fix(snapshot): respect gitignore for previously tracked files (#22171)

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

@@ -511,6 +511,49 @@ test("circular symlinks", async () => {
   })
 })
 
+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 $`git commit -m init`.cwd(dir).quiet()
+    },
+  })
+
+  await Instance.provide({
+    directory: tmp.path,
+    fn: async () => {
+      const before = await Snapshot.track()
+      expect(before).toBeTruthy()
+
+      // Modify tracked files and create new ones - some ignored, some not
+      await Filesystem.write(`${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 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 Instance.provide({
@@ -535,6 +578,40 @@ test("gitignore changes", async () => {
   })
 })
 
+test("files tracked in snapshot but now gitignored are filtered out", async () => {
+  await using tmp = await bootstrap()
+  await Instance.provide({
+    directory: tmp.path,
+    fn: async () => {
+      // First, create a file and snapshot it
+      await Filesystem.write(`${tmp.path}/later-ignored.txt`, "initial content")
+      const before = await Snapshot.track()
+      expect(before).toBeTruthy()
+
+      // Modify the file (so it appears in diff-files)
+      await Filesystem.write(`${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 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("git info exclude changes", async () => {
   await using tmp = await bootstrap()
   await Instance.provide({