Add lint checking events

packages/next/build/index.ts

@@ -223,7 +223,8 @@ export default async function build(
             dir,
             lintDirs,
             config.experimental.cpus,
-            config.experimental.workerThreads
+            config.experimental.workerThreads,
+            telemetry
           )
         })
     }

packages/next/cli/next-lint.ts

@@ -8,6 +8,11 @@ import { cliCommand } from '../bin/next'
 import { ESLINT_DEFAULT_DIRS } from '../lib/constants'
 import { runLintCheck } from '../lib/eslint/runLintCheck'
 import { printAndExit } from '../server/lib/utils'
+import { Telemetry } from '../telemetry/storage'
+import loadConfig from '../next-server/server/config'
+import { PHASE_PRODUCTION_BUILD } from '../next-server/lib/constants'
+import { eventLintCheckCompleted } from '../telemetry/events'
+import { CompileError } from '../lib/compile-error'
 
 const eslintOptions = (args: arg.Spec) => ({
   overrideConfigFile: args['--config'] || null,
@@ -135,11 +140,35 @@ const nextLint: cliCommand = (argv) => {
     },
     []
   )
-
   runLintCheck(baseDir, lintDirs, false, eslintOptions(args))
-    .then((results) => {
-      if (results) {
-        console.log(results)
+    .then(async (lintResults) => {
+      const lintOutput =
+        typeof lintResults === 'string' ? lintResults : lintResults?.output
+
+      if (typeof lintResults !== 'string' && lintResults?.eventInfo) {
+        const conf = await loadConfig(PHASE_PRODUCTION_BUILD, baseDir)
+        const telemetry = new Telemetry({
+          distDir: join(baseDir, conf.distDir),
+        })
+        telemetry.record(
+          eventLintCheckCompleted({
+            ...lintResults.eventInfo,
+            buildLint: false,
+          })
+        )
+        await telemetry.flush()
+      }
+
+      if (
+        typeof lintResults !== 'string' &&
+        lintResults?.isError &&
+        lintOutput
+      ) {
+        throw new CompileError(lintOutput)
+      }
+
+      if (lintOutput) {
+        console.log(lintOutput)
       } else {
         console.log(chalk.green('✔ No ESLint warnings or errors'))
       }

packages/next/lib/eslint/customFormatter.ts

@@ -15,7 +15,7 @@ interface LintMessage {
   column: number
 }
 
-interface LintResult {
+export interface LintResult {
   filePath: string
   messages: LintMessage[]
   errorCount: number
@@ -28,7 +28,11 @@ function formatMessage(
   dir: string,
   messages: LintMessage[],
   filePath: string
-): string | void {
+): {
+  output: string
+  nextPluginErrorCount: number
+  nextPluginWarningCount: number
+} {
   let fileName = path.posix.normalize(
     path.relative(dir, filePath).replace(/\\/g, '/')
   )
@@ -38,6 +42,8 @@ function formatMessage(
   }
 
   let output = '\n' + chalk.cyan(fileName)
+  let nextPluginWarningCount = 0
+  let nextPluginErrorCount = 0
 
   for (let i = 0; i < messages.length; i++) {
     const { message, severity, line, column, ruleId } = messages[i]
@@ -53,6 +59,14 @@ function formatMessage(
         '  '
     }
 
+    if (ruleId?.includes('@next/next')) {
+      if (severity === MessageSeverity.Warning) {
+        nextPluginWarningCount += 1
+      } else {
+        nextPluginErrorCount += 1
+      }
+    }
+
     if (severity === MessageSeverity.Warning) {
       output += chalk.yellow.bold('Warning') + ': '
     } else {
@@ -66,19 +80,43 @@ function formatMessage(
     }
   }
 
-  return output
+  return {
+    output,
+    nextPluginErrorCount,
+    nextPluginWarningCount,
+  }
 }
 
-export function formatResults(baseDir: string, results: LintResult[]): string {
+export function formatResults(
+  baseDir: string,
+  results: LintResult[]
+): {
+  output: string
+  totalNextPluginErrorCount: number
+  totalNextPluginWarningCount: number
+} {
+  let totalNextPluginErrorCount = 0
+  let totalNextPluginWarningCount = 0
+
   const formattedResults = results
     .filter(({ messages }) => messages?.length)
-    .map(({ messages, filePath }) => formatMessage(baseDir, messages, filePath))
+    .map(({ messages, filePath }) => {
+      const res = formatMessage(baseDir, messages, filePath)
+      totalNextPluginErrorCount += res.nextPluginErrorCount
+      totalNextPluginWarningCount += res.nextPluginWarningCount
+      return res.output
+    })
     .join('\n')
 
-  return formattedResults.length > 0
-    ? formattedResults +
-        `\n\n${chalk.bold(
-          'Need to disable some ESLint rules? Learn more here:'
-        )} https://nextjs.org/docs/basic-features/eslint#disabling-rules\n`
-    : ''
+  return {
+    output:
+      formattedResults.length > 0
+        ? formattedResults +
+          `\n\n${chalk.bold(
+            'Need to disable some ESLint rules? Learn more here:'
+          )} https://nextjs.org/docs/basic-features/eslint#disabling-rules\n`
+        : '',
+    totalNextPluginErrorCount,
+    totalNextPluginWarningCount,
+  }
 }

packages/next/lib/eslint/runLintCheck.ts

@@ -9,13 +9,13 @@ import * as CommentJson from 'next/dist/compiled/comment-json'
 import { formatResults } from './customFormatter'
 import { writeDefaultConfig } from './writeDefaultConfig'
 import { existsSync, findPagesDir } from '../find-pages-dir'
-import { CompileError } from '../compile-error'
 import {
   hasNecessaryDependencies,
   NecessaryDependencies,
 } from '../has-necessary-dependencies'
 
 import * as Log from '../../build/output/log'
+import { EventLintCheckCompleted } from '../../telemetry/events/build'
 
 type Config = {
   plugins: string[]
@@ -29,14 +29,23 @@ async function lint(
   eslintrcFile: string | null,
   pkgJsonPath: string | null,
   eslintOptions: any = null
-): Promise<string | null> {
+): Promise<
+  | string
+  | null
+  | {
+      output: string | null
+      isError: boolean
+      eventInfo: EventLintCheckCompleted
+    }
+> {
   // Load ESLint after we're sure it exists:
-  const mod = await import(deps.resolved)
+  const mod = await import(deps.resolved.get('eslint')!)
 
   const { ESLint } = mod
+  let eslintVersion = ESLint.version
 
   if (!ESLint) {
-    const eslintVersion: string | undefined = mod?.CLIEngine?.version
+    eslintVersion = mod?.CLIEngine?.version
 
     if (!eslintVersion || semver.lt(eslintVersion, '7.0.0')) {
       return `${chalk.red(
@@ -99,22 +108,41 @@ async function lint(
       eslint = new ESLint(options)
     }
   }
+  const lintStart = process.hrtime()
+
   const results = await eslint.lintFiles(lintDirs)
   if (options.fix) await ESLint.outputFixes(results)
 
-  if (ESLint.getErrorResults(results)?.length > 0) {
-    throw new CompileError(await formatResults(baseDir, results))
+  const formattedResult = formatResults(baseDir, results)
+  const lintEnd = process.hrtime(lintStart)
+
+  return {
+    output: formattedResult.output,
+    isError: ESLint.getErrorResults(results)?.length > 0,
+    eventInfo: {
+      durationInSeconds: lintEnd[0],
+      eslintVersion: eslintVersion,
+      lintedFilesCount: results.length,
+      lintFix: !!options.fix,
+      nextEslintPluginVersion: nextEslintPluginIsEnabled
+        ? require(path.join(
+            path.dirname(deps.resolved.get('eslint-config-next')!),
+            'package.json'
+          )).version
+        : null,
+      nextEslintPluginErrorsCount: formattedResult.totalNextPluginErrorCount,
+      nextEslintPluginWarningsCount:
+        formattedResult.totalNextPluginWarningCount,
+    },
   }
-
-  return results?.length > 0 ? formatResults(baseDir, results) : null
 }
 
 export async function runLintCheck(
   baseDir: string,
   lintDirs: string[],
   lintDuringBuild: boolean = false,
   eslintOptions: any = null
-): Promise<string | null> {
+): ReturnType<typeof lint> {
   try {
     // Find user's .eslintrc file
     const eslintrcFile =

packages/next/lib/has-necessary-dependencies.ts

@@ -17,7 +17,7 @@ const requiredLintPackages = [
 ]
 
 export type NecessaryDependencies = {
-  resolved: string
+  resolved: Map<string, string>
 }
 
 export async function hasNecessaryDependencies(
@@ -46,9 +46,7 @@ export async function hasNecessaryDependencies(
 
   if (missingPackages.length < 1) {
     return {
-      resolved: checkESLintDeps
-        ? resolutions.get('eslint')!
-        : resolutions.get('typescript')!,
+      resolved: resolutions,
     }
   }
 

packages/next/lib/verifyAndLint.ts

@@ -3,12 +3,16 @@ import { Worker } from 'jest-worker'
 import { existsSync } from 'fs'
 import { join } from 'path'
 import { ESLINT_DEFAULT_DIRS } from './constants'
+import { Telemetry } from '../telemetry/storage'
+import { eventLintCheckCompleted } from '../telemetry/events'
+import { CompileError } from './compile-error'
 
 export async function verifyAndLint(
   dir: string,
   configLintDirs: string[] | undefined,
   numWorkers: number | undefined,
-  enableWorkerThreads: boolean | undefined
+  enableWorkerThreads: boolean | undefined,
+  telemetry: Telemetry
 ): Promise<void> {
   try {
     const lintWorkers = new Worker(require.resolve('./eslint/runLintCheck'), {
@@ -32,13 +36,30 @@ export async function verifyAndLint(
     )
 
     const lintResults = await lintWorkers.runLintCheck(dir, lintDirs, true)
-    if (lintResults) {
-      console.log(lintResults)
+    const lintOutput =
+      typeof lintResults === 'string' ? lintResults : lintResults?.output
+
+    if (typeof lintResults !== 'string' && lintResults?.eventInfo) {
+      telemetry.record(
+        eventLintCheckCompleted({
+          ...lintResults.eventInfo,
+          buildLint: true,
+        })
+      )
+    }
+
+    if (typeof lintResults !== 'string' && lintResults?.isError && lintOutput) {
+      await telemetry.flush()
+      throw new CompileError(lintOutput)
+    }
+
+    if (lintOutput) {
+      console.log(lintOutput)
     }
 
     lintWorkers.end()
   } catch (err) {
-    if (err.type === 'CompileError') {
+    if (err.type === 'CompileError' || err instanceof CompileError) {
       console.error(chalk.red('\nFailed to compile.'))
       console.error(err.message)
       process.exit(1)

packages/next/lib/verifyTypeScriptSetup.ts

@@ -38,7 +38,9 @@ export async function verifyTypeScriptSetup(
     )
 
     // Load TypeScript after we're sure it exists:
-    const ts = (await import(deps.resolved)) as typeof import('typescript')
+    const ts = (await import(
+      deps.resolved.get('typescript')!
+    )) as typeof import('typescript')
 
     if (semver.lt(ts.version, '4.3.2')) {
       log.warn(

packages/next/telemetry/events/build.ts

@@ -20,6 +20,27 @@ export function eventTypeCheckCompleted(
   }
 }
 
+const EVENT_LINT_CHECK_COMPLETED = 'NEXT_LINT_CHECK_COMPLETED'
+export type EventLintCheckCompleted = {
+  durationInSeconds: number
+  eslintVersion: string | null
+  lintedFilesCount?: number
+  lintFix?: boolean
+  buildLint?: boolean
+  nextEslintPluginVersion?: string | null
+  nextEslintPluginErrorsCount?: number
+  nextEslintPluginWarningsCount?: number
+}
+
+export function eventLintCheckCompleted(
+  event: EventLintCheckCompleted
+): { eventName: string; payload: EventLintCheckCompleted } {
+  return {
+    eventName: EVENT_LINT_CHECK_COMPLETED,
+    payload: event,
+  }
+}
+
 const EVENT_BUILD_COMPLETED = 'NEXT_BUILD_COMPLETED'
 type EventBuildCompleted = {
   durationInSeconds: number