fix: lint newly created files in dev watchers

packages/vite-plugin-checker/__tests__/newLintFile.spec.ts

@@ -0,0 +1,118 @@
+import { mkdir, mkdtemp, rm, writeFile } from 'node:fs/promises'
+import path from 'node:path'
+import { Worker } from 'node:worker_threads'
+import { expect, it } from 'vitest'
+import { ACTION_TYPES } from '../src/types'
+
+const cases = [
+  {
+    name: 'eslint',
+    configFile: 'eslint.config.mjs',
+    config:
+      'export default [{files: ["**/*.js"], rules: {"no-var": "error"}}]\n',
+    checker: { eslint: { lintCommand: 'eslint src', dev: { debounceMs: 10 } } },
+    extension: 'js',
+    initial: 'const initial = 1;\n',
+    added: 'var added = 1;\n',
+    message: 'Unexpected var',
+  },
+  {
+    name: 'stylelint',
+    configFile: '.stylelintrc.json',
+    config: JSON.stringify({ rules: { 'color-no-invalid-hex': true } }),
+    checker: {
+      stylelint: {
+        lintCommand: 'stylelint "src/*.css"',
+        dev: { debounceMs: 10 },
+      },
+    },
+    extension: 'css',
+    initial: 'a { color: #fff; }\n',
+    added: 'a { color: #xyz; }\n',
+    message: 'Invalid hex color',
+  },
+  {
+    name: 'biome',
+    configFile: 'biome.json',
+    config: JSON.stringify({
+      formatter: { enabled: false },
+      linter: {
+        rules: { recommended: false, suspicious: { noDebugger: 'error' } },
+      },
+    }),
+    checker: { biome: { command: 'lint', dev: { debounceMs: 10 } } },
+    extension: 'js',
+    initial: 'const initial = 1;\n',
+    added: 'debugger;\n',
+    message: 'debugger',
+  },
+]
+
+it.each(
+  cases,
+)('reports $name diagnostics for a newly added file without a second save', async (entry) => {
+  const root = await mkdtemp(path.join(import.meta.dirname, 'lint-add-'))
+  const messages: unknown[] = []
+  let worker: Worker | undefined
+  let workerError: Error | undefined
+  try {
+    await mkdir(path.join(root, 'src'))
+    await writeFile(
+      path.join(root, `src/initial.${entry.extension}`),
+      entry.initial,
+    )
+    await writeFile(path.join(root, entry.configFile), entry.config)
+    worker = new Worker(
+      new URL(`../dist/checkers/${entry.name}/main.js`, import.meta.url),
+      {
+        workerData: {
+          env: { command: 'serve', mode: 'development' },
+          checkerConfig: entry.checker,
+        },
+      },
+    )
+    worker.on('message', (message) => messages.push(message))
+    worker.on('error', (error) => {
+      workerError = error
+    })
+    worker.postMessage({
+      type: ACTION_TYPES.config,
+      payload: { enableOverlay: true, enableTerminal: false },
+    })
+    worker.postMessage({
+      type: ACTION_TYPES.configureServer,
+      payload: { root },
+    })
+    await expect
+      .poll(() => messages.length, { timeout: 10000 })
+      .toBeGreaterThan(0)
+    // Prove the watcher is ready via an existing file before creating a new one.
+    await expect
+      .poll(
+        async () => {
+          await writeFile(
+            path.join(root, `src/initial.${entry.extension}`),
+            entry.added,
+          )
+          return JSON.stringify(messages)
+        },
+        { timeout: 5000 },
+      )
+      .toContain(entry.message)
+    messages.length = 0
+    await writeFile(
+      path.join(root, `src/added.${entry.extension}`),
+      entry.added,
+    )
+    await expect
+      .poll(() => JSON.stringify(messages).replace(/\\\\/g, '/'), {
+        timeout: 5000,
+      })
+      .toContain(`src/added.${entry.extension}`)
+    expect(JSON.stringify(messages)).toContain(entry.message)
+    expect(workerError).toBeUndefined()
+  } finally {
+    await worker?.terminate()
+    await rm(root, { recursive: true, force: true })
+  }
+}, 20000)

packages/vite-plugin-checker/src/checkers/biome/main.ts

@@ -140,11 +140,14 @@ const createDiagnostic: CreateDiagnostic<'biome'> = (pluginConfig) => {
 
       const watcher = chokidar.watch(watchTarget, {
         cwd: root,
+        ignoreInitial: true,
         ignored: (p: string) => p.includes('node_modules'),
       })
-      watcher.on('change', (filePath) => {
+      const scheduleLintFile = (filePath: string) => {
         scheduler.schedule(path.resolve(root, filePath))
-      })
+      }
+      watcher.on('add', scheduleLintFile)
+      watcher.on('change', scheduleLintFile)
       watcher.on('unlink', (filePath) => {
         const absPath = path.resolve(root, filePath)
         manager.updateByFileId(absPath, [])

packages/vite-plugin-checker/src/checkers/eslint/main.ts

@@ -229,17 +229,20 @@ const createDiagnostic: CreateDiagnostic<'eslint'> = (pluginConfig) => {
 
       const watcher = chokidar.watch(watchTarget, {
         cwd: root,
+        ignoreInitial: true,
         ignored: createIgnore(root, files),
       })
 
-      watcher.on('change', (filePath) => {
+      const scheduleLintFile = (filePath: string) => {
         const absPath = path.resolve(root, filePath)
         shouldLintPath(absPath)
           .then((shouldLint) => {
             if (shouldLint) scheduler.schedule(absPath)
           })
           .catch(ignoreTransientFsError)
-      })
+      }
+      watcher.on('add', scheduleLintFile)
+      watcher.on('change', scheduleLintFile)
       watcher.on('unlink', (filePath) => {
         const absPath = path.resolve(root, filePath)
         manager.updateByFileId(absPath, [])

packages/vite-plugin-checker/src/checkers/stylelint/main.ts

@@ -138,12 +138,15 @@ const createDiagnostic: CreateDiagnostic<'stylelint'> = (pluginConfig) => {
 
       const watcher = chokidar.watch(watchTarget, {
         cwd: root,
+        ignoreInitial: true,
         ignored: createIgnore(root, translatedOptions.files),
       })
 
-      watcher.on('change', (filePath) => {
+      const scheduleLintFile = (filePath: string) => {
         scheduler.schedule(path.resolve(root, filePath))
-      })
+      }
+      watcher.on('add', scheduleLintFile)
+      watcher.on('change', scheduleLintFile)
       watcher.on('unlink', (filePath) => {
         const absPath = path.resolve(root, filePath)
         manager.updateByFileId(absPath, [])