feat: introduce watchTriggerPatterns option

docs/config/index.md

@@ -697,6 +697,36 @@ In interactive environments, this is the default, unless `--run` is specified ex
 
 In CI, or when run from a non-interactive shell, "watch" mode is not the default, but can be enabled explicitly with this flag.
 
+### watchTriggerPatterns <Version>3.2.0</Version><NonProjectOption /> {#watchtriggerpatterns}
+
+- **Type:** `WatcherTriggerPattern[]`
+
+Vitest reruns tests based on the module graph which is populated by static and dynamic `import` statements. However, if you are reading from the file system or fetching from a proxy, then Vitest cannot detect those dependencies.
+
+To correctly rerun those tests, you can define a regex pattern and a function that retuns a list of test files to run.
+
+```ts
+import { defineConfig } from 'vitest/config'
+
+export default defineConfig({
+  test: {
+    watchTriggerPatterns: [
+      {
+        pattern: /^src\/(mailers|templates)\/(.*)\.(ts|html|txt)$/,
+        testToRun: (match) => {
+          // relative to the root value
+          return `./api/tests/mailers/${match[2]}.test.ts`
+        },
+      },
+    ],
+  },
+})
+```
+
+::: warning
+Returned files should be either absolute or relative to the root. Note that this is a global option, and it cannot be used inside of [project](/guide/workspace) configs.
+:::
+
 ### root
 
 - **Type:** `string`

packages/vitest/src/node/cli/cli-config.ts

@@ -863,6 +863,7 @@ export const cliOptionsConfig: VitestCLIOptions = {
   json: null,
   provide: null,
   filesOnly: null,
+  watchTriggerPatterns: null,
 }
 
 export const benchCliOptionsConfig: Pick<

packages/vitest/src/node/types/config.ts

@@ -16,6 +16,7 @@ import type {
   BuiltinReporters,
 } from '../reporters'
 import type { TestSequencerConstructor } from '../sequencers/types'
+import type { WatcherTriggerPattern } from '../watcher'
 import type { BenchmarkUserOptions } from './benchmark'
 import type { BrowserConfigOptions, ResolvedBrowserOptions } from './browser'
 import type { CoverageOptions, ResolvedCoverageOptions } from './coverage'
@@ -491,6 +492,12 @@ export interface InlineConfig {
    */
   forceRerunTriggers?: string[]
 
+  /**
+   * Pattern configuration to rerun only the tests that are affected
+   * by the changes of specific files in the repository.
+   */
+  watchTriggerPatterns?: WatcherTriggerPattern[]
+
   /**
    * Coverage options
    */
@@ -1094,6 +1101,7 @@ type NonProjectOptions =
   | 'minWorkers'
   | 'fileParallelism'
   | 'workspace'
+  | 'watchTriggerPatterns'
 
 export type ProjectConfig = Omit<
   InlineConfig,

packages/vitest/src/node/watcher.ts

@@ -3,6 +3,7 @@ import type { TestProject } from './project'
 import { readFileSync } from 'node:fs'
 import { noop, slash } from '@vitest/utils'
 import mm from 'micromatch'
+import { resolve } from 'pathe'
 
 export class VitestWatcher {
   /**
@@ -54,14 +55,42 @@ export class VitestWatcher {
     this._onRerun.forEach(cb => cb(file))
   }
 
+  private getTestFilesFromWatcherTrigger(id: string): boolean {
+    if (!this.vitest.config.watchTriggerPatterns) {
+      return false
+    }
+    let triggered = false
+    this.vitest.config.watchTriggerPatterns.forEach((definition) => {
+      const exec = definition.pattern.exec(id)
+      if (exec) {
+        const files = definition.testsToRun(id, exec)
+        if (Array.isArray(files)) {
+          triggered = true
+          files.forEach(file => this.changedTests.add(resolve(this.vitest.config.root, file)))
+        }
+        else if (typeof files === 'string') {
+          triggered = true
+          this.changedTests.add(resolve(this.vitest.config.root, files))
+        }
+      }
+    })
+    return triggered
+  }
+
   private onChange = (id: string): void => {
     id = slash(id)
     this.vitest.logger.clearHighlightCache(id)
     this.vitest.invalidateFile(id)
-    const needsRerun = this.handleFileChanged(id)
-    if (needsRerun) {
+    const testFiles = this.getTestFilesFromWatcherTrigger(id)
+    if (testFiles) {
       this.scheduleRerun(id)
     }
+    else {
+      const needsRerun = this.handleFileChanged(id)
+      if (needsRerun) {
+        this.scheduleRerun(id)
+      }
+    }
   }
 
   private onUnlink = (id: string): void => {
@@ -82,6 +111,13 @@ export class VitestWatcher {
   private onAdd = (id: string): void => {
     id = slash(id)
     this.vitest.invalidateFile(id)
+
+    const testFiles = this.getTestFilesFromWatcherTrigger(id)
+    if (testFiles) {
+      this.scheduleRerun(id)
+      return
+    }
+
     let fileContent: string | undefined
 
     const matchingProjects: TestProject[] = []
@@ -171,3 +207,11 @@ export class VitestWatcher {
     return !!files.length
   }
 }
+
+export interface WatcherTriggerPattern {
+  pattern: RegExp
+  testsToRun: (
+    file: string,
+    match: RegExpMatchArray
+  ) => string[] | string | null | undefined | void
+}

packages/vitest/src/public/config.ts

@@ -19,6 +19,7 @@ export {
   defaultExclude,
   defaultInclude,
 } from '../defaults'
+export type { WatcherTriggerPattern } from '../node/watcher'
 export { mergeConfig } from 'vite'
 export type { Plugin } from 'vite'
 

packages/vitest/src/public/node.ts

@@ -130,13 +130,15 @@ export type { TestRunResult } from '../node/types/tests'
 export const TestFile: typeof _TestFile = _TestFile
 export type { WorkerContext } from '../node/types/worker'
 export { createViteLogger } from '../node/viteLogger'
-export { distDir, rootDir } from '../paths'
+export type { WatcherTriggerPattern } from '../node/watcher'
 
 /**
  * @deprecated Use `ModuleDiagnostic` instead
  */
 export type FileDiagnostic = _FileDiagnostic
 
+export { distDir, rootDir } from '../paths'
+
 export type {
   CollectLineNumbers as TypeCheckCollectLineNumbers,
   CollectLines as TypeCheckCollectLines,
@@ -147,9 +149,7 @@ export type {
 } from '../typecheck/types'
 
 export type { TestExecutionMethod as TestExecutionType } from '../types/worker'
-
 export { createDebugger } from '../utils/debugger'
-
 export type {
   RunnerTask,
   RunnerTaskResult,

test/config/fixtures/watch-trigger-pattern/folder/fs/basic.test.ts

@@ -0,0 +1,9 @@
+import { readFileSync } from 'node:fs';
+import { resolve } from 'node:path';
+import { expect, test } from 'vitest';
+
+const filepath = resolve(import.meta.dirname, './text.txt');
+
+test('basic', () => {
+  expect(readFileSync(filepath, 'utf-8')).toBe('hello world\n');
+})

test/config/fixtures/watch-trigger-pattern/folder/fs/text.txt

@@ -0,0 +1 @@
+hello world

test/config/fixtures/watch-trigger-pattern/vitest.config.ts

@@ -0,0 +1,14 @@
+import { defineConfig } from 'vitest/config';
+
+export default defineConfig({
+  test: {
+    watchTriggerPatterns: [
+      {
+        pattern: /folder\/(\w+)\/.*\.txt$/,
+        testsToRun: (id, match) => {
+          return `./folder/${match[1]}/basic.test.ts`;
+        },
+      }
+    ]
+  }
+})

test/config/test/watch-trigger-pattern.test.ts

@@ -0,0 +1,25 @@
+import { resolve } from 'node:path'
+import { expect, test } from 'vitest'
+import { editFile, runVitest } from '../../test-utils'
+
+const root = resolve(import.meta.dirname, '../fixtures/watch-trigger-pattern')
+
+test('watch trigger pattern picks up the file', async () => {
+  const { stderr, vitest } = await runVitest({
+    root,
+    watch: true,
+  })
+
+  expect(stderr).toBe('')
+
+  await vitest.waitForStdout('Waiting for file changes')
+
+  editFile(
+    resolve(root, 'folder/fs/text.txt'),
+    content => content.replace('world', 'vitest'),
+  )
+
+  await vitest.waitForStderr('basic.test.ts')
+
+  expect(vitest.stderr).toContain(`expected 'hello vitest\\n' to be 'hello world\\n'`)
+})