fix(transformer): only run typescript plugin for typescript source

[Boshen]

closes #6865

TypeScript plugin changes import / export statements so it needs to be turned off for non-typescript files. This should also give a little performance boost for non-typescript files.

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[Boshen]

• fix(transformer): only run typescript plugin for typescript source #6889 👈
• main

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[codspeed-hq]

CodSpeed Performance Report

Merging #6889 will degrade performances by 3.2%

_{Comparing 10-25-fix_transformer_only_run_typescript_plugin_for_typescript_source (4dc5e51) with main (2d95009)}

Summary

⚡ 1 improvements
❌ 1 regressions
✅ 28 untouched benchmarks

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Benchmarks breakdown

	Benchmark	main	10-25-fix_transformer_only_run_typescript_plugin_for_typescript_source	Change
⚡	transformer[RadixUIAdoptionSection.jsx]	157.3 µs	152.2 µs	+3.34%
❌	transformer[checker.ts]	18.7 ms	19.3 ms	-3.2%

[overlookmotel]

⚡ transformer[RadixUIAdoptionSection.jsx] 157.6 µs 152.8 µs +3.1%
❌ transformer[checker.ts] 18.7 ms 19.3 ms -3.18%

I assume the regression for checker.ts is the cost of the extra "is TS enabled?" checks. We may be able to make those checks cheaper by using an is_ts_enabled boolean flag instead. But, as you said in #6865 (comment), we also want to avoid constructing the TS transformer if it's disabled - that setup cost will be significant for small JS files.

We should probably look at how transforms are constructed, and how options are stored, for all the transforms together once we've completed the rest of the ES6 transforms. We can probably gain some perf by refactoring it, one way or another.

But for now I say merge it! It speeds up all the benchmarks except checker.ts, and fixes loads of tests.

[Boshen]

Merge activity

• Oct 25, 9:59 AM EDT: The merge label '0-merge' was detected. This PR will be added to the Graphite merge queue once it meets the requirements.
• Oct 25, 9:59 AM EDT: A user added this pull request to the Graphite merge queue.
• Oct 25, 10:05 AM EDT: A user merged this pull request with the Graphite merge queue.