ensure-repo.ts fails before build when a file gets deleted

[krassowski]

The ensureBranch method checks files for stale references to wrong branch. When removing a file which is under version control jlpm run build will fail on that method with a message like:

> @jupyterlab/repo-top@0.0.1 build:dev
> npm run integrity && npm run build:all && cd dev_mode && npm run build


> @jupyterlab/repo-top@0.0.1 integrity
> node scripts/ensure-buildutils.js && node buildutils/lib/ensure-repo.js

Error: ENOENT: no such file or directory, open 'packages/some-package/src/some-file.ts'
    at Object.openSync (node:fs:600:3)
    at Object.readFileSync (node:fs:468:35)
    at ~/jupyterlab/buildutils/lib/ensure-repo.js:358:28
    at Array.forEach (<anonymous>)
    at ensureBranch (~/jupyterlab/buildutils/lib/ensure-repo.js:354:11)
    at ensureIntegrity (~/jupyterlab/buildutils/lib/ensure-repo.js:637:28)
    at Object.<anonymous> (~/jupyterlab/buildutils/lib/ensure-repo.js:817:10)
    at Module._compile (node:internal/modules/cjs/loader:1218:14)
    at Module._extensions..js (node:internal/modules/cjs/loader:1272:10)
    at Module.load (node:internal/modules/cjs/loader:1081:32) {
  errno: -2,
  syscall: 'open',
  code: 'ENOENT',
  path: 'packages/some-package/src/some-file.ts'
}

This is because until the removal is committed, the file will show up in the output of:

jupyterlab/buildutils/src/ensure-repo.ts

Lines 334 to 337 in ae54125

	let files = execSync('git ls-tree -r HEAD --name-only')
	.toString()
	.trim()
	.split(/\r?\n/);

and the script then attempts to load it with

jupyterlab/buildutils/src/ensure-repo.ts

Lines 355 to 360 in ae54125

	// Make the string replacements
	files.forEach(filePath => {
	if (path.basename(filePath) === 'ensure-repo.ts') {
	return;
	}
	const oldData = fs.readFileSync(filePath, 'utf-8');

Workaround

Commit the removal of the file

Future solution

We could either:

• adjust the command so that it does not show the deleted files (see https://stackoverflow.com/questions/56790926/exclude-files-staged-as-deleted-fom-git-ls-files - but I see not good cross-platform solution)
• ignore the failures with ENOENT code

Tohughts?