fix(git): return checkout diff hunks from subdirectory workspaces

Checkout paths are repository-relative, but one-shot diff reads used the workspace subdirectory for Git pathspecs. Resolve the worktree root once so patch selection and file reads use the same coordinates as the live subscription.

packages/server/package.json

@@ -89,7 +89,7 @@
     "speech:transcribe:local": "tsx scripts/transcribe-local-wav.ts",
     "test": "npm run test:unit && npm run test:integration",
     "test:unit": "vitest run --fileParallelism --exclude \"**/*.e2e.test.ts\"",
-    "test:integration": "vitest run --maxWorkers=1 src/server/git-filename-diffs.e2e.test.ts src/server/daemon-e2e/filesystem.e2e.test.ts src/server/daemon-e2e/file-download.e2e.test.ts src/server/daemon-e2e/cli-logs-follow.e2e.test.ts src/server/creation/creation.e2e.test.ts src/server/daemon-e2e/terminal-workspace-sdk.e2e.test.ts src/server/daemon-e2e/models.e2e.test.ts src/server/daemon-e2e/live-preferences.e2e.test.ts src/server/daemon-e2e/oversized-message.e2e.test.ts src/server/agent/model-catalog.e2e.test.ts src/server/plugins/plugin-paseo-api.e2e.test.ts && vitest run --maxWorkers=1 src/server/daemon-e2e/git-operations.e2e.test.ts -t \"merges into\" && vitest run --maxWorkers=1 src/server/session.create-agent-worktree-autoarchive.e2e.test.ts -t \"creates a worktree and auto-archives both\" && vitest run --maxWorkers=1 src/server/agent/providers/opencode-bridge.local.e2e.test.ts -t \"versioned runtime\" && vitest run --maxWorkers=1 src/server/daemon-e2e/relay-transport.e2e.test.ts -t \"oversized attachments\"",
+    "test:integration": "vitest run --maxWorkers=1 src/server/git-filename-diffs.e2e.test.ts src/server/daemon-e2e/checkout-diff-content.e2e.test.ts src/server/daemon-e2e/filesystem.e2e.test.ts src/server/daemon-e2e/file-download.e2e.test.ts src/server/daemon-e2e/cli-logs-follow.e2e.test.ts src/server/creation/creation.e2e.test.ts src/server/daemon-e2e/terminal-workspace-sdk.e2e.test.ts src/server/daemon-e2e/models.e2e.test.ts src/server/daemon-e2e/live-preferences.e2e.test.ts src/server/daemon-e2e/oversized-message.e2e.test.ts src/server/agent/model-catalog.e2e.test.ts src/server/plugins/plugin-paseo-api.e2e.test.ts && vitest run --maxWorkers=1 src/server/daemon-e2e/git-operations.e2e.test.ts -t \"merges into\" && vitest run --maxWorkers=1 src/server/session.create-agent-worktree-autoarchive.e2e.test.ts -t \"creates a worktree and auto-archives both\" && vitest run --maxWorkers=1 src/server/agent/providers/opencode-bridge.local.e2e.test.ts -t \"versioned runtime\" && vitest run --maxWorkers=1 src/server/daemon-e2e/relay-transport.e2e.test.ts -t \"oversized attachments\"",
     "test:hub-cli-contract": "vitest run --maxWorkers=1 src/server/hub/hub-cli-contract.test.ts",
     "test:integration:all": "npm run test:e2e",
     "test:integration:real": "vitest run real.e2e.test.ts",

packages/server/src/server/daemon-e2e/checkout-diff-content.e2e.test.ts

@@ -1,5 +1,5 @@
 import { execFileSync } from "node:child_process";
-import { mkdtempSync, rmSync, writeFileSync } from "node:fs";
+import { mkdirSync, mkdtempSync, rmSync, writeFileSync } from "node:fs";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
 import { expect, test } from "vitest";
@@ -85,3 +85,76 @@ test.each(["uncommitted", "base", "commit"] as const)(
   },
   60_000,
 );
+
+test.each(
+  (["uncommitted", "base"] as const).flatMap((mode) =>
+    (["single", "batch", "rename"] as const).map((shape) => ({ mode, shape })),
+  ),
+)(
+  "$mode $shape diff includes hunks from a repository subdirectory",
+  async ({ mode, shape }) => {
+    const ctx = await createDaemonTestContext();
+    const cwd = mkdtempSync(join(tmpdir(), "checkout-diff-subdirectory-"));
+
+    try {
+      git(cwd, "init", "-b", "main");
+      git(cwd, "config", "user.name", "Test");
+      git(cwd, "config", "user.email", "test@example.com");
+      git(cwd, "config", "core.autocrlf", "false");
+      const subdirectory = join(cwd, "sub");
+      mkdirSync(subdirectory);
+      const unchangedLines = "unchanged\n".repeat(10);
+      writeFileSync(join(subdirectory, "normal.txt"), `before\n${unchangedLines}`);
+      if (shape === "batch") {
+        writeFileSync(join(cwd, "sibling.txt"), "old sibling\n");
+      }
+      git(cwd, "add", ".");
+      git(cwd, "-c", "commit.gpgsign=false", "commit", "-m", "initial");
+      if (mode === "base") {
+        git(cwd, "checkout", "-b", "feature");
+      }
+      const filename = shape === "rename" ? "renamed.txt" : "normal.txt";
+      if (shape === "rename") {
+        git(cwd, "mv", "sub/normal.txt", `sub/${filename}`);
+      }
+      writeFileSync(join(subdirectory, filename), `after\n${unchangedLines}`);
+      if (shape === "batch") {
+        writeFileSync(join(cwd, "sibling.txt"), "new sibling\n");
+      }
+      if (mode === "base") {
+        git(cwd, "add", ".");
+        git(cwd, "-c", "commit.gpgsign=false", "commit", "-m", "edit");
+      }
+
+      const compare = { mode, baseRef: "main" };
+      const rootDiff = await ctx.client.getCheckoutDiff(cwd, compare);
+      const subdirectoryDiff = await ctx.client.getCheckoutDiff(subdirectory, compare);
+      const subscription = ctx.client.observeCheckoutDiff(subdirectory, compare);
+      const liveDiff = await subscription.ready;
+      await subscription.release();
+
+      expect(rootDiff.error).toBeNull();
+      expect(subdirectoryDiff.error).toBeNull();
+      expect(liveDiff.error).toBeNull();
+      expect(liveDiff.files).toEqual(rootDiff.files);
+      expect(rootDiff.files).toHaveLength(shape === "batch" ? 2 : 1);
+      const file = rootDiff.files.find((candidate) => candidate.path === `sub/${filename}`);
+      expect(file).toMatchObject({
+        additions: 1,
+        deletions: 1,
+        ...(shape === "rename" ? { oldPath: "sub/normal.txt" } : {}),
+      });
+      expect(file?.hunks.flatMap((hunk) => hunk.lines)).toEqual(
+        expect.arrayContaining([
+          expect.objectContaining({ type: "remove", content: "before" }),
+          expect.objectContaining({ type: "add", content: "after" }),
+        ]),
+      );
+      expect(subdirectoryDiff.files).toEqual(rootDiff.files);
+    } finally {
+      await ctx.cleanup();
+      rmSync(cwd, { recursive: true, force: true });
+    }
+  },
+  60_000,
+);

packages/server/src/utils/checkout-git.ts

@@ -3423,7 +3423,7 @@ export async function getCheckoutDiff(
   compare: CheckoutDiffCompare,
   context?: CheckoutContext,
 ): Promise<CheckoutDiffResult> {
-  await requireGitRepo(cwd);
+  cwd = await requireGitWorktreeRoot(cwd);
 
   const refsForDiff = await resolveCheckoutDiffRefs(cwd, compare, context);
   if (!refsForDiff) {