Performance degrades the more wildcards that are contained in TSConfig include or exclude patterns

🔎 Search Terms

wildcard pattern include exclude tsconfig regex regexp regular expression glob performance slow node

🕗 Version & Regression Information

• This is the behavior in every version I tried

⏯ Playground Link

No response

💻 Code

Create a TS project with any empty TS file and the following TSConfig.

{
  "compilerOptions": {
    "noCheck": true,
    "noEmit": true,
    "noResolve": true,
  },
  "exclude": [
    "alpha/beta/gamma/delta/epsilon/zeta/eta/theta/iota/kappa/lambda/**/*.ts",
    "alpha/beta/gamma/delta/epsilon/zeta/eta/theta/iota/kappa/lambda/**/*.ts",
    "alpha/beta/gamma/delta/epsilon/zeta/eta/theta/iota/kappa/lambda/**/*.ts",
    ...repeat a couple hundred or more times
  ]
}

I've created a repo to more easily reproduce the behavior: https://github.com/MichaelMitchell-at/typescript_slow_wildcards_repro

🙁 Actual behavior

tsc takes several seconds to run on the project, even though there is no work to do and there are no files to compare the exclude patterns against. In fact, running tsc with node --jitless is much faster than without.

🙂 Expected behavior

tsc should complete quickly.

Additional information about the issue

I've determined through profiling that the issue is that a giant RegExp combining all the patterns gets created which is very slow to evaluate.
https://github.com/microsoft/TypeScript/blob/739d729ecce60771c23723aad932ab35a34df82d/src/compiler/utilities.ts#L9556-L9566

From my testing, it's much faster to build a separate RegExp for each pattern and test them one by one for large number of patterns and for a small number of patterns there is no perceivable difference in speed. I've created a PR implementing this change which greatly improves the performance: https://github.com/microsoft/TypeScript/pull/61104

src/compiler/utilities.ts の9556-9566行目から始め、繰り返し指定した tsconfig exclude パターンを使って、リンク先の typescript_slow_wildcards_repro プロジェクトを実行します。大規模なパターンセットと小規模なパターンセットでコンパイラーの実行時間を比較し、期待されるパフォーマンス改善を検証する際には既存の PR 61104 を考慮します。