fix: stderr tokens are no longer injected when in development mode (#32674)

* do not tag streams when in dev mode, or when electron_enable_logging is true

* test negative of ELECTRON_ENABLE_LOGGING

* changelog

* refactor / better structuring of tag enable/disable

* improvement

* changelog

* flush with an empty buffer if there is nothing left in the decoder

* make flush / transform consistent w/ empty output

Author: cacieprins

cli/CHANGELOG.md

@@ -10,6 +10,7 @@ _Released 10/21/2025 (PENDING)_
 **Bugfixes:**
 
 - An error is no longer thrown during command execution when the application under test overwrites the `window.$` property with a non-function. Fixes [#1502](https://github.com/cypress-io/cypress/issues/1502). Fixed in [#32682](https://github.com/cypress-io/cypress/pull/32682).
+- When running `cypress` in Cypress development environments, or when `ELECTRON_ENABLE_LOGGING` is otherwise set to 1, certain messages written to `stderr` will no longer be bracketed with verbose tags. Addresses [#32569](https://github.com/cypress-io/cypress/issues/32569). Addressed in [#32674](https://github.com/cypress-io/cypress/pull/32674).
 
 **Misc:**
 

packages/stderr-filtering/lib/Filter.ts

@@ -4,17 +4,17 @@ import { START_TAG, END_TAG } from './constants'
 import { FilterPrefixedContent } from './FilterPrefixedContent'
 import { FilterTaggedContent } from './FilterTaggedContent'
 import { WriteToDebug } from './WriteToDebug'
+import { tagsDisabled } from './tagsDisabled'
 
-const DISABLE_TAGS = process.env.ELECTRON_ENABLE_LOGGING === '1'
-
-export function filter (stderr: Writable, debug: Debugger, prefix: RegExp, disableTags: boolean = false): Writable {
+export function filter (stderr: Writable, debug: Debugger, prefix: RegExp): Writable {
   const prefixTx = new FilterPrefixedContent(prefix, stderr)
-  const tagTx = new FilterTaggedContent(START_TAG, END_TAG, stderr)
   const debugWriter = new WriteToDebug(debug)
 
-  if (DISABLE_TAGS || disableTags) {
+  if (tagsDisabled()) {
     prefixTx.pipe(debugWriter)
   } else {
+    const tagTx = new FilterTaggedContent(START_TAG, END_TAG, stderr)
+
     prefixTx.pipe(tagTx).pipe(debugWriter)
   }
 

packages/stderr-filtering/lib/TagStream.ts

@@ -2,8 +2,10 @@ import { Transform } from 'stream'
 import { START_TAG, END_TAG } from './constants'
 import { StringDecoder } from 'string_decoder'
 import Debug from 'debug'
+import { tagsDisabled } from './tagsDisabled'
 
 const debug = Debug('cypress:stderr-filtering:TagStream')
+const debugVerbose = Debug('cypress-verbose:stderr-filtering:TagStream')
 
 /**
  * A Transform stream that wraps input data with start and end tags.
@@ -66,13 +68,13 @@ export class TagStream extends Transform {
       const out = chunk instanceof Buffer ?
         this.initializedDecoder.write(chunk) :
         chunk
-      const transformed = `${this.startTag}${out}${this.endTag}`
+      const transformed = out ? this.tag(out) : Buffer.from('')
 
-      debug(`transformed: "${transformed.replaceAll('\n', '\\n')}"`)
-      const canWrite = this.push(out ? Buffer.from(transformed) : '')
+      debugVerbose(`transformed: "${transformed.toString().replaceAll('\n', '\\n')}"`)
+      const canWrite = this.push(transformed)
 
       if (!canWrite) {
-        debug('waiting for drain')
+        debugVerbose('waiting for drain')
         await new Promise((resolve) => this.once('drain', resolve))
       }
 
@@ -95,6 +97,10 @@ export class TagStream extends Transform {
     debug('flushing')
     const out = this.initializedDecoder.end()
 
-    callback(undefined, Buffer.from(`${this.startTag}${out}${this.endTag}`))
+    callback(undefined, out ? this.tag(out) : Buffer.from(''))
+  }
+
+  private tag (str: string): Buffer {
+    return tagsDisabled() ? Buffer.from(str) : Buffer.from(`${this.startTag}${str}${this.endTag}`)
   }
 }

packages/stderr-filtering/lib/__spec__/Filter.spec.ts

@@ -10,9 +10,6 @@ vi.mock('../FilterPrefixedContent')
 vi.mock('../FilterTaggedContent')
 vi.mock('../WriteToDebug')
 
-// Mock process.env
-const originalEnv = process.env
-
 describe('Filter', () => {
   let mockStderr: any
   let mockDebug: any
@@ -21,9 +18,6 @@ describe('Filter', () => {
   let mockWriteToDebug: any
 
   beforeEach(() => {
-    // Reset environment
-    process.env = { ...originalEnv }
-
     // Create mock objects
     mockStderr = {
       write: vi.fn(),
@@ -54,48 +48,38 @@ describe('Filter', () => {
 
   afterEach(() => {
     vi.clearAllMocks()
-    process.env = originalEnv
+    vi.unstubAllEnvs()
   })
 
-  describe('when disableTags is false', () => {
-    beforeEach(() => {
-      process.env.ELECTRON_ENABLE_LOGGING = '0'
-    })
-
+  describe('when tags are enabled', () => {
     it('pipes prefixTx -> tagTx -> debugWriter', () => {
-      const result = filter(mockStderr, mockDebug, DEBUG_PREFIX, false)
+      vi.stubEnv('ELECTRON_ENABLE_LOGGING', '0')
+      vi.stubEnv('CYPRESS_INTERNAL_ENV', 'production')
+
+      const result = filter(mockStderr, mockDebug, DEBUG_PREFIX)
 
-      // Verify FilterPrefixedContent was created with correct args
       expect(FilterPrefixedContent).toHaveBeenCalledWith(DEBUG_PREFIX, mockStderr)
 
-      // Verify FilterTaggedContent was created with correct args
       expect(FilterTaggedContent).toHaveBeenCalledWith(START_TAG, END_TAG, mockStderr)
 
-      // Verify WriteToDebug was created with correct args
       expect(WriteToDebug).toHaveBeenCalledWith(mockDebug)
 
-      // Verify the pipe chain: prefixTx -> tagTx -> debugWriter
       expect(mockFilterPrefixedContent.pipe).toHaveBeenCalledWith(mockFilterTaggedContent)
       expect(mockFilterTaggedContent.pipe).toHaveBeenCalledWith(mockWriteToDebug)
 
-      // Verify the result is the prefixTx
       expect(result).toBe(mockFilterPrefixedContent)
     })
   })
 
-  describe('when disableTags parameter is true', () => {
-    beforeEach(() => {
-      process.env.ELECTRON_ENABLE_LOGGING = '0'
-    })
-
-    it('should pipe prefixTx -> debugWriter (skip tagTx)', () => {
-      const result = filter(mockStderr, mockDebug, DEBUG_PREFIX, true)
+  describe('disabling tags', () => {
+    function expectNoTags () {
+      const result = filter(mockStderr, mockDebug, DEBUG_PREFIX)
 
       // Verify FilterPrefixedContent was created with correct args
       expect(FilterPrefixedContent).toHaveBeenCalledWith(DEBUG_PREFIX, mockStderr)
 
       // Verify FilterTaggedContent was created with correct args
-      expect(FilterTaggedContent).toHaveBeenCalledWith(START_TAG, END_TAG, mockStderr)
+      expect(FilterTaggedContent).not.toHaveBeenCalled()
 
       // Verify WriteToDebug was created with correct args
       expect(WriteToDebug).toHaveBeenCalledWith(mockDebug)
@@ -106,6 +90,16 @@ describe('Filter', () => {
 
       // Verify the result is the prefixTx
       expect(result).toBe(mockFilterPrefixedContent)
+    }
+
+    it('does not add tags when ELECTRON_ENABLE_LOGGING is enabled', () => {
+      vi.stubEnv('ELECTRON_ENABLE_LOGGING', '1')
+      expectNoTags()
+    })
+
+    it('does not add tags when CYPRESS_INTERNAL_ENV is development', () => {
+      vi.stubEnv('CYPRESS_INTERNAL_ENV', 'development')
+      expectNoTags()
     })
   })
 })

packages/stderr-filtering/lib/__spec__/TagStream.spec.ts

@@ -93,7 +93,7 @@ describe('TagStream', () => {
         const cb = vi.fn()
 
         await tagStream.transform(bufInput, 'buffer', cb)
-        expect(tagStream.push).toHaveBeenCalledWith('')
+        expect(tagStream.push).toHaveBeenCalledWith(Buffer.from(''))
         expect(cb).toHaveBeenCalled()
       })
     })
@@ -115,4 +115,63 @@ describe('TagStream', () => {
       })
     })
   })
+
+  describe('disabling tags', () => {
+    afterEach(() => {
+      vi.unstubAllEnvs()
+    })
+
+    it('passes on the string without the tags in CYPRESS_INTERNAL_ENV development mode', async () => {
+      vi.stubEnv('CYPRESS_INTERNAL_ENV', 'development')
+      const cb = vi.fn()
+
+      await tagStream.transform(strInput, 'utf-8', cb)
+      expect(tagStream.push).toHaveBeenCalledWith(Buffer.from(strInput))
+      expect(cb).toHaveBeenCalled()
+    })
+
+    describe('when ELECTRON_ENABLE_LOGGING is enabled', () => {
+      beforeEach(() => {
+        vi.stubEnv('ELECTRON_ENABLE_LOGGING', '1')
+      })
+
+      it('does not add the tags when transforming', async () => {
+        const cb = vi.fn()
+
+        await tagStream.transform(strInput, 'utf-8', cb)
+        expect(tagStream.push).toHaveBeenCalledWith(Buffer.from(strInput))
+        expect(cb).toHaveBeenCalled()
+      })
+
+      it('does not add the tags when flushing', async () => {
+        const cb = vi.fn()
+
+        mockStringDecoder.end.mockReturnValue(strInput)
+        await tagStream.flush(cb)
+        expect(cb).toHaveBeenCalledWith(undefined, Buffer.from(strInput))
+      })
+    })
+
+    describe('when CYPRESS_INTERNAL_ENV is development', () => {
+      beforeEach(() => {
+        vi.stubEnv('CYPRESS_INTERNAL_ENV', 'development')
+      })
+
+      it('does not add the tags when transforming', async () => {
+        const cb = vi.fn()
+
+        await tagStream.transform(strInput, 'utf-8', cb)
+        expect(tagStream.push).toHaveBeenCalledWith(Buffer.from(strInput))
+        expect(cb).toHaveBeenCalled()
+      })
+
+      it('does not add the tags when flushing', async () => {
+        const cb = vi.fn()
+
+        mockStringDecoder.end.mockReturnValue(strInput)
+        await tagStream.flush(cb)
+        expect(cb).toHaveBeenCalledWith(undefined, Buffer.from(strInput))
+      })
+    })
+  })
 })

packages/stderr-filtering/lib/__spec__/logError.spec.ts

@@ -13,6 +13,7 @@ describe('logError', () => {
   afterEach(() => {
     // Restore the original console.error
     consoleErrorSpy.mockRestore()
+    vi.unstubAllEnvs()
   })
 
   describe('START_TAG and END_TAG constants', () => {
@@ -105,6 +106,22 @@ describe('logError', () => {
       expect(consoleErrorSpy).toHaveBeenCalledTimes(1)
       expect(consoleErrorSpy).toHaveBeenCalledWith(START_TAG, error, END_TAG)
     })
+
+    it('does not add tags in CYPRESS_INTERNAL_ENV development mode', () => {
+      vi.stubEnv('CYPRESS_INTERNAL_ENV', 'development')
+      logError('Test error')
+
+      expect(consoleErrorSpy).toHaveBeenCalledTimes(1)
+      expect(consoleErrorSpy).toHaveBeenCalledWith('Test error')
+    })
+
+    it('does not add tags in ELECTRON_ENABLE_LOGGING enabled', () => {
+      vi.stubEnv('ELECTRON_ENABLE_LOGGING', '1')
+      logError('Test error')
+
+      expect(consoleErrorSpy).toHaveBeenCalledTimes(1)
+      expect(consoleErrorSpy).toHaveBeenCalledWith('Test error')
+    })
   })
 
   describe('integration with console.error', () => {

packages/stderr-filtering/lib/logError.ts

@@ -1,7 +1,8 @@
 /**
- * Standard error logging tags used for stderr filtering.a
+ * Standard error logging tags used for stderr filtering
  */
 import { START_TAG, END_TAG } from './constants'
+import { tagsDisabled } from './tagsDisabled'
 
 /**
  * Logs error messages with special tags for stderr filtering.
@@ -14,12 +15,10 @@ import { START_TAG, END_TAG } from './constants'
  * @param args The arguments to log as an error message
  */
 
-const DISABLE_TAGS = process.env.ELECTRON_ENABLE_LOGGING === '1'
-
 export const logError = (...args: any[]) => {
   // When electron debug is enabled, the output will not be filtered, so
   // these tags are not needed.
-  if (DISABLE_TAGS) {
+  if (tagsDisabled()) {
     // eslint-disable-next-line no-console
     console.error(...args)
   } else {

packages/stderr-filtering/lib/tagsDisabled.ts

@@ -0,0 +1,3 @@
+export function tagsDisabled () {
+  return process.env.ELECTRON_ENABLE_LOGGING === '1' || process.env.CYPRESS_INTERNAL_ENV === 'development'
+}