Proposed changes

Change 4292733 introduced a regression where TypeScript files get loaded using both -r ts-node/register AND --loader ts-node/esm/transpile-only, preventing source maps from working correctly:

Even though one part of ts-node documentation seems to indicate that specifying both flags should be supported, another part talks about specifying only one of the flags at the time.

Looking at the source code of ts-node/esm/transpile-only, we can see that the method registerAndCreateEsmHooks already calls register(opts), which means specifying the flag -r ts-node/register is redundant.

From what I've observed, using both flags results in TS Node incorrectly mapping the resulting JavaScript to the original TypeScript, which means that stack traces point to incorrect lines.

I've modified @wdio/cli running locally on a CJS project to remove the ts-node/register flag and the stack traces started to work correctly again.

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update

Checklist

• I have read the CONTRIBUTING doc
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)
• I have added proper type definitions for new commands (if appropriate)

Further comments

Reviewers: @webdriverio/project-committers