
+      const patch = yield* snapshot.patch(before)
+      yield* snapshot.revert([patch])
+      expect(yield* readText(`${tmp.path}/a.txt`)).toBe(tmp.extra.aContent)
+      expect(yield* exists(`${tmp.path}/c.txt`)).toBe(false)
+      expect(yield* readText(`${tmp.path}/b.txt`)).toBe(tmp.extra.bContent)
+    }),
+  ),
+  { git: true },
+)
+
+it.instance(
+  "empty directory handling",
+  withTrackedSnapshot(({ tmp, snapshot, before }) =>
+    Effect.gen(function* () {
+      yield* mkdirp(`${tmp.path}/empty`)
+      expect((yield* snapshot.patch(before)).files.length).toBe(0)
+    }),
+  ),
+  { git: true },
+)
+
+it.instance(
+  "binary file handling",
+  withTrackedSnapshot(({ tmp, snapshot, before }) =>
+    Effect.gen(function* () {
+      yield* write(`${tmp.path}/image.png`, new Uint8Array([0x89, 0x50, 0x4e, 0x47]))
+      const patch = yield* snapshot.patch(before)
       expect(patch.files).toContain(fwd(tmp.path, "image.png"))
-
-      await run(tmp.path, (snapshot) => snapshot.revert([patch]))
-      expect(
-        await fs
-          .access(`${tmp.path}/image.png`)
-          .then(() => true)
-          .catch(() => false),
-      ).toBe(false)
-    },
-  })
-})
-
-test("symlink handling", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      const before = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(before).toBeTruthy()
-
-      await fs.symlink(`${tmp.path}/a.txt`, `${tmp.path}/link.txt`, "file")
-
-      expect((await run(tmp.path, (snapshot) => snapshot.patch(before!))).files).toContain(fwd(tmp.path, "link.txt"))
-    },
-  })
-})
-
-test("file under size limit handling", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      const before = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(before).toBeTruthy()
-
-      await Filesystem.write(`${tmp.path}/large.txt`, "x".repeat(1024 * 1024))
-
-      expect((await run(tmp.path, (snapshot) => snapshot.patch(before!))).files).toContain(fwd(tmp.path, "large.txt"))
-    },
-  })
-})
-
-test("large added files are skipped", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      const before = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(before).toBeTruthy()
-
-      await Filesystem.write(`${tmp.path}/huge.txt`, new Uint8Array(2 * 1024 * 1024 + 1))
-
-      expect((await run(tmp.path, (snapshot) => snapshot.patch(before!))).files).toEqual([])
-      expect(await run(tmp.path, (snapshot) => snapshot.diff(before!))).toBe("")
-      expect(await run(tmp.path, (snapshot) => snapshot.track())).toBe(before)
-    },
-  })
-})
-
-test("nested directory revert", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      const before = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(before).toBeTruthy()
-
-      await $`mkdir -p ${tmp.path}/level1/level2/level3`.quiet()
-      await Filesystem.write(`${tmp.path}/level1/level2/level3/deep.txt`, "DEEP")
-
-      const patch = await run(tmp.path, (snapshot) => snapshot.patch(before!))
-
-      await run(tmp.path, (snapshot) => snapshot.revert([patch]))
-
-      expect(
-        await fs
-          .access(`${tmp.path}/level1/level2/level3/deep.txt`)
-          .then(() => true)
-          .catch(() => false),
-      ).toBe(false)
-    },
-  })
-})
-
-test("special characters in filenames", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      const before = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(before).toBeTruthy()
-
-      await Filesystem.write(`${tmp.path}/file with spaces.txt`, "SPACES")
-      await Filesystem.write(`${tmp.path}/file-with-dashes.txt`, "DASHES")
-      await Filesystem.write(`${tmp.path}/file_with_underscores.txt`, "UNDERSCORES")
-
-      const files = (await run(tmp.path, (snapshot) => snapshot.patch(before!))).files
+      yield* snapshot.revert([patch])
+      expect(yield* exists(`${tmp.path}/image.png`)).toBe(false)
+    }),
+  ),
+  { git: true },
+)
+
+it.instance(
+  "symlink handling",
+  withTrackedSnapshot(({ tmp, snapshot, before }) =>
+    Effect.gen(function* () {
+      yield* Effect.promise(() => fs.symlink(`${tmp.path}/a.txt`, `${tmp.path}/link.txt`, "file"))
+      expect((yield* snapshot.patch(before)).files).toContain(fwd(tmp.path, "link.txt"))
+    }),
+  ),
+  { git: true },
+)
+
+it.instance(
+  "file under size limit handling",
+  withTrackedSnapshot(({ tmp, snapshot, before }) =>
+    Effect.gen(function* () {
+      yield* write(`${tmp.path}/large.txt`, "x".repeat(1024 * 1024))
+      expect((yield* snapshot.patch(before)).files).toContain(fwd(tmp.path, "large.txt"))
+    }),
+  ),
+  { git: true },
+)
+
+it.instance(
+  "large added files are skipped",
+  withTrackedSnapshot(({ tmp, snapshot, before }) =>
+    Effect.gen(function* () {
+      yield* write(`${tmp.path}/huge.txt`, new Uint8Array(2 * 1024 * 1024 + 1))
+      expect((yield* snapshot.patch(before)).files).toEqual([])
+      expect(yield* snapshot.diff(before)).toBe("")
+      expect(yield* snapshot.track()).toBe(before)
+    }),
+  ),
+  { git: true },
+)
+
+it.instance(
+  "nested directory revert",
+  withTrackedSnapshot(({ tmp, snapshot, before }) =>
+    Effect.gen(function* () {
+      yield* mkdirp(`${tmp.path}/level1/level2/level3`)
+      yield* write(`${tmp.path}/level1/level2/level3/deep.txt`, "DEEP")
+      const patch = yield* snapshot.patch(before)
+      yield* snapshot.revert([patch])
+      expect(yield* exists(`${tmp.path}/level1/level2/level3/deep.txt`)).toBe(false)
+    }),
+  ),
+  { git: true },
+)
+
+it.instance(
+  "special characters in filenames",
+  withTrackedSnapshot(({ tmp, snapshot, before }) =>
+    Effect.gen(function* () {
+      yield* write(`${tmp.path}/file with spaces.txt`, "SPACES")
+      yield* write(`${tmp.path}/file-with-dashes.txt`, "DASHES")
+      yield* write(`${tmp.path}/file_with_underscores.txt`, "UNDERSCORES")
+      const files = (yield* snapshot.patch(before)).files
       expect(files).toContain(fwd(tmp.path, "file with spaces.txt"))
       expect(files).toContain(fwd(tmp.path, "file-with-dashes.txt"))
       expect(files).toContain(fwd(tmp.path, "file_with_underscores.txt"))
-    },
-  })
-})
-
-test("revert with empty patches", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      // Should not crash with empty patches
-      expect(run(tmp.path, (snapshot) => snapshot.revert([]))).resolves.toBeUndefined()
-
-      // Should not crash with patches that have empty file lists
-      expect(run(tmp.path, (snapshot) => snapshot.revert([{ hash: "dummy", files: [] }]))).resolves.toBeUndefined()
-    },
-  })
-})
-
-test("patch with invalid hash", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      const before = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(before).toBeTruthy()
-
-      // Create a change
-      await Filesystem.write(`${tmp.path}/test.txt`, "TEST")
-
-      // Try to patch with invalid hash - should handle gracefully
-      const patch = await run(tmp.path, (snapshot) => snapshot.patch("invalid-hash-12345"))
+    }),
+  ),
+  { git: true },
+)
+
+it.instance(
+  "revert with empty patches",
+  Effect.gen(function* () {
+    yield* bootstrap()
+    const snapshot = yield* Snapshot.Service
+    yield* snapshot.revert([])
+    yield* snapshot.revert([{ hash: "dummy", files: [] }])
+  }),
+  { git: true },
+)
+
+it.instance(
+  "patch with invalid hash",
+  withTrackedSnapshot(({ tmp, snapshot }) =>
+    Effect.gen(function* () {
+      yield* write(`${tmp.path}/test.txt`, "TEST")
+      const patch = yield* snapshot.patch("invalid-hash-12345")
       expect(patch.files).toEqual([])
       expect(patch.hash).toBe("invalid-hash-12345")
-    },
-  })
-})
-
-test("revert non-existent file", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      const before = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(before).toBeTruthy()
-
-      // Try to revert a file that doesn't exist in the snapshot
-      // This should not crash
-      expect(
-        run(tmp.path, (snapshot) =>
-          snapshot.revert([
-            {
-              hash: before!,
-              files: [`${tmp.path}/nonexistent.txt`],
-            },
-          ]),
-        ),
-      ).resolves.toBeUndefined()
-    },
-  })
-})
-
-test("unicode filenames", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      const before = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(before).toBeTruthy()
-
+    }),
+  ),
+  { git: true },
+)
+
+it.instance(
+  "revert non-existent file",
+  withTrackedSnapshot(({ tmp, snapshot, before }) =>
+    Effect.gen(function* () {
+      yield* snapshot.revert([{ hash: before, files: [`${tmp.path}/nonexistent.txt`] }])
+    }),
+  ),
+  { git: true },
+)
+
+it.instance(
+  "unicode filenames",
+  withTrackedSnapshot(({ tmp, snapshot, before }) =>
+    Effect.gen(function* () {
       const unicodeFiles = [
         { path: fwd(tmp.path, "文件.txt"), content: "chinese content" },
         { path: fwd(tmp.path, "🚀rocket.txt"), content: "emoji content" },
         { path: fwd(tmp.path, "café.txt"), content: "accented content" },
         { path: fwd(tmp.path, "файл.txt"), content: "cyrillic content" },
       ]
-
-      for (const file of unicodeFiles) {
-        await Filesystem.write(file.path, file.content)
-      }
-
-      const patch = await run(tmp.path, (snapshot) => snapshot.patch(before!))
+      yield* Effect.all(
+        unicodeFiles.map((file) => write(file.path, file.content)),
+        { concurrency: "unbounded" },
+      )
+      const patch = yield* snapshot.patch(before)
       expect(patch.files.length).toBe(4)
-
-      for (const file of unicodeFiles) {
-        expect(patch.files).toContain(file.path)
-      }
-
-      await run(tmp.path, (snapshot) => snapshot.revert([patch]))
-
-      for (const file of unicodeFiles) {
-        expect(
-          await fs
-            .access(file.path)
-            .then(() => true)
-            .catch(() => false),
-        ).toBe(false)
-      }
-    },
-  })
-})
-
-test.skip("unicode filenames modification and restore", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      const chineseFile = fwd(tmp.path, "文件.txt")
-      const cyrillicFile = fwd(tmp.path, "файл.txt")
-
-      await Filesystem.write(chineseFile, "original chinese")
-      await Filesystem.write(cyrillicFile, "original cyrillic")
-
-      const before = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(before).toBeTruthy()
-
-      await Filesystem.write(chineseFile, "modified chinese")
-      await Filesystem.write(cyrillicFile, "modified cyrillic")
-
-      const patch = await run(tmp.path, (snapshot) => snapshot.patch(before!))
-      expect(patch.files).toContain(chineseFile)
-      expect(patch.files).toContain(cyrillicFile)
-
-      await run(tmp.path, (snapshot) => snapshot.revert([patch]))
-
-      expect(await fs.readFile(chineseFile, "utf-8")).toBe("original chinese")
-      expect(await fs.readFile(cyrillicFile, "utf-8")).toBe("original cyrillic")
-    },
-  })
-})
-
-test("unicode filenames in subdirectories", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      const before = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(before).toBeTruthy()
-
-      await $`mkdir -p "${tmp.path}/目录/подкаталог"`.quiet()
+      for (const file of unicodeFiles) expect(patch.files).toContain(file.path)
+      yield* snapshot.revert([patch])
+      for (const file of unicodeFiles) expect(yield* exists(file.path)).toBe(false)
+    }),
+  ),
+  { git: true },
+)
+
+it.instance.skip(
+  "unicode filenames modification and restore",
+  Effect.gen(function* () {
+    const tmp = yield* bootstrap()
+    const snapshot = yield* Snapshot.Service
+    const chineseFile = fwd(tmp.path, "文件.txt")
+    const cyrillicFile = fwd(tmp.path, "файл.txt")
+    yield* write(chineseFile, "original chinese")
+    yield* write(cyrillicFile, "original cyrillic")
+    const before = yield* snapshot.track()
+    expect(before).toBeTruthy()
+    yield* write(chineseFile, "modified chinese")
+    yield* write(cyrillicFile, "modified cyrillic")
+    const patch = yield* snapshot.patch(before!)
+    expect(patch.files).toContain(chineseFile)
+    expect(patch.files).toContain(cyrillicFile)
+    yield* snapshot.revert([patch])
+    expect(yield* readText(chineseFile)).toBe("original chinese")
+    expect(yield* readText(cyrillicFile)).toBe("original cyrillic")
+  }),
+  { git: true },
+)
+
+it.instance(
+  "unicode filenames in subdirectories",
+  withTrackedSnapshot(({ tmp, snapshot, before }) =>
+    Effect.gen(function* () {
+      yield* mkdirp(`${tmp.path}/目录/подкаталог`)
       const deepFile = fwd(tmp.path, "目录", "подкаталог", "文件.txt")
-      await Filesystem.write(deepFile, "deep unicode content")
-
-      const patch = await run(tmp.path, (snapshot) => snapshot.patch(before!))
+      yield* write(deepFile, "deep unicode content")
+      const patch = yield* snapshot.patch(before)
       expect(patch.files).toContain(deepFile)
-
-      await run(tmp.path, (snapshot) => snapshot.revert([patch]))
-      expect(
-        await fs
-          .access(deepFile)
-          .then(() => true)
-          .catch(() => false),
-      ).toBe(false)
-    },
-  })
-})
-
-test("very long filenames", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      const before = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(before).toBeTruthy()
-
-      const longName = "a".repeat(200) + ".txt"
-      const longFile = fwd(tmp.path, longName)
-
-      await Filesystem.write(longFile, "long filename content")
-
-      const patch = await run(tmp.path, (snapshot) => snapshot.patch(before!))
+      yield* snapshot.revert([patch])
+      expect(yield* exists(deepFile)).toBe(false)
+    }),
+  ),
+  { git: true },
+)
+
+it.instance(
+  "very long filenames",
+  withTrackedSnapshot(({ tmp, snapshot, before }) =>
+    Effect.gen(function* () {
+      const longFile = fwd(tmp.path, `${"a".repeat(200)}.txt`)
+      yield* write(longFile, "long filename content")
+      const patch = yield* snapshot.patch(before)
       expect(patch.files).toContain(longFile)
-
-      await run(tmp.path, (snapshot) => snapshot.revert([patch]))
-      expect(
-        await fs
-          .access(longFile)
-          .then(() => true)
-          .catch(() => false),
-      ).toBe(false)
-    },
-  })
-})
-
-test("hidden files", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      const before = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(before).toBeTruthy()
-
-      await Filesystem.write(`${tmp.path}/.hidden`, "hidden content")
-      await Filesystem.write(`${tmp.path}/.gitignore`, "*.log")
-      await Filesystem.write(`${tmp.path}/.config`, "config content")
-
-      const patch = await run(tmp.path, (snapshot) => snapshot.patch(before!))
+      yield* snapshot.revert([patch])
+      expect(yield* exists(longFile)).toBe(false)
+    }),
+  ),
+  { git: true },
+)
+
+it.instance(
+  "hidden files",
+  withTrackedSnapshot(({ tmp, snapshot, before }) =>
+    Effect.gen(function* () {
+      yield* write(`${tmp.path}/.hidden`, "hidden content")
+      yield* write(`${tmp.path}/.gitignore`, "*.log")
+      yield* write(`${tmp.path}/.config`, "config content")
+      const patch = yield* snapshot.patch(before)
       expect(patch.files).toContain(fwd(tmp.path, ".hidden"))
       expect(patch.files).toContain(fwd(tmp.path, ".gitignore"))
       expect(patch.files).toContain(fwd(tmp.path, ".config"))
-    },
-  })
-})
-
-test("nested symlinks", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      const before = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(before).toBeTruthy()
-
-      await $`mkdir -p ${tmp.path}/sub/dir`.quiet()
-      await Filesystem.write(`${tmp.path}/sub/dir/target.txt`, "target content")
-      await fs.symlink(`${tmp.path}/sub/dir/target.txt`, `${tmp.path}/sub/dir/link.txt`, "file")
-      await fs.symlink(`${tmp.path}/sub`, `${tmp.path}/sub-link`, "dir")
-
-      const patch = await run(tmp.path, (snapshot) => snapshot.patch(before!))
+    }),
+  ),
+  { git: true },
+)
+
+it.instance(
+  "nested symlinks",
+  withTrackedSnapshot(({ tmp, snapshot, before }) =>
+    Effect.gen(function* () {
+      yield* mkdirp(`${tmp.path}/sub/dir`)
+      yield* write(`${tmp.path}/sub/dir/target.txt`, "target content")
+      yield* Effect.promise(() => fs.symlink(`${tmp.path}/sub/dir/target.txt`, `${tmp.path}/sub/dir/link.txt`, "file"))
+      yield* Effect.promise(() => fs.symlink(`${tmp.path}/sub`, `${tmp.path}/sub-link`, "dir"))
+      const patch = yield* snapshot.patch(before)
       expect(patch.files).toContain(fwd(tmp.path, "sub", "dir", "link.txt"))
       expect(patch.files).toContain(fwd(tmp.path, "sub-link"))
-    },
-  })
-})
-
-test("file permissions and ownership changes", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      const before = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(before).toBeTruthy()
-
-      // Change permissions multiple times
-      await $`chmod 600 ${tmp.path}/a.txt`.quiet()
-      await $`chmod 755 ${tmp.path}/a.txt`.quiet()
-      await $`chmod 644 ${tmp.path}/a.txt`.quiet()
-
-      const patch = await run(tmp.path, (snapshot) => snapshot.patch(before!))
-      // Note: git doesn't track permission changes on existing files by default
-      // Only tracks executable bit when files are first added
-      expect(patch.files.length).toBe(0)
-    },
-  })
-})
-
-test("circular symlinks", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      const before = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(before).toBeTruthy()
-
-      // Create circular symlink
-      await fs.symlink(`${tmp.path}/circular`, `${tmp.path}/circular`, "dir").catch(() => {})
-
-      const patch = await run(tmp.path, (snapshot) => snapshot.patch(before!))
-      expect(patch.files.length).toBeGreaterThanOrEqual(0) // Should not crash
-    },
-  })
-})
-
-test("source project gitignore is respected - ignored files are not snapshotted", async () => {
-  await using tmp = await tmpdir({
-    git: true,
-    init: async (dir) => {
-      // Create gitignore BEFORE any tracking
-      await Filesystem.write(`${dir}/.gitignore`, "*.ignored\nbuild/\nnode_modules/\n")
-      await Filesystem.write(`${dir}/tracked.txt`, "tracked content")
-      await Filesystem.write(`${dir}/ignored.ignored`, "ignored content")
-      await $`mkdir -p ${dir}/build`.quiet()
-      await Filesystem.write(`${dir}/build/output.js`, "build output")
-      await Filesystem.write(`${dir}/normal.js`, "normal js")
-      await $`git add .`.cwd(dir).quiet()
-      await $`git commit -m init`.cwd(dir).quiet()
-    },
-  })
-
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      const before = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(before).toBeTruthy()
-
-      // Modify tracked files and create new ones - some ignored, some not
-      await Filesystem.write(`${tmp.path}/tracked.txt`, "modified tracked")
-      await Filesystem.write(`${tmp.path}/new.ignored`, "new ignored")
-      await Filesystem.write(`${tmp.path}/new-tracked.txt`, "new tracked")
-      await Filesystem.write(`${tmp.path}/build/new-build.js`, "new build file")
-
-      const patch = await run(tmp.path, (snapshot) => snapshot.patch(before!))
-
-      // Modified and new tracked files should be in snapshot
-      expect(patch.files).toContain(fwd(tmp.path, "new-tracked.txt"))
-      expect(patch.files).toContain(fwd(tmp.path, "tracked.txt"))
-
-      // Ignored files should NOT be in snapshot
-      expect(patch.files).not.toContain(fwd(tmp.path, "new.ignored"))
-      expect(patch.files).not.toContain(fwd(tmp.path, "ignored.ignored"))
-      expect(patch.files).not.toContain(fwd(tmp.path, "build/output.js"))
-      expect(patch.files).not.toContain(fwd(tmp.path, "build/new-build.js"))
-    },
-  })
-})
-
-test("gitignore changes", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      const before = await run(tmp.path, (snapshot) => snapshot.track())
+    }),
+  ),
+  { git: true },
+)
+
+it.instance(
+  "file permissions and ownership changes",
+  withTrackedSnapshot(({ tmp, snapshot, before }) =>
+    Effect.gen(function* () {
+      yield* Effect.promise(() => fs.chmod(`${tmp.path}/a.txt`, 0o600))
+      yield* Effect.promise(() => fs.chmod(`${tmp.path}/a.txt`, 0o755))
+      yield* Effect.promise(() => fs.chmod(`${tmp.path}/a.txt`, 0o644))
+      expect((yield* snapshot.patch(before)).files.length).toBe(0)
+    }),
+  ),
+  { git: true },
+)
+
+it.instance(
+  "circular symlinks",
+  withTrackedSnapshot(({ tmp, snapshot, before }) =>
+    Effect.gen(function* () {
+      yield* Effect.promise(() =>
+        fs.symlink(`${tmp.path}/circular`, `${tmp.path}/circular`, "dir").catch(() => undefined),
+      )
+      expect((yield* snapshot.patch(before)).files.length).toBeGreaterThanOrEqual(0)
+    }),
+  ),
+  { git: true },
+)
+
+it.live(
+  "source project gitignore is respected - ignored files are not snapshotted",
+  Effect.gen(function* () {
+    const dir = yield* scopedGitTmpdir()
+    yield* write(`${dir}/.gitignore`, "*.ignored\nbuild/\nnode_modules/\n")
+    yield* write(`${dir}/tracked.txt`, "tracked content")
+    yield* write(`${dir}/ignored.ignored`, "ignored content")
+    yield* mkdirp(`${dir}/build`)
+    yield* write(`${dir}/build/output.js`, "build output")
+    yield* write(`${dir}/normal.js`, "normal js")
+    yield* exec(dir, ["git", "add", "."])
+    yield* exec(dir, ["git", "commit", "-m", "init"])
+    yield* Effect.gen(function* () {
+      const snapshot = yield* Snapshot.Service
+      const before = yield* snapshot.track()
       expect(before).toBeTruthy()
-
-      await Filesystem.write(`${tmp.path}/.gitignore`, "*.ignored")
-      await Filesystem.write(`${tmp.path}/test.ignored`, "ignored content")
-      await Filesystem.write(`${tmp.path}/normal.txt`, "normal content")
-
-      const patch = await run(tmp.path, (snapshot) => snapshot.patch(before!))
-
-      // Should track gitignore itself
+      yield* write(`${dir}/tracked.txt`, "modified tracked")
+      yield* write(`${dir}/new.ignored`, "new ignored")
+      yield* write(`${dir}/new-tracked.txt`, "new tracked")
+      yield* write(`${dir}/build/new-build.js`, "new build file")
+      const patch = yield* snapshot.patch(before!)
+      expect(patch.files).toContain(fwd(dir, "new-tracked.txt"))
+      expect(patch.files).toContain(fwd(dir, "tracked.txt"))
+      expect(patch.files).not.toContain(fwd(dir, "new.ignored"))
+      expect(patch.files).not.toContain(fwd(dir, "ignored.ignored"))
+      expect(patch.files).not.toContain(fwd(dir, "build/output.js"))
+      expect(patch.files).not.toContain(fwd(dir, "build/new-build.js"))
+    }).pipe(provideInstance(dir))
+  }),
+)
+
+it.instance(
+  "gitignore changes",
+  withTrackedSnapshot(({ tmp, snapshot, before }) =>
+    Effect.gen(function* () {
+      yield* write(`${tmp.path}/.gitignore`, "*.ignored")
+      yield* write(`${tmp.path}/test.ignored`, "ignored content")
+      yield* write(`${tmp.path}/normal.txt`, "normal content")
+      const patch = yield* snapshot.patch(before)
       expect(patch.files).toContain(fwd(tmp.path, ".gitignore"))
-      // Should track normal files
       expect(patch.files).toContain(fwd(tmp.path, "normal.txt"))
-      // Should not track ignored files (git won't see them)
       expect(patch.files).not.toContain(fwd(tmp.path, "test.ignored"))
-    },
-  })
-})
-
-test("files tracked in snapshot but now gitignored are filtered out", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      // First, create a file and snapshot it
-      await Filesystem.write(`${tmp.path}/later-ignored.txt`, "initial content")
-      const before = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(before).toBeTruthy()
-
-      // Modify the file (so it appears in diff-files)
-      await Filesystem.write(`${tmp.path}/later-ignored.txt`, "modified content")
-
-      // Now add gitignore that would exclude this file
-      await Filesystem.write(`${tmp.path}/.gitignore`, "later-ignored.txt\n")
-
-      // Also create another tracked file
-      await Filesystem.write(`${tmp.path}/still-tracked.txt`, "new tracked file")
-
-      const patch = await run(tmp.path, (snapshot) => snapshot.patch(before!))
-
-      // The file that is now gitignored should NOT appear, even though it was
-      // previously tracked and modified
-      expect(patch.files).not.toContain(fwd(tmp.path, "later-ignored.txt"))
-
-      // The gitignore file itself should appear
-      expect(patch.files).toContain(fwd(tmp.path, ".gitignore"))
-
-      // Other tracked files should appear
-      expect(patch.files).toContain(fwd(tmp.path, "still-tracked.txt"))
-    },
-  })
-})
-
-test("gitignore updated between track calls filters from diff", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      // a.txt is already committed from bootstrap - track it in snapshot
-      const before = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(before).toBeTruthy()
-
-      // Modify a.txt (so it appears in diff-files)
-      await Filesystem.write(`${tmp.path}/a.txt`, "modified content")
-
-      // Now add gitignore that would exclude a.txt
-      await Filesystem.write(`${tmp.path}/.gitignore`, "a.txt\n")
-
-      // Also modify b.txt which is not gitignored
-      await Filesystem.write(`${tmp.path}/b.txt`, "also modified")
-
-      // Second track - should not include a.txt even though it changed
-      const after = await run(tmp.path, (snapshot) => snapshot.track())
+    }),
+  ),
+  { git: true },
+)
+
+it.instance(
+  "files tracked in snapshot but now gitignored are filtered out",
+  Effect.gen(function* () {
+    const tmp = yield* bootstrap()
+    const snapshot = yield* Snapshot.Service
+    yield* write(`${tmp.path}/later-ignored.txt`, "initial content")
+    const before = yield* snapshot.track()
+    expect(before).toBeTruthy()
+    yield* write(`${tmp.path}/later-ignored.txt`, "modified content")
+    yield* write(`${tmp.path}/.gitignore`, "later-ignored.txt\n")
+    yield* write(`${tmp.path}/still-tracked.txt`, "new tracked file")
+    const patch = yield* snapshot.patch(before!)
+    expect(patch.files).not.toContain(fwd(tmp.path, "later-ignored.txt"))
+    expect(patch.files).toContain(fwd(tmp.path, ".gitignore"))
+    expect(patch.files).toContain(fwd(tmp.path, "still-tracked.txt"))
+  }),
+  { git: true },
+)
+
+it.instance(
+  "gitignore updated between track calls filters from diff",
+  withTrackedSnapshot(({ tmp, snapshot, before }) =>
+    Effect.gen(function* () {
+      yield* write(`${tmp.path}/a.txt`, "modified content")
+      yield* write(`${tmp.path}/.gitignore`, "a.txt\n")
+      yield* write(`${tmp.path}/b.txt`, "also modified")
+      const after = yield* snapshot.track()
       expect(after).toBeTruthy()
-
-      // Verify a.txt is NOT in the diff between snapshots
-      const diffs = await run(tmp.path, (snapshot) => snapshot.diffFull(before!, after!))
+      const diffs = yield* snapshot.diffFull(before, after!)
       expect(diffs.some((x) => x.file === "a.txt")).toBe(false)
-
-      // But .gitignore should be in the diff
       expect(diffs.some((x) => x.file === ".gitignore")).toBe(true)
-
-      // b.txt should be in the diff (not gitignored)
       expect(diffs.some((x) => x.file === "b.txt")).toBe(true)
-    },
-  })
-})
-
-test("git info exclude changes", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      const before = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(before).toBeTruthy()
-
+    }),
+  ),
+  { git: true },
+)
+
+it.instance(
+  "git info exclude changes",
+  withTrackedSnapshot(({ tmp, snapshot, before }) =>
+    Effect.gen(function* () {
       const file = `${tmp.path}/.git/info/exclude`
-      const text = await Bun.file(file).text()
-      await Bun.write(file, `${text.trimEnd()}\nignored.txt\n`)
-      await Bun.write(`${tmp.path}/ignored.txt`, "ignored content")
-      await Bun.write(`${tmp.path}/normal.txt`, "normal content")
-
-      const patch = await run(tmp.path, (snapshot) => snapshot.patch(before!))
+      yield* write(file, `${(yield* Effect.promise(() => Bun.file(file).text())).trimEnd()}\nignored.txt\n`)
+      yield* write(`${tmp.path}/ignored.txt`, "ignored content")
+      yield* write(`${tmp.path}/normal.txt`, "normal content")
+      const patch = yield* snapshot.patch(before)
       expect(patch.files).toContain(fwd(tmp.path, "normal.txt"))
       expect(patch.files).not.toContain(fwd(tmp.path, "ignored.txt"))
-
-      const after = await run(tmp.path, (snapshot) => snapshot.track())
-      const diffs = await run(tmp.path, (snapshot) => snapshot.diffFull(before!, after!))
+      const after = yield* snapshot.track()
+      const diffs = yield* snapshot.diffFull(before, after!)
       expect(diffs.some((x) => x.file === "normal.txt")).toBe(true)
       expect(diffs.some((x) => x.file === "ignored.txt")).toBe(false)
-    },
-  })
-})
-
-test("git info exclude keeps global excludes", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      const global = `${tmp.path}/global.ignore`
-      const config = `${tmp.path}/global.gitconfig`
-      await Bun.write(global, "global.tmp\n")
-      await Bun.write(config, `[core]\n\texcludesFile = ${global.replaceAll("\\", "/")}\n`)
-
-      const prev = process.env.GIT_CONFIG_GLOBAL
-      process.env.GIT_CONFIG_GLOBAL = config
-      try {
-        const before = await run(tmp.path, (snapshot) => snapshot.track())
+    }),
+  ),
+  { git: true },
+)
+
+it.instance(
+  "git info exclude keeps global excludes",
+  Effect.gen(function* () {
+    const tmp = yield* bootstrap()
+    const global = `${tmp.path}/global.ignore`
+    const config = `${tmp.path}/global.gitconfig`
+    yield* write(global, "global.tmp\n")
+    yield* write(config, `[core]\n\texcludesFile = ${global.replaceAll("\\", "/")}\n`)
+    yield* withGitConfigGlobal(
+      config,
+      Effect.gen(function* () {
+        const snapshot = yield* Snapshot.Service
+        const before = yield* snapshot.track()
         expect(before).toBeTruthy()
-
         const file = `${tmp.path}/.git/info/exclude`
-        const text = await Bun.file(file).text()
-        await Bun.write(file, `${text.trimEnd()}\ninfo.tmp\n`)
-
-        await Bun.write(`${tmp.path}/global.tmp`, "global content")
-        await Bun.write(`${tmp.path}/info.tmp`, "info content")
-        await Bun.write(`${tmp.path}/normal.txt`, "normal content")
-
-        const patch = await run(tmp.path, (snapshot) => snapshot.patch(before!))
+        yield* write(file, `${(yield* Effect.promise(() => Bun.file(file).text())).trimEnd()}\ninfo.tmp\n`)
+        yield* write(`${tmp.path}/global.tmp`, "global content")
+        yield* write(`${tmp.path}/info.tmp`, "info content")
+        yield* write(`${tmp.path}/normal.txt`, "normal content")
+        const patch = yield* snapshot.patch(before!)
         expect(patch.files).toContain(fwd(tmp.path, "normal.txt"))
         expect(patch.files).not.toContain(fwd(tmp.path, "global.tmp"))
         expect(patch.files).not.toContain(fwd(tmp.path, "info.tmp"))
-      } finally {
-        if (prev) process.env.GIT_CONFIG_GLOBAL = prev
-        else delete process.env.GIT_CONFIG_GLOBAL
-      }
-    },
-  })
-})
-
-test("concurrent file operations during patch", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      const before = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(before).toBeTruthy()
-
-      // Start creating files
-      const createPromise = (async () => {
+      }),
+    )
+  }),
+  { git: true },
+)
+
+it.instance(
+  "concurrent file operations during patch",
+  withTrackedSnapshot(({ tmp, snapshot, before }) =>
+    Effect.gen(function* () {
+      const fiber = yield* Effect.gen(function* () {
         for (let i = 0; i < 10; i++) {
-          await Filesystem.write(`${tmp.path}/concurrent${i}.txt`, `concurrent${i}`)
-          // Small delay to simulate concurrent operations
-          await new Promise((resolve) => setTimeout(resolve, 1))
+          yield* write(`${tmp.path}/concurrent${i}.txt`, `concurrent${i}`)
+          yield* Effect.sleep("1 millis")
         }
-      })()
-
-      // Get patch while files are being created
-      const patchPromise = run(tmp.path, (snapshot) => snapshot.patch(before!))
-
-      await createPromise
-      const patch = await patchPromise
-
-      // Should capture some or all of the concurrent files
+      }).pipe(Effect.forkScoped)
+      const patch = yield* snapshot.patch(before)
+      yield* Fiber.join(fiber)
       expect(patch.files.length).toBeGreaterThanOrEqual(0)
-    },
-  })
-})
-
-test("snapshot state isolation between projects", async () => {
-  // Test that different projects don't interfere with each other
-  await using tmp1 = await bootstrap()
-  await using tmp2 = await bootstrap()
-
-  await WithInstance.provide({
-    directory: tmp1.path,
-    fn: async () => {
-      const before1 = await run(tmp1.path, (snapshot) => snapshot.track())
-      await Filesystem.write(`${tmp1.path}/project1.txt`, "project1 content")
-      const patch1 = await run(tmp1.path, (snapshot) => snapshot.patch(before1!))
+    }),
+  ),
+  { git: true },
+)
+
+it.live(
+  "snapshot state isolation between projects",
+  Effect.gen(function* () {
+    const tmp1 = yield* bootstrapScoped()
+    const tmp2 = yield* bootstrapScoped()
+    yield* Effect.gen(function* () {
+      const snapshot = yield* Snapshot.Service
+      const before1 = yield* snapshot.track()
+      yield* write(`${tmp1.path}/project1.txt`, "project1 content")
+      const patch1 = yield* snapshot.patch(before1!)
       expect(patch1.files).toContain(fwd(tmp1.path, "project1.txt"))
-    },
-  })
-
-  await WithInstance.provide({
-    directory: tmp2.path,
-    fn: async () => {
-      const before2 = await run(tmp2.path, (snapshot) => snapshot.track())
-      await Filesystem.write(`${tmp2.path}/project2.txt`, "project2 content")
-      const patch2 = await run(tmp2.path, (snapshot) => snapshot.patch(before2!))
+    }).pipe(provideInstance(tmp1.path))
+    yield* Effect.gen(function* () {
+      const snapshot = yield* Snapshot.Service
+      const before2 = yield* snapshot.track()
+      yield* write(`${tmp2.path}/project2.txt`, "project2 content")
+      const patch2 = yield* snapshot.patch(before2!)
       expect(patch2.files).toContain(fwd(tmp2.path, "project2.txt"))
-
-      // Ensure project1 files don't appear in project2
-      expect(patch2.files).not.toContain(fwd(tmp1?.path ?? "", "project1.txt"))
-    },
-  })
-})
-
-test("patch detects changes in secondary worktree", async () => {
-  await using tmp = await bootstrap()
-  const worktreePath = `${tmp.path}-worktree`
-  await $`git worktree add ${worktreePath} HEAD`.cwd(tmp.path).quiet()
-
-  try {
-    await WithInstance.provide({
-      directory: tmp.path,
-      fn: async () => {
-        expect(await run(tmp.path, (snapshot) => snapshot.track())).toBeTruthy()
-      },
-    })
-
-    await WithInstance.provide({
-      directory: worktreePath,
-      fn: async () => {
-        const before = await run(worktreePath, (snapshot) => snapshot.track())
-        expect(before).toBeTruthy()
-
-        const worktreeFile = fwd(worktreePath, "worktree.txt")
-        await Filesystem.write(worktreeFile, "worktree content")
-
-        const patch = await run(worktreePath, (snapshot) => snapshot.patch(before!))
-        expect(patch.files).toContain(worktreeFile)
-      },
-    })
-  } finally {
-    await $`git worktree remove --force ${worktreePath}`.cwd(tmp.path).quiet().nothrow()
-    await $`rm -rf ${worktreePath}`.quiet()
-  }
-})
-
-test("revert only removes files in invoking worktree", async () => {
-  await using tmp = await bootstrap()
-  const worktreePath = `${tmp.path}-worktree`
-  await $`git worktree add ${worktreePath} HEAD`.cwd(tmp.path).quiet()
-
-  try {
-    await WithInstance.provide({
-      directory: tmp.path,
-      fn: async () => {
-        expect(await run(tmp.path, (snapshot) => snapshot.track())).toBeTruthy()
-      },
-    })
+      expect(patch2.files).not.toContain(fwd(tmp1.path, "project1.txt"))
+    }).pipe(provideInstance(tmp2.path))
+  }),
+)
+
+it.live(
+  "patch detects changes in secondary worktree",
+  Effect.gen(function* () {
+    const tmp = yield* bootstrapScoped()
+    const worktreePath = `${tmp.path}-worktree`
+    yield* exec(tmp.path, ["git", "worktree", "add", worktreePath, "HEAD"])
+    yield* Effect.addFinalizer(() => cleanupWorktree(tmp.path, worktreePath))
+    yield* Effect.gen(function* () {
+      const snapshot = yield* Snapshot.Service
+      expect(yield* snapshot.track()).toBeTruthy()
+    }).pipe(provideInstance(tmp.path))
+    yield* Effect.gen(function* () {
+      const snapshot = yield* Snapshot.Service
+      const before = yield* snapshot.track()
+      expect(before).toBeTruthy()
+      const worktreeFile = fwd(worktreePath, "worktree.txt")
+      yield* write(worktreeFile, "worktree content")
+      expect((yield* snapshot.patch(before!)).files).toContain(worktreeFile)
+    }).pipe(provideInstance(worktreePath))
+  }),
+)
+
+it.live(
+  "revert only removes files in invoking worktree",
+  Effect.gen(function* () {
+    const tmp = yield* bootstrapScoped()
+    const worktreePath = `${tmp.path}-worktree`
     const primaryFile = `${tmp.path}/worktree.txt`
-    await Filesystem.write(primaryFile, "primary content")
-
-    await WithInstance.provide({
-      directory: worktreePath,
-      fn: async () => {
-        const before = await run(worktreePath, (snapshot) => snapshot.track())
-        expect(before).toBeTruthy()
-
-        const worktreeFile = fwd(worktreePath, "worktree.txt")
-        await Filesystem.write(worktreeFile, "worktree content")
-
-        const patch = await run(worktreePath, (snapshot) => snapshot.patch(before!))
-        await run(worktreePath, (snapshot) => snapshot.revert([patch]))
-
-        expect(
-          await fs
-            .access(worktreeFile)
-            .then(() => true)
-            .catch(() => false),
-        ).toBe(false)
-      },
-    })
-
-    expect(await fs.readFile(primaryFile, "utf-8")).toBe("primary content")
-  } finally {
-    await $`git worktree remove --force ${worktreePath}`.cwd(tmp.path).quiet().nothrow()
-    await $`rm -rf ${worktreePath}`.quiet()
-    await $`rm -f ${tmp.path}/worktree.txt`.quiet()
-  }
-})
-
-test("diff reports worktree-only/shared edits and ignores primary-only", async () => {
-  await using tmp = await bootstrap()
-  const worktreePath = `${tmp.path}-worktree`
-  await $`git worktree add ${worktreePath} HEAD`.cwd(tmp.path).quiet()
-
-  try {
-    await WithInstance.provide({
-      directory: tmp.path,
-      fn: async () => {
-        expect(await run(tmp.path, (snapshot) => snapshot.track())).toBeTruthy()
-      },
-    })
-
-    await WithInstance.provide({
-      directory: worktreePath,
-      fn: async () => {
-        const before = await run(worktreePath, (snapshot) => snapshot.track())
-        expect(before).toBeTruthy()
-
-        await Filesystem.write(`${worktreePath}/worktree-only.txt`, "worktree diff content")
-        await Filesystem.write(`${worktreePath}/shared.txt`, "worktree edit")
-        await Filesystem.write(`${tmp.path}/shared.txt`, "primary edit")
-        await Filesystem.write(`${tmp.path}/primary-only.txt`, "primary change")
-
-        const diff = await run(worktreePath, (snapshot) => snapshot.diff(before!))
-        expect(diff).toContain("worktree-only.txt")
-        expect(diff).toContain("shared.txt")
-        expect(diff).not.toContain("primary-only.txt")
-      },
-    })
-  } finally {
-    await $`git worktree remove --force ${worktreePath}`.cwd(tmp.path).quiet().nothrow()
-    await $`rm -rf ${worktreePath}`.quiet()
-    await $`rm -f ${tmp.path}/shared.txt`.quiet()
-    await $`rm -f ${tmp.path}/primary-only.txt`.quiet()
-  }
-})
-
-test("track with no changes returns same hash", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      const hash1 = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(hash1).toBeTruthy()
-
-      // Track again with no changes
-      const hash2 = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(hash2).toBe(hash1!)
-
-      // Track again
-      const hash3 = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(hash3).toBe(hash1!)
-    },
-  })
-})
-
-test("diff function with various changes", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      const before = await run(tmp.path, (snapshot) => snapshot.track())
+    yield* exec(tmp.path, ["git", "worktree", "add", worktreePath, "HEAD"])
+    yield* Effect.addFinalizer(() => cleanupWorktree(tmp.path, worktreePath, [primaryFile]))
+    yield* Effect.gen(function* () {
+      const snapshot = yield* Snapshot.Service
+      expect(yield* snapshot.track()).toBeTruthy()
+    }).pipe(provideInstance(tmp.path))
+    yield* write(primaryFile, "primary content")
+    yield* Effect.gen(function* () {
+      const snapshot = yield* Snapshot.Service
+      const before = yield* snapshot.track()
       expect(before).toBeTruthy()
-
-      // Make various changes
-      await $`rm ${tmp.path}/a.txt`.quiet()
-      await Filesystem.write(`${tmp.path}/new.txt`, "new content")
-      await Filesystem.write(`${tmp.path}/b.txt`, "modified content")
-
-      const diff = await run(tmp.path, (snapshot) => snapshot.diff(before!))
+      const worktreeFile = fwd(worktreePath, "worktree.txt")
+      yield* write(worktreeFile, "worktree content")
+      const patch = yield* snapshot.patch(before!)
+      yield* snapshot.revert([patch])
+      expect(yield* exists(worktreeFile)).toBe(false)
+    }).pipe(provideInstance(worktreePath))
+    expect(yield* readText(primaryFile)).toBe("primary content")
+  }),
+)
+
+it.live(
+  "diff reports worktree-only/shared edits and ignores primary-only",
+  Effect.gen(function* () {
+    const tmp = yield* bootstrapScoped()
+    const worktreePath = `${tmp.path}-worktree`
+    yield* exec(tmp.path, ["git", "worktree", "add", worktreePath, "HEAD"])
+    yield* Effect.addFinalizer(() =>
+      cleanupWorktree(tmp.path, worktreePath, [`${tmp.path}/shared.txt`, `${tmp.path}/primary-only.txt`]),
+    )
+    yield* Effect.gen(function* () {
+      const snapshot = yield* Snapshot.Service
+      expect(yield* snapshot.track()).toBeTruthy()
+    }).pipe(provideInstance(tmp.path))
+    yield* Effect.gen(function* () {
+      const snapshot = yield* Snapshot.Service
+      const before = yield* snapshot.track()
+      expect(before).toBeTruthy()
+      yield* write(`${worktreePath}/worktree-only.txt`, "worktree diff content")
+      yield* write(`${worktreePath}/shared.txt`, "worktree edit")
+      yield* write(`${tmp.path}/shared.txt`, "primary edit")
+      yield* write(`${tmp.path}/primary-only.txt`, "primary change")
+      const diff = yield* snapshot.diff(before!)
+      expect(diff).toContain("worktree-only.txt")
+      expect(diff).toContain("shared.txt")
+      expect(diff).not.toContain("primary-only.txt")
+    }).pipe(provideInstance(worktreePath))
+  }),
+)
+
+it.instance(
+  "track with no changes returns same hash",
+  withTrackedSnapshot(({ snapshot, before }) =>
+    Effect.gen(function* () {
+      expect(yield* snapshot.track()).toBe(before)
+      expect(yield* snapshot.track()).toBe(before)
+    }),
+  ),
+  { git: true },
+)
+
+it.instance(
+  "diff function with various changes",
+  withTrackedSnapshot(({ tmp, snapshot, before }) =>
+    Effect.gen(function* () {
+      yield* rm(`${tmp.path}/a.txt`)
+      yield* write(`${tmp.path}/new.txt`, "new content")
+      yield* write(`${tmp.path}/b.txt`, "modified content")
+      const diff = yield* snapshot.diff(before)
       expect(diff).toContain("a.txt")
       expect(diff).toContain("b.txt")
       expect(diff).toContain("new.txt")
-    },
-  })
-})
-
-test("restore function", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      const before = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(before).toBeTruthy()
-
-      // Make changes
-      await $`rm ${tmp.path}/a.txt`.quiet()
-      await Filesystem.write(`${tmp.path}/new.txt`, "new content")
-      await Filesystem.write(`${tmp.path}/b.txt`, "modified")
-
-      // Restore to original state
-      await run(tmp.path, (snapshot) => snapshot.restore(before!))
-
-      expect(
-        await fs
-          .access(`${tmp.path}/a.txt`)
-          .then(() => true)
-          .catch(() => false),
-      ).toBe(true)
-      expect(await fs.readFile(`${tmp.path}/a.txt`, "utf-8")).toBe(tmp.extra.aContent)
-      expect(
-        await fs
-          .access(`${tmp.path}/new.txt`)
-          .then(() => true)
-          .catch(() => false),
-      ).toBe(true) // New files should remain
-      expect(await fs.readFile(`${tmp.path}/b.txt`, "utf-8")).toBe(tmp.extra.bContent)
-    },
-  })
-})
-
-test("revert should not delete files that existed but were deleted in snapshot", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      const snapshot1 = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(snapshot1).toBeTruthy()
-
-      await $`rm ${tmp.path}/a.txt`.quiet()
-
-      const snapshot2 = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(snapshot2).toBeTruthy()
-
-      await Filesystem.write(`${tmp.path}/a.txt`, "recreated content")
-
-      const patch = await run(tmp.path, (snapshot) => snapshot.patch(snapshot2!))
-      expect(patch.files).toContain(fwd(tmp.path, "a.txt"))
-
-      await run(tmp.path, (snapshot) => snapshot.revert([patch]))
-
-      expect(
-        await fs
-          .access(`${tmp.path}/a.txt`)
-          .then(() => true)
-          .catch(() => false),
-      ).toBe(false)
-    },
-  })
-})
-
-test("revert preserves file that existed in snapshot when deleted then recreated", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      await Filesystem.write(`${tmp.path}/existing.txt`, "original content")
-
-      const hash = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(hash).toBeTruthy()
-
-      await $`rm ${tmp.path}/existing.txt`.quiet()
-      await Filesystem.write(`${tmp.path}/existing.txt`, "recreated")
-      await Filesystem.write(`${tmp.path}/newfile.txt`, "new")
-
-      const patch = await run(tmp.path, (snapshot) => snapshot.patch(hash!))
-      expect(patch.files).toContain(fwd(tmp.path, "existing.txt"))
-      expect(patch.files).toContain(fwd(tmp.path, "newfile.txt"))
-
-      await run(tmp.path, (snapshot) => snapshot.revert([patch]))
-
-      expect(
-        await fs
-          .access(`${tmp.path}/newfile.txt`)
-          .then(() => true)
-          .catch(() => false),
-      ).toBe(false)
-      expect(
-        await fs
-          .access(`${tmp.path}/existing.txt`)
-          .then(() => true)
-          .catch(() => false),
-      ).toBe(true)
-      expect(await fs.readFile(`${tmp.path}/existing.txt`, "utf-8")).toBe("original content")
-    },
-  })
-})
-
-test("diffFull sets status based on git change type", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      await Filesystem.write(`${tmp.path}/grow.txt`, "one\n")
-      await Filesystem.write(`${tmp.path}/trim.txt`, "line1\nline2\n")
-      await Filesystem.write(`${tmp.path}/delete.txt`, "gone")
-
-      const before = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(before).toBeTruthy()
-
-      await Filesystem.write(`${tmp.path}/grow.txt`, "one\ntwo\n")
-      await Filesystem.write(`${tmp.path}/trim.txt`, "line1\n")
-      await $`rm ${tmp.path}/delete.txt`.quiet()
-      await Filesystem.write(`${tmp.path}/added.txt`, "new")
-
-      const after = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(after).toBeTruthy()
-
-      const diffs = await run(tmp.path, (snapshot) => snapshot.diffFull(before!, after!))
-      expect(diffs.length).toBe(4)
-
-      const added = diffs.find((d) => d.file === "added.txt")
-      expect(added).toBeDefined()
-      expect(added!.status).toBe("added")
-
-      const deleted = diffs.find((d) => d.file === "delete.txt")
-      expect(deleted).toBeDefined()
-      expect(deleted!.status).toBe("deleted")
-
-      const grow = diffs.find((d) => d.file === "grow.txt")
-      expect(grow).toBeDefined()
-      expect(grow!.status).toBe("modified")
-      expect(grow!.additions).toBeGreaterThan(0)
-      expect(grow!.deletions).toBe(0)
-
-      const trim = diffs.find((d) => d.file === "trim.txt")
-      expect(trim).toBeDefined()
-      expect(trim!.status).toBe("modified")
-      expect(trim!.additions).toBe(0)
-      expect(trim!.deletions).toBeGreaterThan(0)
-    },
-  })
-})
-
-test("diffFull with new file additions", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      const before = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(before).toBeTruthy()
-
-      await Filesystem.write(`${tmp.path}/new.txt`, "new content")
-
-      const after = await run(tmp.path, (snapshot) => snapshot.track())
+    }),
+  ),
+  { git: true },
+)
+
+it.instance(
+  "restore function",
+  withTrackedSnapshot(({ tmp, snapshot, before }) =>
+    Effect.gen(function* () {
+      yield* rm(`${tmp.path}/a.txt`)
+      yield* write(`${tmp.path}/new.txt`, "new content")
+      yield* write(`${tmp.path}/b.txt`, "modified")
+      yield* snapshot.restore(before)
+      expect(yield* exists(`${tmp.path}/a.txt`)).toBe(true)
+      expect(yield* readText(`${tmp.path}/a.txt`)).toBe(tmp.extra.aContent)
+      expect(yield* exists(`${tmp.path}/new.txt`)).toBe(true)
+      expect(yield* readText(`${tmp.path}/b.txt`)).toBe(tmp.extra.bContent)
+    }),
+  ),
+  { git: true },
+)
+
+it.instance(
+  "revert should not delete files that existed but were deleted in snapshot",
+  Effect.gen(function* () {
+    const tmp = yield* bootstrap()
+    const snapshot = yield* Snapshot.Service
+    const snapshot1 = yield* snapshot.track()
+    expect(snapshot1).toBeTruthy()
+    yield* rm(`${tmp.path}/a.txt`)
+    const snapshot2 = yield* snapshot.track()
+    expect(snapshot2).toBeTruthy()
+    yield* write(`${tmp.path}/a.txt`, "recreated content")
+    const patch = yield* snapshot.patch(snapshot2!)
+    expect(patch.files).toContain(fwd(tmp.path, "a.txt"))
+    yield* snapshot.revert([patch])
+    expect(yield* exists(`${tmp.path}/a.txt`)).toBe(false)
+  }),
+  { git: true },
+)
+
+it.instance(
+  "revert preserves file that existed in snapshot when deleted then recreated",
+  Effect.gen(function* () {
+    const tmp = yield* bootstrap()
+    const snapshot = yield* Snapshot.Service
+    yield* write(`${tmp.path}/existing.txt`, "original content")
+    const hash = yield* snapshot.track()
+    expect(hash).toBeTruthy()
+    yield* rm(`${tmp.path}/existing.txt`)
+    yield* write(`${tmp.path}/existing.txt`, "recreated")
+    yield* write(`${tmp.path}/newfile.txt`, "new")
+    const patch = yield* snapshot.patch(hash!)
+    expect(patch.files).toContain(fwd(tmp.path, "existing.txt"))
+    expect(patch.files).toContain(fwd(tmp.path, "newfile.txt"))
+    yield* snapshot.revert([patch])
+    expect(yield* exists(`${tmp.path}/newfile.txt`)).toBe(false)
+    expect(yield* exists(`${tmp.path}/existing.txt`)).toBe(true)
+    expect(yield* readText(`${tmp.path}/existing.txt`)).toBe("original content")
+  }),
+  { git: true },
+)
+
+it.instance(
+  "diffFull sets status based on git change type",
+  Effect.gen(function* () {
+    const tmp = yield* bootstrap()
+    const snapshot = yield* Snapshot.Service
+    yield* write(`${tmp.path}/grow.txt`, "one\n")
+    yield* write(`${tmp.path}/trim.txt`, "line1\nline2\n")
+    yield* write(`${tmp.path}/delete.txt`, "gone")
+    const before = yield* snapshot.track()
+    expect(before).toBeTruthy()
+    yield* write(`${tmp.path}/grow.txt`, "one\ntwo\n")
+    yield* write(`${tmp.path}/trim.txt`, "line1\n")
+    yield* rm(`${tmp.path}/delete.txt`)
+    yield* write(`${tmp.path}/added.txt`, "new")
+    const after = yield* snapshot.track()
+    expect(after).toBeTruthy()
+    const diffs = yield* snapshot.diffFull(before!, after!)
+    expect(diffs.length).toBe(4)
+    expect(diffs.find((d) => d.file === "added.txt")!.status).toBe("added")
+    expect(diffs.find((d) => d.file === "delete.txt")!.status).toBe("deleted")
+    const grow = diffs.find((d) => d.file === "grow.txt")!
+    expect(grow.status).toBe("modified")
+    expect(grow.additions).toBeGreaterThan(0)
+    expect(grow.deletions).toBe(0)
+    const trim = diffs.find((d) => d.file === "trim.txt")!
+    expect(trim.status).toBe("modified")
+    expect(trim.additions).toBe(0)
+    expect(trim.deletions).toBeGreaterThan(0)
+  }),
+  { git: true },
+)
+
+it.instance(
+  "diffFull with new file additions",
+  withTrackedSnapshot(({ tmp, snapshot, before }) =>
+    Effect.gen(function* () {
+      yield* write(`${tmp.path}/new.txt`, "new content")
+      const after = yield* snapshot.track()
       expect(after).toBeTruthy()
-
-      const diffs = await run(tmp.path, (snapshot) => snapshot.diffFull(before!, after!))
+      const diffs = yield* snapshot.diffFull(before, after!)
       expect(diffs.length).toBe(1)
-
-      const newFileDiff = diffs[0]
-      expect(newFileDiff.file).toBe("new.txt")
-      expect(newFileDiff.patch).toContain("+new content")
-      expect(newFileDiff.additions).toBe(1)
-      expect(newFileDiff.deletions).toBe(0)
-    },
-  })
-})
-
-test("diffFull with a large interleaved mixed diff", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      const ids = Array.from({ length: 60 }, (_, i) => i.toString().padStart(3, "0"))
-      const mod = ids.map((id) => fwd(tmp.path, "mix", `${id}-mod.txt`))
-      const del = ids.map((id) => fwd(tmp.path, "mix", `${id}-del.txt`))
-      const add = ids.map((id) => fwd(tmp.path, "mix", `${id}-add.txt`))
-      const bin = ids.map((id) => fwd(tmp.path, "mix", `${id}-bin.bin`))
-
-      await $`mkdir -p ${tmp.path}/mix`.quiet()
-      await Promise.all([
-        ...mod.map((file, i) => Filesystem.write(file, `before-${ids[i]}-é\n🙂\nline`)),
-        ...del.map((file, i) => Filesystem.write(file, `gone-${ids[i]}\n你好`)),
-        ...bin.map((file, i) => Filesystem.write(file, new Uint8Array([0, i, 255, i % 251]))),
-      ])
-
-      const before = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(before).toBeTruthy()
-
-      await Promise.all([
-        ...mod.map((file, i) => Filesystem.write(file, `after-${ids[i]}-é\n🚀\nline`)),
-        ...add.map((file, i) => Filesystem.write(file, `new-${ids[i]}\nこんにちは`)),
-        ...bin.map((file, i) => Filesystem.write(file, new Uint8Array([9, i, 8, i % 251]))),
-        ...del.map((file) => fs.rm(file)),
-      ])
-
-      const after = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(after).toBeTruthy()
-
-      const diffs = await run(tmp.path, (snapshot) => snapshot.diffFull(before!, after!))
-      expect(diffs).toHaveLength(ids.length * 4)
-
-      const map = new Map(diffs.map((item) => [item.file, item]))
-      for (let i = 0; i < ids.length; i++) {
-        const m = map.get(fwd("mix", `${ids[i]}-mod.txt`))
-        expect(m).toBeDefined()
-        expect(m!.patch).toContain(`-before-${ids[i]}-é`)
-        expect(m!.patch).toContain(`+after-${ids[i]}-é`)
-        expect(m!.status).toBe("modified")
-
-        const d = map.get(fwd("mix", `${ids[i]}-del.txt`))
-        expect(d).toBeDefined()
-        expect(d!.patch).toContain(`-gone-${ids[i]}`)
-        expect(d!.status).toBe("deleted")
-
-        const a = map.get(fwd("mix", `${ids[i]}-add.txt`))
-        expect(a).toBeDefined()
-        expect(a!.patch).toContain(`+new-${ids[i]}`)
-        expect(a!.status).toBe("added")
-
-        const b = map.get(fwd("mix", `${ids[i]}-bin.bin`))
-        expect(b).toBeDefined()
-        expect(b!.patch).toBe("")
-        expect(b!.additions).toBe(0)
-        expect(b!.deletions).toBe(0)
-        expect(b!.status).toBe("modified")
-      }
-    },
-  })
-})
-
-test("diffFull preserves git diff order across batch boundaries", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      const ids = Array.from({ length: 140 }, (_, i) => i.toString().padStart(3, "0"))
-
-      await $`mkdir -p ${tmp.path}/order`.quiet()
-      await Promise.all(ids.map((id) => Filesystem.write(`${tmp.path}/order/${id}.txt`, `before-${id}`)))
-
-      const before = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(before).toBeTruthy()
-
-      await Promise.all(ids.map((id) => Filesystem.write(`${tmp.path}/order/${id}.txt`, `after-${id}`)))
-
-      const after = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(after).toBeTruthy()
-
-      const expected = ids.map((id) => `order/${id}.txt`)
-
-      const diffs = await run(tmp.path, (snapshot) => snapshot.diffFull(before!, after!))
-      expect(diffs.map((item) => item.file)).toEqual(expected)
-    },
-  })
-})
-
-test("diffFull with file modifications", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      const before = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(before).toBeTruthy()
-
-      await Filesystem.write(`${tmp.path}/b.txt`, "modified content")
-
-      const after = await run(tmp.path, (snapshot) => snapshot.track())
+      expect(diffs[0].file).toBe("new.txt")
+      expect(diffs[0].patch).toContain("+new content")
+      expect(diffs[0].additions).toBe(1)
+      expect(diffs[0].deletions).toBe(0)
+    }),
+  ),
+  { git: true },
+)
+
+it.instance(
+  "diffFull with a large interleaved mixed diff",
+  Effect.gen(function* () {
+    const tmp = yield* bootstrap()
+    const snapshot = yield* Snapshot.Service
+    const ids = Array.from({ length: 60 }, (_, i) => i.toString().padStart(3, "0"))
+    const mod = ids.map((id) => fwd(tmp.path, "mix", `${id}-mod.txt`))
+    const del = ids.map((id) => fwd(tmp.path, "mix", `${id}-del.txt`))
+    const add = ids.map((id) => fwd(tmp.path, "mix", `${id}-add.txt`))
+    const bin = ids.map((id) => fwd(tmp.path, "mix", `${id}-bin.bin`))
+    yield* mkdirp(`${tmp.path}/mix`)
+    yield* Effect.all(
+      [
+        ...mod.map((file, i) => write(file, `before-${ids[i]}-é\n🙂\nline`)),
+        ...del.map((file, i) => write(file, `gone-${ids[i]}\n你好`)),
+        ...bin.map((file, i) => write(file, new Uint8Array([0, i, 255, i % 251]))),
+      ],
+      { concurrency: "unbounded" },
+    )
+    const before = yield* snapshot.track()
+    expect(before).toBeTruthy()
+    yield* Effect.all(
+      [
+        ...mod.map((file, i) => write(file, `after-${ids[i]}-é\n🚀\nline`)),
+        ...add.map((file, i) => write(file, `new-${ids[i]}\nこんにちは`)),
+        ...bin.map((file, i) => write(file, new Uint8Array([9, i, 8, i % 251]))),
+        ...del.map((file) => rm(file)),
+      ],
+      { concurrency: "unbounded" },
+    )
+    const after = yield* snapshot.track()
+    expect(after).toBeTruthy()
+    const diffs = yield* snapshot.diffFull(before!, after!)
+    expect(diffs).toHaveLength(ids.length * 4)
+    const map = new Map(diffs.map((item) => [item.file, item]))
+    for (let i = 0; i < ids.length; i++) {
+      const m = map.get(fwd("mix", `${ids[i]}-mod.txt`))
+      expect(m).toBeDefined()
+      expect(m!.patch).toContain(`-before-${ids[i]}-é`)
+      expect(m!.patch).toContain(`+after-${ids[i]}-é`)
+      expect(m!.status).toBe("modified")
+      const d = map.get(fwd("mix", `${ids[i]}-del.txt`))
+      expect(d).toBeDefined()
+      expect(d!.patch).toContain(`-gone-${ids[i]}`)
+      expect(d!.status).toBe("deleted")
+      const a = map.get(fwd("mix", `${ids[i]}-add.txt`))
+      expect(a).toBeDefined()
+      expect(a!.patch).toContain(`+new-${ids[i]}`)
+      expect(a!.status).toBe("added")
+      const b = map.get(fwd("mix", `${ids[i]}-bin.bin`))
+      expect(b).toBeDefined()
+      expect(b!.patch).toBe("")
+      expect(b!.additions).toBe(0)
+      expect(b!.deletions).toBe(0)
+      expect(b!.status).toBe("modified")
+    }
+  }),
+  { git: true },
+)
+
+it.instance(
+  "diffFull preserves git diff order across batch boundaries",
+  Effect.gen(function* () {
+    const tmp = yield* bootstrap()
+    const snapshot = yield* Snapshot.Service
+    const ids = Array.from({ length: 140 }, (_, i) => i.toString().padStart(3, "0"))
+    yield* mkdirp(`${tmp.path}/order`)
+    yield* Effect.all(
+      ids.map((id) => write(`${tmp.path}/order/${id}.txt`, `before-${id}`)),
+      { concurrency: "unbounded" },
+    )
+    const before = yield* snapshot.track()
+    expect(before).toBeTruthy()
+    yield* Effect.all(
+      ids.map((id) => write(`${tmp.path}/order/${id}.txt`, `after-${id}`)),
+      { concurrency: "unbounded" },
+    )
+    const after = yield* snapshot.track()
+    expect(after).toBeTruthy()
+    expect((yield* snapshot.diffFull(before!, after!)).map((item) => item.file)).toEqual(
+      ids.map((id) => `order/${id}.txt`),
+    )
+  }),
+  { git: true },
+)
+
+it.instance(
+  "diffFull with file modifications",
+  withTrackedSnapshot(({ tmp, snapshot, before }) =>
+    Effect.gen(function* () {
+      yield* write(`${tmp.path}/b.txt`, "modified content")
+      const after = yield* snapshot.track()
       expect(after).toBeTruthy()
-
-      const diffs = await run(tmp.path, (snapshot) => snapshot.diffFull(before!, after!))
+      const diffs = yield* snapshot.diffFull(before, after!)
       expect(diffs.length).toBe(1)
-
-      const modifiedFileDiff = diffs[0]
-      expect(modifiedFileDiff.file).toBe("b.txt")
-      expect(modifiedFileDiff.patch).toContain(`-${tmp.extra.bContent}`)
-      expect(modifiedFileDiff.patch).toContain("+modified content")
-      expect(modifiedFileDiff.additions).toBeGreaterThan(0)
-      expect(modifiedFileDiff.deletions).toBeGreaterThan(0)
-    },
-  })
-})
-
-test("diffFull with file deletions", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      const before = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(before).toBeTruthy()
-
-      await $`rm ${tmp.path}/a.txt`.quiet()
-
-      const after = await run(tmp.path, (snapshot) => snapshot.track())
+      expect(diffs[0].file).toBe("b.txt")
+      expect(diffs[0].patch).toContain(`-${tmp.extra.bContent}`)
+      expect(diffs[0].patch).toContain("+modified content")
+      expect(diffs[0].additions).toBeGreaterThan(0)
+      expect(diffs[0].deletions).toBeGreaterThan(0)
+    }),
+  ),
+  { git: true },
+)
+
+it.instance(
+  "diffFull with file deletions",
+  withTrackedSnapshot(({ tmp, snapshot, before }) =>
+    Effect.gen(function* () {
+      yield* rm(`${tmp.path}/a.txt`)
+      const after = yield* snapshot.track()
       expect(after).toBeTruthy()
-
-      const diffs = await run(tmp.path, (snapshot) => snapshot.diffFull(before!, after!))
+      const diffs = yield* snapshot.diffFull(before, after!)
       expect(diffs.length).toBe(1)
-
-      const removedFileDiff = diffs[0]
-      expect(removedFileDiff.file).toBe("a.txt")
-      expect(removedFileDiff.patch).toContain(`-${tmp.extra.aContent}`)
-      expect(removedFileDiff.additions).toBe(0)
-      expect(removedFileDiff.deletions).toBe(1)
-    },
-  })
-})
-
-test("diffFull with multiple line additions", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      const before = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(before).toBeTruthy()
-
-      await Filesystem.write(`${tmp.path}/multi.txt`, "line1\nline2\nline3")
-
-      const after = await run(tmp.path, (snapshot) => snapshot.track())
+      expect(diffs[0].file).toBe("a.txt")
+      expect(diffs[0].patch).toContain(`-${tmp.extra.aContent}`)
+      expect(diffs[0].additions).toBe(0)
+      expect(diffs[0].deletions).toBe(1)
+    }),
+  ),
+  { git: true },
+)
+
+it.instance(
+  "diffFull with multiple line additions",
+  withTrackedSnapshot(({ tmp, snapshot, before }) =>
+    Effect.gen(function* () {
+      yield* write(`${tmp.path}/multi.txt`, "line1\nline2\nline3")
+      const after = yield* snapshot.track()
       expect(after).toBeTruthy()
-
-      const diffs = await run(tmp.path, (snapshot) => snapshot.diffFull(before!, after!))
+      const diffs = yield* snapshot.diffFull(before, after!)
       expect(diffs.length).toBe(1)
-
-      const multiDiff = diffs[0]
-      expect(multiDiff.file).toBe("multi.txt")
-      expect(multiDiff.patch).toContain("+line1")
-      expect(multiDiff.patch).toContain("+line3")
-      expect(multiDiff.additions).toBe(3)
-      expect(multiDiff.deletions).toBe(0)
-    },
-  })
-})
-
-test("diffFull with addition and deletion", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      const before = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(before).toBeTruthy()
-
-      await Filesystem.write(`${tmp.path}/added.txt`, "added content")
-      await $`rm ${tmp.path}/a.txt`.quiet()
-
-      const after = await run(tmp.path, (snapshot) => snapshot.track())
+      expect(diffs[0].file).toBe("multi.txt")
+      expect(diffs[0].patch).toContain("+line1")
+      expect(diffs[0].patch).toContain("+line3")
+      expect(diffs[0].additions).toBe(3)
+      expect(diffs[0].deletions).toBe(0)
+    }),
+  ),
+  { git: true },
+)
+
+it.instance(
+  "diffFull with addition and deletion",
+  withTrackedSnapshot(({ tmp, snapshot, before }) =>
+    Effect.gen(function* () {
+      yield* write(`${tmp.path}/added.txt`, "added content")
+      yield* rm(`${tmp.path}/a.txt`)
+      const after = yield* snapshot.track()
       expect(after).toBeTruthy()
-
-      const diffs = await run(tmp.path, (snapshot) => snapshot.diffFull(before!, after!))
+      const diffs = yield* snapshot.diffFull(before, after!)
       expect(diffs.length).toBe(2)
-
-      const addedFileDiff = diffs.find((d) => d.file === "added.txt")
-      expect(addedFileDiff).toBeDefined()
-      expect(addedFileDiff!.patch).toContain("+added content")
-      expect(addedFileDiff!.additions).toBe(1)
-      expect(addedFileDiff!.deletions).toBe(0)
-
-      const removedFileDiff = diffs.find((d) => d.file === "a.txt")
-      expect(removedFileDiff).toBeDefined()
-      expect(removedFileDiff!.patch).toContain(`-${tmp.extra.aContent}`)
-      expect(removedFileDiff!.additions).toBe(0)
-      expect(removedFileDiff!.deletions).toBe(1)
-    },
-  })
-})
-
-test("diffFull with multiple additions and deletions", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      const before = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(before).toBeTruthy()
-
-      await Filesystem.write(`${tmp.path}/multi1.txt`, "line1\nline2\nline3")
-      await Filesystem.write(`${tmp.path}/multi2.txt`, "single line")
-      await $`rm ${tmp.path}/a.txt`.quiet()
-      await $`rm ${tmp.path}/b.txt`.quiet()
-
-      const after = await run(tmp.path, (snapshot) => snapshot.track())
+      const added = diffs.find((d) => d.file === "added.txt")!
+      expect(added.patch).toContain("+added content")
+      expect(added.additions).toBe(1)
+      expect(added.deletions).toBe(0)
+      const removed = diffs.find((d) => d.file === "a.txt")!
+      expect(removed.patch).toContain(`-${tmp.extra.aContent}`)
+      expect(removed.additions).toBe(0)
+      expect(removed.deletions).toBe(1)
+    }),
+  ),
+  { git: true },
+)
+
+it.instance(
+  "diffFull with multiple additions and deletions",
+  withTrackedSnapshot(({ tmp, snapshot, before }) =>
+    Effect.gen(function* () {
+      yield* write(`${tmp.path}/multi1.txt`, "line1\nline2\nline3")
+      yield* write(`${tmp.path}/multi2.txt`, "single line")
+      yield* rm(`${tmp.path}/a.txt`)
+      yield* rm(`${tmp.path}/b.txt`)
+      const after = yield* snapshot.track()
       expect(after).toBeTruthy()
-
-      const diffs = await run(tmp.path, (snapshot) => snapshot.diffFull(before!, after!))
+      const diffs = yield* snapshot.diffFull(before, after!)
       expect(diffs.length).toBe(4)
-
-      const multi1Diff = diffs.find((d) => d.file === "multi1.txt")
-      expect(multi1Diff).toBeDefined()
-      expect(multi1Diff!.additions).toBe(3)
-      expect(multi1Diff!.deletions).toBe(0)
-
-      const multi2Diff = diffs.find((d) => d.file === "multi2.txt")
-      expect(multi2Diff).toBeDefined()
-      expect(multi2Diff!.additions).toBe(1)
-      expect(multi2Diff!.deletions).toBe(0)
-
-      const removedADiff = diffs.find((d) => d.file === "a.txt")
-      expect(removedADiff).toBeDefined()
-      expect(removedADiff!.additions).toBe(0)
-      expect(removedADiff!.deletions).toBe(1)
-
-      const removedBDiff = diffs.find((d) => d.file === "b.txt")
-      expect(removedBDiff).toBeDefined()
-      expect(removedBDiff!.additions).toBe(0)
-      expect(removedBDiff!.deletions).toBe(1)
-    },
-  })
-})
-
-test("diffFull with no changes", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      const before = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(before).toBeTruthy()
-
-      const after = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(after).toBeTruthy()
-
-      const diffs = await run(tmp.path, (snapshot) => snapshot.diffFull(before!, after!))
-      expect(diffs.length).toBe(0)
-    },
-  })
-})
-
-test("diffFull with binary file changes", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      const before = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(before).toBeTruthy()
-
-      await Filesystem.write(`${tmp.path}/binary.bin`, new Uint8Array([0x00, 0x01, 0x02, 0x03]))
-
-      const after = await run(tmp.path, (snapshot) => snapshot.track())
+      expect(diffs.find((d) => d.file === "multi1.txt")!.additions).toBe(3)
+      expect(diffs.find((d) => d.file === "multi1.txt")!.deletions).toBe(0)
+      expect(diffs.find((d) => d.file === "multi2.txt")!.additions).toBe(1)
+      expect(diffs.find((d) => d.file === "multi2.txt")!.deletions).toBe(0)
+      expect(diffs.find((d) => d.file === "a.txt")!.additions).toBe(0)
+      expect(diffs.find((d) => d.file === "a.txt")!.deletions).toBe(1)
+      expect(diffs.find((d) => d.file === "b.txt")!.additions).toBe(0)
+      expect(diffs.find((d) => d.file === "b.txt")!.deletions).toBe(1)
+    }),
+  ),
+  { git: true },
+)
+
+it.instance(
+  "diffFull with no changes",
+  withTrackedSnapshot(({ snapshot, before }) =>
+    Effect.gen(function* () {
+      const after = yield* snapshot.track()
       expect(after).toBeTruthy()
-
-      const diffs = await run(tmp.path, (snapshot) => snapshot.diffFull(before!, after!))
-      expect(diffs.length).toBe(1)
-
-      const binaryDiff = diffs[0]
-      expect(binaryDiff.file).toBe("binary.bin")
-      expect(binaryDiff.patch).toBe("")
-    },
-  })
-})
-
-test("diffFull with whitespace changes", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      await Filesystem.write(`${tmp.path}/whitespace.txt`, "line1\nline2")
-      const before = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(before).toBeTruthy()
-
-      await Filesystem.write(`${tmp.path}/whitespace.txt`, "line1\n\nline2\n")
-
-      const after = await run(tmp.path, (snapshot) => snapshot.track())
+      expect((yield* snapshot.diffFull(before, after!)).length).toBe(0)
+    }),
+  ),
+  { git: true },
+)
+
+it.instance(
+  "diffFull with binary file changes",
+  withTrackedSnapshot(({ tmp, snapshot, before }) =>
+    Effect.gen(function* () {
+      yield* write(`${tmp.path}/binary.bin`, new Uint8Array([0x00, 0x01, 0x02, 0x03]))
+      const after = yield* snapshot.track()
       expect(after).toBeTruthy()
-
-      const diffs = await run(tmp.path, (snapshot) => snapshot.diffFull(before!, after!))
+      const diffs = yield* snapshot.diffFull(before, after!)
       expect(diffs.length).toBe(1)
-
-      const whitespaceDiff = diffs[0]
-      expect(whitespaceDiff.file).toBe("whitespace.txt")
-      expect(whitespaceDiff.additions).toBeGreaterThan(0)
-    },
-  })
-})
-
-test("revert with overlapping files across patches uses first patch hash", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      // Write initial content and snapshot
-      await Filesystem.write(`${tmp.path}/shared.txt`, "v1")
-      const snap1 = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(snap1).toBeTruthy()
-
-      // Modify and snapshot again
-      await Filesystem.write(`${tmp.path}/shared.txt`, "v2")
-      const snap2 = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(snap2).toBeTruthy()
-
-      // Modify once more so both patches include shared.txt
-      await Filesystem.write(`${tmp.path}/shared.txt`, "v3")
-
-      const patch1 = await run(tmp.path, (snapshot) => snapshot.patch(snap1!))
-      const patch2 = await run(tmp.path, (snapshot) => snapshot.patch(snap2!))
-
-      // Both patches should include shared.txt
-      expect(patch1.files).toContain(fwd(tmp.path, "shared.txt"))
-      expect(patch2.files).toContain(fwd(tmp.path, "shared.txt"))
-
-      // Revert with patch1 first — should use snap1's hash (restoring "v1")
-      await run(tmp.path, (snapshot) => snapshot.revert([patch1, patch2]))
-
-      const content = await fs.readFile(`${tmp.path}/shared.txt`, "utf-8")
-      expect(content).toBe("v1")
-    },
-  })
-})
-
-test("revert preserves patch order when the same hash appears again", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      await $`mkdir -p ${tmp.path}/foo`.quiet()
-      await Filesystem.write(`${tmp.path}/foo/bar`, "v1")
-      await Filesystem.write(`${tmp.path}/a.txt`, "v1")
-
-      const snap1 = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(snap1).toBeTruthy()
-
-      await $`rm -rf ${tmp.path}/foo`.quiet()
-      await Filesystem.write(`${tmp.path}/foo`, "v2")
-      await Filesystem.write(`${tmp.path}/a.txt`, "v2")
-
-      const snap2 = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(snap2).toBeTruthy()
-
-      await $`rm -rf ${tmp.path}/foo`.quiet()
-      await Filesystem.write(`${tmp.path}/a.txt`, "v3")
-
-      await run(tmp.path, (snapshot) =>
-        snapshot.revert([
-          { hash: snap1!, files: [fwd(tmp.path, "a.txt")] },
-          { hash: snap2!, files: [fwd(tmp.path, "foo")] },
-          { hash: snap1!, files: [fwd(tmp.path, "foo", "bar")] },
-        ]),
-      )
-
-      expect(await fs.readFile(`${tmp.path}/a.txt`, "utf-8")).toBe("v1")
-      expect((await fs.stat(`${tmp.path}/foo`)).isDirectory()).toBe(true)
-      expect(await fs.readFile(`${tmp.path}/foo/bar`, "utf-8")).toBe("v1")
-    },
-  })
-})
-
-test("revert handles large mixed batches across chunk boundaries", async () => {
-  await using tmp = await bootstrap()
-  await WithInstance.provide({
-    directory: tmp.path,
-    fn: async () => {
-      const base = Array.from({ length: 140 }, (_, i) => fwd(tmp.path, "batch", `${i}.txt`))
-      const fresh = Array.from({ length: 140 }, (_, i) => fwd(tmp.path, "fresh", `${i}.txt`))
-
-      await $`mkdir -p ${tmp.path}/batch ${tmp.path}/fresh`.quiet()
-      await Promise.all(base.map((file, i) => Filesystem.write(file, `base-${i}`)))
-
-      const snap = await run(tmp.path, (snapshot) => snapshot.track())
-      expect(snap).toBeTruthy()
-
-      await Promise.all(base.map((file, i) => Filesystem.write(file, `next-${i}`)))
-      await Promise.all(fresh.map((file, i) => Filesystem.write(file, `fresh-${i}`)))
-
-      const patch = await run(tmp.path, (snapshot) => snapshot.patch(snap!))
-      expect(patch.files.length).toBe(base.length + fresh.length)
-
-      await run(tmp.path, (snapshot) => snapshot.revert([patch]))
-
-      await Promise.all(
-        base.map(async (file, i) => {
-          expect(await fs.readFile(file, "utf-8")).toBe(`base-${i}`)
-        }),
-      )
-
-      await Promise.all(
-        fresh.map(async (file) => {
-          expect(
-            await fs
-              .access(file)
-              .then(() => true)
-              .catch(() => false),
-          ).toBe(false)
-        }),
-      )
-    },
-  })
-})
+      expect(diffs[0].file).toBe("binary.bin")
+      expect(diffs[0].patch).toBe("")
+    }),
+  ),
+  { git: true },
+)
+
+it.instance(
+  "diffFull with whitespace changes",
+  Effect.gen(function* () {
+    const tmp = yield* bootstrap()
+    const snapshot = yield* Snapshot.Service
+    yield* write(`${tmp.path}/whitespace.txt`, "line1\nline2")
+    const before = yield* snapshot.track()
+    expect(before).toBeTruthy()
+    yield* write(`${tmp.path}/whitespace.txt`, "line1\n\nline2\n")
+    const after = yield* snapshot.track()
+    expect(after).toBeTruthy()
+    const diffs = yield* snapshot.diffFull(before!, after!)
+    expect(diffs.length).toBe(1)
+    expect(diffs[0].file).toBe("whitespace.txt")
+    expect(diffs[0].additions).toBeGreaterThan(0)
+  }),
+  { git: true },
+)
+
+it.instance(
+  "revert with overlapping files across patches uses first patch hash",
+  Effect.gen(function* () {
+    const tmp = yield* bootstrap()
+    const snapshot = yield* Snapshot.Service
+    yield* write(`${tmp.path}/shared.txt`, "v1")
+    const snap1 = yield* snapshot.track()
+    expect(snap1).toBeTruthy()
+    yield* write(`${tmp.path}/shared.txt`, "v2")
+    const snap2 = yield* snapshot.track()
+    expect(snap2).toBeTruthy()
+    yield* write(`${tmp.path}/shared.txt`, "v3")
+    const patch1 = yield* snapshot.patch(snap1!)
+    const patch2 = yield* snapshot.patch(snap2!)
+    expect(patch1.files).toContain(fwd(tmp.path, "shared.txt"))
+    expect(patch2.files).toContain(fwd(tmp.path, "shared.txt"))
+    yield* snapshot.revert([patch1, patch2])
+    expect(yield* readText(`${tmp.path}/shared.txt`)).toBe("v1")
+  }),
+  { git: true },
+)
+
+it.instance(
+  "revert preserves patch order when the same hash appears again",
+  Effect.gen(function* () {
+    const tmp = yield* bootstrap()
+    const snapshot = yield* Snapshot.Service
+    yield* mkdirp(`${tmp.path}/foo`)
+    yield* write(`${tmp.path}/foo/bar`, "v1")
+    yield* write(`${tmp.path}/a.txt`, "v1")
+    const snap1 = yield* snapshot.track()
+    expect(snap1).toBeTruthy()
+    yield* rm(`${tmp.path}/foo`)
+    yield* write(`${tmp.path}/foo`, "v2")
+    yield* write(`${tmp.path}/a.txt`, "v2")
+    const snap2 = yield* snapshot.track()
+    expect(snap2).toBeTruthy()
+    yield* rm(`${tmp.path}/foo`)
+    yield* write(`${tmp.path}/a.txt`, "v3")
+    yield* snapshot.revert([
+      { hash: snap1!, files: [fwd(tmp.path, "a.txt")] },
+      { hash: snap2!, files: [fwd(tmp.path, "foo")] },
+      { hash: snap1!, files: [fwd(tmp.path, "foo", "bar")] },
+    ])
+    expect(yield* readText(`${tmp.path}/a.txt`)).toBe("v1")
+    expect((yield* Effect.promise(() => fs.stat(`${tmp.path}/foo`))).isDirectory()).toBe(true)
+    expect(yield* readText(`${tmp.path}/foo/bar`)).toBe("v1")
+  }),
+  { git: true },
+)
+
+it.instance(
+  "revert handles large mixed batches across chunk boundaries",
+  Effect.gen(function* () {
+    const tmp = yield* bootstrap()
+    const snapshot = yield* Snapshot.Service
+    const base = Array.from({ length: 140 }, (_, i) => fwd(tmp.path, "batch", `${i}.txt`))
+    const fresh = Array.from({ length: 140 }, (_, i) => fwd(tmp.path, "fresh", `${i}.txt`))
+    yield* mkdirp(`${tmp.path}/batch`)
+    yield* mkdirp(`${tmp.path}/fresh`)
+    yield* Effect.all(
+      base.map((file, i) => write(file, `base-${i}`)),
+      { concurrency: "unbounded" },
+    )
+    const snap = yield* snapshot.track()
+    expect(snap).toBeTruthy()
+    yield* Effect.all(
+      [...base.map((file, i) => write(file, `next-${i}`)), ...fresh.map((file, i) => write(file, `fresh-${i}`))],
+      { concurrency: "unbounded" },
+    )
+    const patch = yield* snapshot.patch(snap!)
+    expect(patch.files.length).toBe(base.length + fresh.length)
+    yield* snapshot.revert([patch])
+    for (let i = 0; i < base.length; i++) expect(yield* readText(base[i])).toBe(`base-${i}`)
+    for (const file of fresh) expect(yield* exists(file)).toBe(false)
+  }),
+  { git: true },
+)