# ts-checker-rspack-plugin
Rspack plugin that runs TypeScript type checker on a separate process.
## Credits
This plugin is forked from [TypeStrong/fork-ts-checker-webpack-plugin](https://github.com/TypeStrong/fork-ts-checker-webpack-plugin), which is created by [Piotr OleΕ](https://github.com/piotr-oles). See the original project's [LICENSE](https://github.com/TypeStrong/fork-ts-checker-webpack-plugin/blob/main/LICENSE).
Big thanks to `fork-ts-checker-webpack-plugin` creators and contributors for their great work. β€οΈ
## Features
- Speeds up [TypeScript](https://github.com/Microsoft/TypeScript) type checking (by moving it to a separate process) π
- Supports modern TypeScript features like [project references](https://www.typescriptlang.org/docs/handbook/project-references.html) and [incremental mode](https://www.typescriptlang.org/docs/handbook/release-notes/typescript-3-4.html#faster-subsequent-builds-with-the---incremental-flag) β¨
- Displays nice error messages with the [code frame](https://babeljs.io/docs/en/next/babel-code-frame.html) formatter π
π‘ For Rsbuild projects, use [@rsbuild/plugin-type-check](https://github.com/rspack-contrib/rsbuild-plugin-type-check) to get out-of-the-box experience.
## Installation
This plugin requires **Node.js >=16.0.0+**, **Rspack ^1.0.0**, **TypeScript ^3.8.0**
```sh
# with npm
npm install -D ts-checker-rspack-plugin
# with yarn
yarn add -D ts-checker-rspack-plugin
# with pnpm
pnpm add -D ts-checker-rspack-plugin
```
The minimal Rspack config with [builtin:swc-loader](https://rspack.dev/guide/features/builtin-swc-loader).
```js
// rspack.config.mjs
import { TsCheckerRspackPlugin } from 'ts-checker-rspack-plugin';
export default {
entry: './src/index.ts',
resolve: {
extensions: ['.ts', '.tsx', '.js'],
},
module: {
rules: [
{
test: /\.tsx?$/,
loader: 'builtin:swc-loader',
options: {
jsc: {
parser: {
syntax: 'typescript',
},
},
},
},
],
},
plugins: [new TsCheckerRspackPlugin()],
};
```
If you are using CommonJS:
```js
// rspack.config.js
const { TsCheckerRspackPlugin } = require('ts-checker-rspack-plugin');
module.exports = {
plugins: [new TsCheckerRspackPlugin()],
};
```
## Modules resolution
It's very important to be aware that **this plugin uses [TypeScript](https://github.com/Microsoft/TypeScript)'s, not
Rspack's modules resolution**. It means that you have to setup `tsconfig.json` correctly.
> It's because of the performance - with TypeScript's module resolution we don't have to wait for Rspack to compile files.
>
> To debug TypeScript's modules resolution, you can use `tsc --traceResolution` command.
## Options
| Name | Type | Default value | Description |
| ------------ | ---------------------------------------------------------------- | ----------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `async` | `boolean` | `compiler.options.mode === 'development'` | If `true`, reports issues **after** Rspack's compilation is done. Thanks to that it doesn't block the compilation. Used only in the `watch` mode. |
| `typescript` | `object` | `{}` | See [TypeScript options](#typescript-options). |
| `issue` | `object` | `{}` | See [Issues options](#issues-options). |
| `formatter` | `string` or `object` or `function` | `codeframe` | Available formatters are `basic`, `codeframe` and a custom `function`. To [configure](https://babeljs.io/docs/en/babel-code-frame#options) `codeframe` formatter, pass: `{ type: 'codeframe', options: { } }`. To use absolute file path, pass: `{ type: 'codeframe', pathType: 'absolute' }`. |
| `logger` | `{ log: function, error: function }` or `webpack-infrastructure` | `console` | Console-like object to print issues in `async` mode. |
| `devServer` | `boolean` | `true` | If set to `false`, errors will not be reported to Dev Server and displayed in the error overlay. |
### TypeScript options
Options for the TypeScript checker (`typescript` option object).
| Name | Type | Default value | Description |
| ------------------- | ------------------------------------------------------------------------------ | -------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| `memoryLimit` | `number` | `8192` | Memory limit for the checker process in MB. If the process exits with the allocation failed error, try to increase this number. |
| `configFile` | `string` | `'tsconfig.json'` | Path to the `tsconfig.json` file (path relative to the `compiler.options.context` or absolute path) |
| `configOverwrite` | `object` | `{ compilerOptions: { skipLibCheck: true, sourceMap: false, inlineSourceMap: false, declarationMap: false } }` | This configuration will overwrite configuration from the `tsconfig.json` file. Supported fields are: `extends`, `compilerOptions`, `include`, `exclude`, `files`, and `references`. |
| `context` | `string` | `dirname(configuration.configFile)` | The base path for finding files specified in the `tsconfig.json`. Same as the `context` option from the [ts-loader](https://github.com/TypeStrong/ts-loader#context). Useful if you want to keep your `tsconfig.json` in an external package. Keep in mind that **not** having a `tsconfig.json` in your project root can cause different behaviour between `ts-checker-rspack-plugin` and `tsc`. When using editors like `VS Code` it is advised to add a `tsconfig.json` file to the root of the project and extend the config file referenced in option `configFile`. |
| `build` | `boolean` | `false` | The equivalent of the `--build` flag for the `tsc` command. |
| `mode` | `'readonly'` or `'write-dts'` or `'write-tsbuildinfo'` or `'write-references'` | `build === true ? 'write-tsbuildinfo' ? 'readonly'` | Use `readonly` if you don't want to write anything on the disk, `write-dts` to write only `.d.ts` files, `write-tsbuildinfo` to write only `.tsbuildinfo` files, `write-references` to write both `.js` and `.d.ts` files of project references (last 2 modes requires `build: true`). |
| `diagnosticOptions` | `object` | `{ syntactic: false, semantic: true, declaration: false, global: false }` | Settings to select which diagnostics do we want to perform. |
| `profile` | `boolean` | `false` | Measures and prints timings related to the TypeScript performance. |
| `typescriptPath` | `string` | `require.resolve('typescript')` | If supplied this is a custom path where TypeScript can be found. |
### Issues options
Options for the issues filtering (`issue` option object).
I could write some plain text explanation of these options but I think code will explain it better:
```typescript
interface Issue {
severity: 'error' | 'warning';
code: string;
file?: string;
}
type IssueMatch = Partial; // file field supports glob matching
type IssuePredicate = (issue: Issue) => boolean;
type IssueFilter = IssueMatch | IssuePredicate | (IssueMatch | IssuePredicate)[];
```
| Name | Type | Default value | Description |
| --------- | ------------- | ------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `include` | `IssueFilter` | `undefined` | If `object`, defines issue properties that should be [matched](src/issue/issue-match.ts). If `function`, acts as a predicate where `issue` is an argument. |
| `exclude` | `IssueFilter` | `undefined` | Same as `include` but issues that match this predicate will be excluded. |
Expand example
Include issues from the `src` directory, exclude issues from `.spec.ts` files:
```js
module.exports = {
// ...the Rspack configuration
plugins: [
new TsCheckerRspackPlugin({
issue: {
include: [{ file: '**/src/**/*' }],
exclude: [{ file: '**/*.spec.ts' }],
},
}),
],
};
```
## Plugin hooks
This plugin provides some custom Rspack hooks:
| Hook key | Type | Params | Description |
| ---------- | -------------------------- | --------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| `start` | `AsyncSeriesWaterfallHook` | `change, compilation` | Starts issues checking for a compilation. It's an async waterfall hook, so you can modify the list of changed and removed files or delay the start of the service. |
| `waiting` | `SyncHook` | `compilation` | Waiting for the issues checking. |
| `canceled` | `SyncHook` | `compilation` | Issues checking for the compilation has been canceled. |
| `error` | `SyncHook` | `compilation` | An error occurred during issues checking. |
| `issues` | `SyncWaterfallHook` | `issues, compilation` | Issues have been received and will be reported. It's a waterfall hook, so you can modify the list of received issues. |
To access plugin hooks and tap into the event, we need to use the `getCompilerHooks` static method.
When we call this method with a [Rspack compiler instance](https://rspack.dev/api/javascript-api/compiler), it returns the object with
[tapable](https://github.com/webpack/tapable) hooks where you can pass in your callbacks.
```js
// ./src/rspack/MyRspackPlugin.js
const { TsCheckerRspackPlugin } = require('ts-checker-rspack-plugin');
class MyRspackPlugin {
apply(compiler) {
const hooks = TsCheckerRspackPlugin.getCompilerHooks(compiler);
// log some message on waiting
hooks.waiting.tap('MyPlugin', () => {
console.log('waiting for issues');
});
// don't show warnings
hooks.issues.tap('MyPlugin', (issues) => issues.filter((issue) => issue.severity === 'error'));
}
}
module.exports = MyRspackPlugin;
// rspack.config.js
const { TsCheckerRspackPlugin } = require('ts-checker-rspack-plugin');
const MyRspackPlugin = require('./src/rspack/MyRspackPlugin');
module.exports = {
/* ... */
plugins: [new TsCheckerRspackPlugin(), new MyRspackPlugin()],
};
```
## Profiling types resolution
When using TypeScript 4.3.0 or newer you can profile long type checks by
setting "generateTrace" compiler option. This is an instruction from [microsoft/TypeScript#40063](https://github.com/microsoft/TypeScript/pull/40063):
1. Set "generateTrace": "{folderName}" in your `tsconfig.json` (under `compilerOptions`)
2. Look in the resulting folder. If you used build mode, there will be a `legend.json` telling you what went where.
Otherwise, there will be `trace.json` file and `types.json` files.
3. Navigate to [edge://tracing](edge://tracing) or [chrome://tracing](chrome://tracing) and load `trace.json`
4. Expand Process 1 with the little triangle in the left sidebar
5. Click on different blocks to see their payloads in the bottom pane
6. Open `types.json` in an editor
7. When you see a type ID in the tracing output, go-to-line {id} to find data about that type
## Enabling incremental mode
You must both set "incremental": true in your `tsconfig.json` (under `compilerOptions`) and also specify mode: 'write-references' in `TsCheckerRspackPlugin` settings.
## License
MIT License