Provide full src path to transform

[floryst]

Instead of passing in just the basename of the source file, pass in the full src path.
This is useful when needing to rewrite contents that contain relative references to other files.

[aperron]

I need this too.

To avoid regressions, maybe
...(transform && { contents: await transform(await fs.readFile(src), base, src) }),
OR
...(transform && { contents: await transform(await fs.readFile(src), base, dir) }),

[codecov-commenter]

⚠️ Please install the to ensure uploads and comments are reliably processed by Codecov.

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (507bf5e) to head (c8b92ee).
⚠️ Report is 4 commits behind head on master.
❗ Your organization needs to install the Codecov GitHub app to enable full functionality.

Additional details and impacted files

@@            Coverage Diff            @@
##            master       #58   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files            1         1           
  Lines           50        50           
  Branches        17        17           
=========================================
  Hits            50        50           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.