fix(coding-agent/utils): handled EISDIR and ENOTDIR errors during ref resolution

- Update `shouldRetry` to treat `EISDIR` and `ENOTDIR` as terminal errors, preventing unnecessary retries when encountering Git reference directory conflicts.
- Add a test suite to verify graceful resolution of branches in scenarios where a packed ref conflicts with a directory path in the filesystem.

packages/coding-agent/src/utils/git.ts

@@ -1,7 +1,7 @@
 import * as fs from "node:fs";
 import * as os from "node:os";
 import * as path from "node:path";
-import { $which, hasFsCode, isEnoent, Snowflake } from "@oh-my-pi/pi-utils";
+import { $which, hasFsCode, isEisdir, isEnoent, isEnotdir, Snowflake } from "@oh-my-pi/pi-utils";
 import {
 	parseDiffHunks as parseCommitDiffHunks,
 	parseFileDiffs,
@@ -376,7 +376,8 @@ async function writeTempPatch(content: string): Promise<string> {
 type EntryType = "directory" | "file";
 
 function shouldRetry(err: unknown, n: number) {
-	if (isEnoent(err) || hasFsCode(err, "ENFILE") || hasFsCode(err, "EMFILE")) return false;
+	if (isEnoent(err) || isEisdir(err) || isEnotdir(err) || hasFsCode(err, "ENFILE") || hasFsCode(err, "EMFILE"))
+		return false;
 	if (hasFsCode(err, "EINTR")) return n < EINTR_MAX_RETRIES;
 	if (n > EINTR_MAX_RETRIES) throw err;
 	throw err;

packages/coding-agent/test/utils/git-eisdir-fallback.test.ts

@@ -0,0 +1,70 @@
+import { afterAll, beforeAll, describe, expect, test } from "bun:test";
+import * as fs from "node:fs/promises";
+import * as os from "node:os";
+import * as path from "node:path";
+import { $ } from "bun";
+import * as git from "../../src/utils/git";
+
+describe("git reference directory fallback", () => {
+	let repoDir: string;
+	let commitSha: string;
+
+	beforeAll(async () => {
+		repoDir = await fs.mkdtemp(path.join(os.tmpdir(), "omp-ref-fallback-"));
+		const initResult = await $`git init --initial-branch=main`.cwd(repoDir).quiet();
+		if (initResult.exitCode !== 0) throw new Error("git init failed");
+		await $`git config user.name "Test User"`.cwd(repoDir).quiet();
+		await $`git config user.email "test@example.com"`.cwd(repoDir).quiet();
+		await fs.writeFile(path.join(repoDir, "file.txt"), "hello world");
+		await $`git add file.txt`.cwd(repoDir).quiet();
+		await $`git commit -m "initial commit"`.cwd(repoDir).quiet();
+
+		commitSha = (await $`git rev-parse HEAD`.cwd(repoDir).quiet().text()).trim();
+
+		// We will simulate a situation where:
+		// There is a branch called "pi-flash" which is packed (in packed-refs).
+		// But there is also a subdirectory created inside refs/heads under the same name:
+		// refs/heads/pi-flash/... because a branch called "pi-flash/something" exists as a loose ref.
+		// Thus:
+		// 1. refs/heads/pi-flash is a directory on disk.
+		// 2. packed-refs contains: <commitSha> refs/heads/pi-flash
+		// In this case, trying to read refs/heads/pi-flash as a file throws EISDIR.
+		// We want to verify that we gracefully handle this and fallback to resolving from packed-refs.
+
+		// Let's pack the current main branch as refs/heads/pi-flash so we have it in packed-refs
+		await $`git update-ref refs/heads/pi-flash ${commitSha}`.cwd(repoDir).quiet();
+		// Also point HEAD to refs/heads/pi-flash so we exercise HEAD -> ref -> readRef / readRefSync
+		await fs.writeFile(path.join(repoDir, ".git", "HEAD"), "ref: refs/heads/pi-flash\n");
+		await $`git pack-refs --all`.cwd(repoDir).quiet();
+		// Check that packed-refs exists
+		const packedRefs = await fs.readFile(path.join(repoDir, ".git", "packed-refs"), "utf8");
+		expect(packedRefs).toContain("refs/heads/pi-flash");
+
+		// Delete the loose ref file for refs/heads/pi-flash if git pack-refs didn't already delete it (it usually does).
+		await fs.rm(path.join(repoDir, ".git", "refs", "heads", "pi-flash"), { force: true });
+
+		// Now, create refs/heads/pi-flash as a directory to simulate another branch like "pi-flash/feature" existing.
+		// We can just create the directory and a file inside it, or just the directory.
+		await fs.mkdir(path.join(repoDir, ".git", "refs", "heads", "pi-flash"), { recursive: true });
+		await fs.writeFile(path.join(repoDir, ".git", "refs", "heads", "pi-flash", "feature"), commitSha);
+	});
+
+	afterAll(async () => {
+		await fs.rm(repoDir, { recursive: true, force: true }).catch(() => {});
+	});
+
+	test("resolves branch that has directory conflict via resolveSync on head", () => {
+		const headStateSync = git.head.resolveSync(repoDir);
+		expect(headStateSync).not.toBeNull();
+		if (!headStateSync) return;
+		expect(headStateSync.commit).toBe(commitSha);
+	});
+
+	test("resolves branch that has directory conflict via resolve on ref", async () => {
+		const repository = await git.repo.resolve(repoDir);
+		expect(repository).not.toBeNull();
+		if (!repository) return;
+		const resolved = await git.ref.resolve(repoDir, "refs/heads/pi-flash");
+		expect(resolved).toBe(commitSha);
+	});
+});