fix(playwright): shell- and regex-escape test paths

[pbomb]

Problem

packages/playwright's onSuccess joins test file paths with spaces and passes them to npx playwright test via shell: true. Two related bugs make this break on real-world repos:

1. Shell metacharacters break /bin/sh parsing

Paths are not shell-escaped, so any shell metacharacter in a path breaks the parser before Playwright ever runs. The batch never produces .knapsack-pro/batch.json, and the next readFileSync('.knapsack-pro/batch.json') throws ENOENT, failing the whole CI job.

We hit this at Gusto. Our Playwright tests live under route-group folders like apps/gusto/libs/app-*/src/pages/(layout)/. The ( breaks /bin/sh parsing on the Knapsack-spawned command:

/bin/sh: 1: Syntax error: "(" unexpected
Error: ENOENT: no such file or directory, open '.knapsack-pro/batch.json'

2. Playwright treats positional args as regex filters

Even with shell-escaping, Playwright's CLI interprets each positional argument as a regex matched against test file paths, not a literal path. Paths containing regex metacharacters (., (, ), [, ], *, +, ?, ^, $, {, }, |, \) fail to match the intended file, and Playwright errors with:

Error: No tests found

I confirmed this layer was necessary by running CI with only the shell-escape fix: batches whose paths had no regex metacharacters ran cleanly, but every batch that included a (...)-named folder hit "No tests found".

Fix

Two-layer escape on each path before joining:

1. Regex-escape so Playwright's positional-arg regex matches the literal path.
2. Single-quote (with the standard '\'' inner-quote escape) so the shell passes the regex-escaped string through unchanged.

Organized as two commits:

• fix(playwright): shell-escape test paths in onSuccess
• fix(playwright): regex-escape test paths for Playwright CLI

Compatibility

No public API change. Paths with no shell or regex metacharacters behave identically.

[3v0k4]

Hey Matt, thanks for the PR and the detailed description.

We'll review as soon as possible.

I see this is a draft, are you planning to do more work on this? Does this fix all the issues you have with PW?

[pbomb]

Hi @3v0k4. I just marked it ready to review after bringing another change that actually fixed the issue for us. It wasn't quite right after the first commit. Happy to work with you on and test out any different approaches you might have.