Various performance baselines for typescript-eslint.
## Usage
You'll need [hyperfine](https://github.com/sharkdp/hyperfine) installed locally, such as with `brew install hyperfine` or `winget install hyperfine`.
See [sharkdp/hyperfine#installation](https://github.com/sharkdp/hyperfine#installation).
```shell
npm install
npm run generate
npm run measure
```
You can manually measure individual cases by running `hyperfine ../../node_modules/eslint/bin/eslint.js --ignore-failure --warmup 1`.
### Measured Attributes
The `caseEntries` values in `src/data.ts` can be modified to test:
- `files`: roughly how many generated files should be linted
- `layout`: what rough shape of imports those files exhibit:
- `"even"`: a single root-level `index.ts` importing from roughly an even triangle shape of files
- `"references"`: a single root-level `tsconfig.json` with project references to a few projects
- `"wide"`: one root-level `index.ts` importing from all files in the project
- `singleRun`: whether to enable [single-run inference](https://v8--typescript-eslint.netlify.app/packages/parser#disallowautomaticsingleruninference) as a performance boost
- `types`: whether to use `parserOptions.project` or `parserOptions.projectService` for typed linting
## Results
Right now, `parserOptions.project` with single-run inference outperforms `parserOptions.projectService`.
This is a performance issue and we are investigating it as a bug.
```plaintext
┌───────┬───────────────────────┬───────────────────────┐
│ files │ project (even layout) │ service (even layout) │
├───────┼───────────────────────┼───────────────────────┤
│ 1024 │ '2.371 s ± 0.029 s' │ '2.724 s ± 0.049 s' │
└───────┴───────────────────────┴───────────────────────┘
```
See [typescript-eslint/typescript-eslint#9571 Performance: parserOptions.projectService no longer outperforms parserOptions.project](https://github.com/typescript-eslint/typescript-eslint/issues/9571) in typescript-eslint.
### Result Measurement Notes
- Example measurements taken on an M1 Max Mac Studio with Node.js 22.12.0
- These results are similar across TypeScript versions: 5.0.4, 5.4.5, and 5.5.3
## Comparisons
The [`comparisons/`](./comparisons) directory contains details on more specific comparisons.
See each `comparisons/*.md` file for details on what's being measured.
## Traces
The [`traces/`](./traces) directory contains more specific traces for investigations.
> ✨ You might consider using [0x](https://github.com/davidmarkclements/0x) for nice flamegraph visuals.
All comparisons were run on a common shape of linting: 1024 files with the "even" (triangle-shaped) imports layout.
## Contributors
