feat: Make Vitest runs more token efficient when run through a coding assistant.

cpojer · cpojer · commit ea67b09f0bf5 · 2026-03-04T15:11:40.000+09:00
diff --git a/packages/vitest/src/node/cli/cac.ts b/packages/vitest/src/node/cli/cac.ts
@@ -300,6 +300,10 @@ function normalizeCliOptions(cliFilters: string[], argv: CliOptions): CliOptions
 
 async function start(mode: VitestRunMode, cliFilters: string[], options: CliOptions): Promise<void> {
   try {
+    const { detectAgent } = await import('../../utils/env')
+    if (detectAgent()) {
+      options.env = { AI_AGENT: '1', ...options.env }
+    }
     const { startVitest } = await import('./cli-api')
     const ctx = await startVitest(mode, cliFilters.map(normalize), normalizeCliOptions(cliFilters, options))
     if (!ctx.shouldKeepServer()) {
diff --git a/packages/vitest/src/node/reporters/base.ts b/packages/vitest/src/node/reporters/base.ts
@@ -37,6 +37,7 @@ const BADGE_PADDING = '       '
 
 export interface BaseOptions {
   isTTY?: boolean
+  isAgent?: boolean
 }
 
 export abstract class BaseReporter implements Reporter {
@@ -49,12 +50,14 @@ export abstract class BaseReporter implements Reporter {
   renderSucceed = false
 
   protected verbose = false
+  protected isAgent = false
 
   private _filesInWatchMode = new Map<string, number>()
   private _timeStart = formatTimeString(new Date())
 
   constructor(options: BaseOptions = {}) {
     this.isTTY = options.isTTY ?? isTTY
+    this.isAgent = options.isAgent ?? false
   }
 
   onInit(ctx: Vitest): void {
@@ -118,7 +121,7 @@ export abstract class BaseReporter implements Reporter {
   }
 
   private logFailedTask(task: Task) {
-    if (this.ctx.config.silent === 'passed-only') {
+    if (this.ctx.config.silent === 'passed-only' || this.isAgent) {
       for (const log of task.logs || []) {
         this.onUserConsoleLog(log, 'failed')
       }
@@ -131,6 +134,10 @@ export abstract class BaseReporter implements Reporter {
       return
     }
 
+    if (this.isAgent && moduleState !== 'failed') {
+      return
+    }
+
     let testsCount = 0
     let failedCount = 0
     let skippedCount = 0
@@ -200,6 +207,10 @@ export abstract class BaseReporter implements Reporter {
       this.log(c.red(` ${padding}${taskFail} ${this.getTestName(test.task, separator)}`) + suffix)
     }
 
+    else if (this.isAgent) {
+      // In agent mode, only print failed tests
+    }
+
     // also print slow tests
     else if (duration > this.ctx.config.slowTestThreshold) {
       this.log(` ${padding}${c.yellow(c.dim(F_CHECK))} ${this.getTestName(test.task, separator)} ${suffix}`)
@@ -500,6 +511,10 @@ export abstract class BaseReporter implements Reporter {
       return false
     }
 
+    if (this.isAgent && taskState !== 'failed') {
+      return false
+    }
+
     if (this.ctx.config.onConsoleLog) {
       const task = log.taskId ? this.ctx.state.idMap.get(log.taskId) : undefined
       const entity = task && this.ctx.state.getReportedEntity(task)
diff --git a/packages/vitest/src/node/reporters/default.ts b/packages/vitest/src/node/reporters/default.ts
@@ -22,7 +22,7 @@ export class DefaultReporter extends BaseReporter {
       ...options,
     }
 
-    if (!this.isTTY) {
+    if (!this.isTTY || this.isAgent) {
       this.options.summary = false
     }
 
@@ -32,7 +32,10 @@ export class DefaultReporter extends BaseReporter {
   }
 
   onTestRunStart(specifications: ReadonlyArray<TestSpecification>): void {
-    if (this.isTTY) {
+    if (this.isAgent) {
+      this.renderSucceed = false
+    }
+    else if (this.isTTY) {
       if (this.renderSucceed === undefined) {
         this.renderSucceed = !!this.renderSucceed
       }
diff --git a/packages/vitest/src/node/reporters/utils.ts b/packages/vitest/src/node/reporters/utils.ts
@@ -37,30 +37,34 @@ function createReporters(
   ctx: Vitest,
 ): Promise<Array<Reporter | DefaultReporter | BlobReporter | DotReporter | JsonReporter | TapReporter | JUnitReporter | HangingProcessReporter | GithubActionsReporter>> {
   const runner = ctx.runner
+  const isAgent = !!ctx.config.env?.AI_AGENT
   const promisedReporters = reporterReferences.map(
     async (referenceOrInstance) => {
       if (Array.isArray(referenceOrInstance)) {
         const [reporterName, reporterOptions] = referenceOrInstance
+        const options = isAgent && reporterName in ReportersMap && (reporterOptions as any)?.isAgent == null
+          ? { ...reporterOptions, isAgent: true }
+          : reporterOptions
 
         if (reporterName === 'html') {
           await ctx.packageInstaller.ensureInstalled('@vitest/ui', ctx.config.root, ctx.version)
           const CustomReporter = await loadCustomReporterModule(
             '@vitest/ui/reporter',
             runner,
           )
-          return new CustomReporter(reporterOptions)
+          return new CustomReporter(options)
         }
         else if (reporterName in ReportersMap) {
           const BuiltinReporter
             = ReportersMap[reporterName as BuiltinReporters]
-          return new BuiltinReporter(reporterOptions)
+          return new BuiltinReporter(options)
         }
         else {
           const CustomReporter = await loadCustomReporterModule(
             reporterName,
             runner,
           )
-          return new CustomReporter(reporterOptions)
+          return new CustomReporter(options)
         }
       }
 
diff --git a/packages/vitest/src/utils/env.ts b/packages/vitest/src/utils/env.ts
@@ -12,4 +12,25 @@ export const isDeno: boolean
 export const isWindows: boolean = (isNode || isDeno) && process.platform === 'win32'
 export const isBrowser: boolean = typeof window !== 'undefined'
 export const isTTY: boolean = ((isNode || isDeno) && process.stdout?.isTTY && !isCI)
+export function detectAgent(): boolean {
+  if (!(isNode || isDeno)) {
+    return false
+  }
+  const env = process.env
+  if (env.AI_AGENT === '0' || env.AI_AGENT === 'false') {
+    return false
+  }
+  return !!(
+    env.AI_AGENT
+    || env.CURSOR_TRACE_ID
+    || env.CURSOR_AGENT
+    || env.GEMINI_CLI
+    || env.CODEX_SANDBOX
+    || env.AUGMENT_AGENT
+    || env.OPENCODE_CLIENT
+    || env.CLAUDECODE
+    || env.CLAUDE_CODE
+    || env.REPL_ID
+  )
+}
 export { isCI, provider as stdProvider } from 'std-env'
diff --git a/test/cli/test/reporters/default.test.ts b/test/cli/test/reporters/default.test.ts
@@ -299,4 +299,101 @@ describe('default reporter', async () => {
     })
     expect(stderr).toMatchSnapshot()
   })
+
+  describe('agent mode', () => {
+    test('hides passed module headers and shows only failed tests', async () => {
+      const { stdout } = await runVitest({
+        include: ['b1.test.ts', 'b2.test.ts'],
+        root: 'fixtures/reporters/default',
+        reporters: [['default', { isAgent: true }]],
+        fileParallelism: false,
+        sequence: {
+          sequencer: StableTestFileOrderSorter,
+        },
+      })
+
+      const output = trimReporterOutput(stdout)
+      expect(output).toMatchInlineSnapshot(`
+        "❯ b1.test.ts (13 tests | 1 failed) [...]ms
+             × b failed test [...]ms
+         ❯ b2.test.ts (13 tests | 1 failed) [...]ms
+             × b failed test [...]ms"
+      `)
+    })
+
+    test('hides all output for passed-only modules', async () => {
+      const { stdout } = await runVitest({
+        include: ['b1.test.ts', 'b2.test.ts'],
+        root: 'fixtures/reporters/default',
+        reporters: [['default', { isAgent: true }]],
+        fileParallelism: false,
+        testNamePattern: 'passed',
+        sequence: {
+          sequencer: StableTestFileOrderSorter,
+        },
+      })
+
+      const output = trimReporterOutput(stdout)
+      expect(output).toMatchInlineSnapshot(`""`)
+    })
+
+    test('still prints end summary', async () => {
+      const { stdout } = await runVitest({
+        include: ['b1.test.ts', 'b2.test.ts'],
+        root: 'fixtures/reporters/default',
+        reporters: [['default', { isAgent: true }]],
+        fileParallelism: false,
+        sequence: {
+          sequencer: StableTestFileOrderSorter,
+        },
+      })
+
+      expect(stdout).toContain('Test Files')
+      expect(stdout).toContain('Tests')
+    })
+
+    test('suppresses console logs from passed tests', async () => {
+      const { stdout } = await runVitest({
+        config: false,
+        include: ['./fixtures/reporters/console-some-failing.test.ts'],
+        reporters: [['default', { isAgent: true, isTTY: true }]],
+      })
+
+      expect(stdout).not.toContain('Log from passed test')
+      expect(stdout).not.toContain('Log from passed suite')
+    })
+
+    test('shows console logs from failed tests', async () => {
+      const { stdout } = await runVitest({
+        config: false,
+        include: ['./fixtures/reporters/console-some-failing.test.ts'],
+        reporters: [['default', { isAgent: true, isTTY: true }]],
+      })
+
+      expect(stdout).toContain('Log from failed test')
+      expect(stdout).toContain('Log from failed suite')
+      expect(stdout).toContain('Log from failed file')
+    })
+
+    test('activates via AI_AGENT env config', async () => {
+      const { stdout } = await runVitest({
+        include: ['b1.test.ts', 'b2.test.ts'],
+        root: 'fixtures/reporters/default',
+        reporters: ['default'],
+        fileParallelism: false,
+        env: { AI_AGENT: '1' },
+        sequence: {
+          sequencer: StableTestFileOrderSorter,
+        },
+      })
+
+      const output = trimReporterOutput(stdout)
+      expect(output).toMatchInlineSnapshot(`
+        "❯ b1.test.ts (13 tests | 1 failed) [...]ms
+             × b failed test [...]ms
+         ❯ b2.test.ts (13 tests | 1 failed) [...]ms
+             × b failed test [...]ms"
+      `)
+    })
+  })
 }, 120000)
diff --git a/test/test-utils/index.ts b/test/test-utils/index.ts
@@ -172,6 +172,7 @@ export async function runVitest(
       ...cliOptions,
       env: {
         NO_COLOR: 'true',
+        AI_AGENT: '',
         ...rest.env,
         ...cliOptions?.env,
       },
@@ -281,7 +282,13 @@ async function runCli(command: 'vitest', _options?: CliOptions | string, ...args
     args.push('--maxWorkers=1')
   }
 
-  const subprocess = x(command, args, options as Options).process!
+  const subprocess = x(command, args, {
+    ...options as Options,
+    nodeOptions: {
+      ...(options as Options)?.nodeOptions,
+      env: { ...process.env, AI_AGENT: '0', ...(options as Options)?.nodeOptions?.env },
+    },
+  }).process!
   const cli = new Cli({
     stdin: subprocess.stdin!,
     stdout: subprocess.stdout!,

Original file line number	Diff line number	Diff line change
`@@ -22,7 +22,7 @@ export class DefaultReporter extends BaseReporter {`
`22`	`22`	`...options,`
`23`	`23`	`}`
`24`	`24`
`25`		`- if (!this.isTTY) {`
	`25`	`+ if (!this.isTTY \|\| this.isAgent) {`
`26`	`26`	`this.options.summary = false`
`27`	`27`	`}`
`28`	`28`
`@@ -32,7 +32,10 @@ export class DefaultReporter extends BaseReporter {`
`32`	`32`	`}`
`33`	`33`
`34`	`34`	`onTestRunStart(specifications: ReadonlyArray<TestSpecification>): void {`
`35`		`- if (this.isTTY) {`
	`35`	`+ if (this.isAgent) {`
	`36`	`+ this.renderSucceed = false`
	`37`	`+ }`
	`38`	`+ else if (this.isTTY) {`
`36`	`39`	`if (this.renderSucceed === undefined) {`
`37`	`40`	`this.renderSucceed = !!this.renderSucceed`
`38`	`41`	`}`