Use compiled JS output for line number selection with TypeScript

[danielalanbates]

Summary

Fixes #3064

When @ava/typescript is configured, line number selection (e.g. ava test.ts:10) fails because acorn cannot parse TypeScript syntax. This PR resolves the compiled JavaScript output file using the provider state's rewritePaths and parses that instead.

Changes

• lib/worker/base.js: Added resolveCompiledFile() which uses the TypeScript provider state (extensions and rewritePaths) to map a .ts/.cts/.mts source file to its compiled .js/.cjs/.mjs output. The resolved path is passed to lineNumberSelection().

• lib/worker/line-numbers.js: Accepts an optional compiledFile parameter. When provided:

  • Parses the compiled JavaScript instead of the TypeScript source
  • Looks up the source map for the compiled file (so positions translate back to the original TS source)
  • Matches callsites against both the original source file and the compiled file (extracted the comparison into a matchesFile() helper to avoid duplication)

How it works

1. resolveCompiledFile() replicates the path rewriting logic from @ava/typescript's worker.load() — using the same rewritePaths and extension mapping that are already available in providerStates
2. The compiled JS is parsed by acorn (which it can handle)
3. Source map translation (already present) maps compiled JS positions back to TypeScript line numbers
4. The user's selected line numbers (from the TS source) match correctly

Compatibility

• No changes required to @ava/typescript — uses existing provider state data
• When no TypeScript provider is configured, compiledFile is null and behavior is unchanged
• All existing line number tests continue to pass (1615/1615 tap tests pass)

This PR was created with the assistance of Claude Opus 4.6 by Anthropic. Happy to make any adjustments! Reviewed and submitted by a human.

[sindresorhus]

A few things I think needs to be improved:

• Move path resolution out of core and into provider capability. Core should not reimplement provider-specific rewritePaths logic.
• Only resolve compiled targets when line-number selection is actually requested, not on every worker startup.
• Add regression coverage for TypeScript line selection end to end (test.ts:line), including rewrite-path setups.
• Add at least one edge-case test for overlapping rewrite rules so the most specific mapping is used.
• Keep the current fallback behavior for older provider versions so compatibility is preserved.

[danielalanbates]

Thank you for your time reviewing this. We're withdrawing this PR. Apologies for any inconvenience.