fix(core): if git hash-object reports fewer hashes than requested - l…

…og one of the missing files

When executing parallel targets using e.g. run-commands missing entries in .gitignore
may lead to
temp files being passed to "git hash-object"
which when git executes have been deleted
resulting in
mismatch between number of files requested and hashes returned.
git reports the error and this PR
will make sure that report is passed
in the error thrown.
This will make problem resolution a lot
faster.

ISSUES CLOSED: nrwl#9946

packages/nx/src/hasher/git-hasher.spec.ts

@@ -1,7 +1,7 @@
-import { dirSync } from 'tmp';
-import { mkdirSync, removeSync } from 'fs-extra';
 import { execSync } from 'child_process';
-import { getFileHashes } from './git-hasher';
+import { mkdirSync, removeSync } from 'fs-extra';
+import { dirSync } from 'tmp';
+import { getFileHashes, getGitHashForBatch } from './git-hasher';
 
 describe('git-hasher', () => {
   let dir: string;
@@ -173,4 +173,27 @@ describe('git-hasher', () => {
   function run(command: string) {
     return execSync(command, { cwd: dir, stdio: ['pipe', 'pipe', 'pipe'] });
   }
+
+  it('should hash two simple files', async () => {
+    const files = ['a.txt', 'b.txt'];
+    run(`echo AAA > a.txt`);
+    run(`echo BBB > b.txt`);
+    const hashes = await getGitHashForBatch(files, dir);
+    expect([...hashes.keys()]).toEqual(files);
+  });
+
+  it('should fail when file deleted', async () => {
+    const files = ['a.txt', 'b.txt'];
+    run(`echo AAA > a.txt`);
+    try {
+      const hashes = await getGitHashForBatch(files, dir);
+      expect(false).toBeTruthy();
+    } catch (err: any) {
+      expect(err instanceof Error).toBeTruthy();
+      const error = err as Error;
+      expect(error.message).toEqual(
+        "Passed 2 file paths to Git to hash, but received 1 hashes.\nfatal: Cannot open 'b.txt': No such file or directory\n"
+      );
+    }
+  });
 });

packages/nx/src/hasher/git-hasher.ts

@@ -40,17 +40,17 @@ export async function getGitHashForFiles(
   return { hashes: res, deleted };
 }
 
-async function getGitHashForBatch(filesToHash: string[], path) {
+export async function getGitHashForBatch(filesToHash: string[], path) {
   const res: Map<string, string> = new Map<string, string>();
-  const hashStdout = await spawnProcess(
+  const { stdout: hashStdout, stderr: hashStderr } = await spawnProcess(
     'git',
     ['hash-object', ...filesToHash],
     path
   );
   const hashes: string[] = hashStdout.split('\n').filter((s) => !!s);
   if (hashes.length !== filesToHash.length) {
     throw new Error(
-      `Passed ${filesToHash.length} file paths to Git to hash, but received ${hashes.length} hashes.`
+      `Passed ${filesToHash.length} file paths to Git to hash, but received ${hashes.length} hashes.\n${hashStderr}`
     );
   }
   for (let i = 0; i < hashes.length; i++) {
@@ -67,7 +67,7 @@ function getActualFilesToHash(
 ): { filesToHash: string[]; deleted: string[] } {
   const filesToHash = [];
   const deleted = [];
-  for (let file of potentialFilesToHash) {
+  for (const file of potentialFilesToHash) {
     if (fileExists(joinPathFragments(path, file))) {
       filesToHash.push(file);
     } else {
@@ -77,28 +77,42 @@ function getActualFilesToHash(
   return { filesToHash, deleted };
 }
 
-async function spawnProcess(command: string, args: string[], cwd: string) {
+async function spawnProcess(
+  command: string,
+  args: string[],
+  cwd: string
+): Promise<{ code: number; stdout: string; stderr: string }> {
   const cp = spawn(command, args, {
     windowsHide: true,
     shell: false,
     cwd,
   });
   let stdout = '';
-  for await (const data of cp.stdout) {
+  let stderr = '';
+  cp.stdout.on('data', (data) => {
     stdout += data;
-  }
-  return stdout;
+  });
+  cp.stderr.on('data', (data) => {
+    stderr += data;
+  });
+  return new Promise((resolve) => {
+    cp.on('close', (code) => {
+      resolve({ code, stdout, stderr });
+    });
+  });
 }
 
 async function getStagedFiles(path: string) {
-  const staged = await spawnProcess(
+  const { stdout: staged } = await spawnProcess(
     'git',
     ['ls-files', '-s', '-z', '--exclude-standard', '.'],
     path
   );
   const res = new Map();
-  for (let line of staged.split('\0')) {
-    if (!line) continue;
+  for (const line of staged.split('\0')) {
+    if (!line) {
+      continue;
+    }
     const [_, hash, __, ...fileParts] = line.split(/\s/);
     const fileName = fileParts.join(' ');
     res.set(fileName, hash);
@@ -107,7 +121,7 @@ async function getStagedFiles(path: string) {
 }
 
 async function getUnstagedFiles(path: string) {
-  const unstaged = await spawnProcess(
+  const { stdout: unstaged } = await spawnProcess(
     'git',
     ['ls-files', '-m', '-z', '--exclude-standard', '.'],
     path
@@ -117,7 +131,7 @@ async function getUnstagedFiles(path: string) {
 }
 
 async function getUntrackedFiles(path: string) {
-  const untracked = await spawnProcess(
+  const { stdout: untracked } = await spawnProcess(
     'git',
     ['ls-files', '--other', '-z', '--exclude-standard', '.'],
     path