fix: include untracked files in diff patch for working-tree runs (#45)

* fix: include untracked files in diff patch for working-tree runs

* perf: parallelize untracked file diff generation

Author: dastratakos

packages/cli/src/git.ts

@@ -146,7 +146,7 @@ export function getUntrackedFiles(): string[] {
 	return out ? out.split("\n") : [];
 }
 
-function hasStringStdout(err: unknown): err is { stdout: string } {
+export function hasStringStdout(err: unknown): err is { stdout: string } {
 	return (
 		typeof err === "object" && err !== null && "stdout" in err && typeof err.stdout === "string"
 	);

packages/cli/src/routes/diff.ts

@@ -7,14 +7,49 @@ import { eq } from "drizzle-orm";
 import type { StageDb } from "../db/client.js";
 import type { ChapterRunRow } from "../db/schema/chapter-run.js";
 import { chapterRun } from "../db/schema/index.js";
-import { buildDiffArgs } from "../git.js";
+import { buildDiffArgs, hasStringStdout } from "../git.js";
 import { SCOPE_KIND, WORKING_TREE_REF } from "../schema.js";
 import type { Route } from "../server.js";
 import { writeJson } from "./json.js";
 
 const execFileAsync = promisify(execFile);
 
 const MAX_FILE_BYTES = 5 * 1024 * 1024;
+const MAX_DIFF_BYTES = 50 * 1024 * 1024;
+
+async function buildUntrackedPatch(cwd: string): Promise<string> {
+	const { stdout } = await execFileAsync("git", ["ls-files", "--others", "--exclude-standard"], {
+		cwd,
+		encoding: "utf8",
+	});
+	const files = stdout.trim() ? stdout.trim().split("\n") : [];
+	if (files.length === 0) return "";
+
+	const patches = await Promise.all(
+		files.map(async (file) => {
+			try {
+				await execFileAsync(
+					"git",
+					[
+						"diff",
+						"--no-index",
+						"--no-color",
+						"--src-prefix=a/",
+						"--dst-prefix=b/",
+						"--",
+						"/dev/null",
+						file,
+					],
+					{ cwd, encoding: "utf8", maxBuffer: MAX_DIFF_BYTES },
+				);
+				return "";
+			} catch (err: unknown) {
+				return hasStringStdout(err) ? err.stdout : "";
+			}
+		}),
+	);
+	return patches.filter(Boolean).join("\n");
+}
 
 export function diffRoutes(db: StageDb): Route[] {
 	return [
@@ -47,11 +82,23 @@ export function diffRoutes(db: StageDb): Route[] {
 					run.scopeKind === SCOPE_KIND.COMMITTED ? "private, max-age=300" : "no-store";
 
 				try {
-					const { stdout: patch } = await execFileAsync("git", args, {
+					const { stdout: trackedPatch } = await execFileAsync("git", args, {
 						cwd: repoRoot,
 						encoding: "utf8",
-						maxBuffer: 50 * 1024 * 1024,
+						maxBuffer: MAX_DIFF_BYTES,
 					});
+
+					let patch = trackedPatch;
+					if (
+						run.scopeKind === SCOPE_KIND.WORKING_TREE &&
+						run.workingTreeRef === WORKING_TREE_REF.WORK
+					) {
+						const untrackedPatch = await buildUntrackedPatch(repoRoot);
+						if (untrackedPatch) {
+							patch = patch ? `${patch}\n${untrackedPatch}` : untrackedPatch;
+						}
+					}
+
 					const fileContents = await buildFileContents(run, repoRoot, patch);
 					const body: DiffResponse = { patch, fileContents };
 					res.writeHead(200, {