Strip all ANSI control sequences in bounded terminal output buffer

common/src/util/__tests__/string.test.ts

@@ -1,6 +1,6 @@
 import { describe, expect, it } from 'bun:test'
 
-import { pluralize } from '../string'
+import { pluralize, stripAnsi, stripColors } from '../string'
 
 describe('pluralize', () => {
   it('should handle singular and plural cases correctly', () => {
@@ -53,13 +53,13 @@ describe('pluralize', () => {
     expect(pluralize(2, 'person')).toBe('2 people')
     expect(pluralize(2, 'child')).toBe('2 children')
     expect(pluralize(2, 'mouse')).toBe('2 mice')
-    
+
     // -ex/-ix → -ices (no reliable rule, must be hardcoded)
     expect(pluralize(2, 'index')).toBe('2 indices')
     expect(pluralize(2, 'vertex')).toBe('2 vertices')
     expect(pluralize(2, 'matrix')).toBe('2 matrices')
     expect(pluralize(2, 'appendix')).toBe('2 appendices')
-    
+
     // Latin -um → -a
     expect(pluralize(2, 'datum')).toBe('2 data')
     expect(pluralize(2, 'medium')).toBe('2 media')
@@ -123,7 +123,7 @@ describe('pluralize', () => {
     expect(pluralize(2, 'data')).toBe('2 data')
     expect(pluralize(2, 'metadata')).toBe('2 metadata')
     expect(pluralize(2, 'feedback')).toBe('2 feedback')
-    
+
     // Other words ending in -s that don't change
     expect(pluralize(2, 'series')).toBe('2 series')
     expect(pluralize(2, 'chassis')).toBe('2 chassis')
@@ -135,7 +135,7 @@ describe('pluralize', () => {
     expect(pluralize(2, 'hero')).toBe('2 heroes')
     expect(pluralize(2, 'echo')).toBe('2 echoes')
     expect(pluralize(2, 'veto')).toBe('2 vetoes')
-    
+
     // Tech terms that just add -s
     expect(pluralize(2, 'photo')).toBe('2 photos')
     expect(pluralize(2, 'video')).toBe('2 videos')
@@ -160,11 +160,11 @@ describe('pluralize', () => {
     expect(pluralize(2, 'shelf')).toBe('2 shelves')
     expect(pluralize(2, 'self')).toBe('2 selves')
     expect(pluralize(2, 'leaf')).toBe('2 leaves')
-    
+
     // -fe to -ves
     expect(pluralize(2, 'knife')).toBe('2 knives')
     expect(pluralize(2, 'life')).toBe('2 lives')
-    
+
     // Tech/design terms that just add -s
     expect(pluralize(2, 'proof')).toBe('2 proofs') // mathematical proofs
     expect(pluralize(2, 'brief')).toBe('2 briefs') // design briefs
@@ -237,3 +237,51 @@ describe('pluralize', () => {
   })
 })
 
+describe('stripAnsi', () => {
+  it('strips ANSI color escape sequences', () => {
+    expect(stripAnsi('\u001b[31;1mred text\u001b[0m')).toBe('red text')
+    expect(stripAnsi('\u001b[38;5;196mcolored\u001b[0m normal')).toBe(
+      'colored normal',
+    )
+  })
+
+  it('strips CSI control sequences (line clears, cursor movement, visibility)', () => {
+    expect(stripAnsi('building...\u001b[2K\r')).toBe('building...\r')
+    expect(stripAnsi('\u001b[?25lhidden\u001b[?25h')).toBe('hidden')
+    expect(stripAnsi('\u001b[1A\u001b[2Jcleared')).toBe('cleared')
+  })
+
+  it('strips OSC sequences terminated by BEL (\\u0007)', () => {
+    expect(stripAnsi('\u001b]0;my window title\u0007window')).toBe('window')
+    expect(stripAnsi('prefix\u001b]2;tab title\u0007suffix')).toBe(
+      'prefixsuffix',
+    )
+  })
+
+  it('strips OSC sequences terminated by String Terminator (ST, ESC \\)', () => {
+    expect(stripAnsi('\u001b]0;my window title\u001b\\window')).toBe('window')
+    expect(stripAnsi('prefix\u001b]2;tab title\u001b\\suffix')).toBe(
+      'prefixsuffix',
+    )
+  })
+
+  it('strips 2-character Fe escape sequences', () => {
+    expect(stripAnsi('\u001bMreverse index')).toBe('reverse index')
+    expect(stripAnsi('\u001bNsingle shift 2')).toBe('single shift 2')
+  })
+
+  it('preserves plain text without escape sequences', () => {
+    expect(stripAnsi('hello world 123 !@#$%^&*()')).toBe(
+      'hello world 123 !@#$%^&*()',
+    )
+  })
+})
+
+describe('stripColors', () => {
+  it('strips only ANSI color codes while leaving other sequences alone', () => {
+    expect(stripColors('\u001b[31mred\u001b[0m')).toBe('red')
+    expect(stripColors('status: \u001b[2K\rline')).toBe(
+      'status: \u001b[2K\rline',
+    )
+  })
+})

common/src/util/string.ts

@@ -378,7 +378,8 @@ export function stripColors(str: string): string {
   return str.replace(ansiColorsRegex, '')
 }
 
-const ansiRegex = /\x1B(?:[@-Z\\-_]|\[[0-?]*[ -/]*[@-~]|\][^\x1B]*\x1B\\?)/g
+const ansiRegex =
+  /\x1B(?:\[[0-?]*[ -/]*[@-~]|\][^\x07\x1B]*(?:\x07|\x1B\\)|[@-Z\\-_])/g
 export function stripAnsi(str: string): string {
   return str.replace(ansiRegex, '')
 }

sdk/src/__tests__/run-terminal-command.test.ts

@@ -109,6 +109,51 @@ describe('BoundedOutputBuffer', () => {
     expect(output.format()).toStartWith('chunk-0000')
     expect(output.format()).toEndWith('chunk-0999')
   })
+
+  test('strips non-color ANSI control sequences such as line clears and cursor controls', () => {
+    const output = new BoundedOutputBuffer(100)
+    output.append('building...\u001b[2K\r')
+    output.append('\u001b[?25lprogress\u001b[?25h')
+    output.append('\u001b[1A\u001b[2Jdone')
+
+    expect(output.format()).toBe('building...\rprogressdone')
+    expect(output.format()).not.toContain('\u001b[')
+  })
+
+  test('strips fully-terminated OSC sequences and preserves trailing text', () => {
+    const output = new BoundedOutputBuffer(100)
+    // OSC sequence terminated by BEL with text after it in same chunk
+    output.append('building...\u001b]0;my window title\u0007done')
+    // OSC sequence terminated by String Terminator (ST, ESC \)
+    output.append(' \u001b]2;another title\u001b\\completed')
+    // OSC sequence terminated by BEL as the final chunk
+    output.append('\u001b]0;final title\u0007')
+
+    expect(output.format()).toBe('building...done completed')
+    expect(output.format()).not.toContain('\u001b]')
+    expect(output.format()).not.toContain('my window title')
+    expect(output.format()).not.toContain('another title')
+    expect(output.format()).not.toContain('final title')
+  })
+
+  test('buffers and strips split ANSI control sequences across chunk boundaries', () => {
+    const output = new BoundedOutputBuffer(100)
+    // Split CSI
+    output.append('step 1\u001b[2')
+    output.append('K-cleared')
+    output.append(' \u001b[?25')
+    output.append('h-visible')
+    // Split OSC across chunks terminated by BEL
+    output.append(' \u001b]0;tit')
+    output.append('le\u0007-osc-bel')
+    // Split OSC across chunks terminated by ST split between ESC and backslash
+    output.append(' \u001b]0;title2\u001b')
+    output.append('\\-osc-st')
+
+    expect(output.format()).toBe('step 1-cleared -visible -osc-bel -osc-st')
+    expect(output.format()).not.toContain('\u001b[')
+    expect(output.format()).not.toContain('\u001b]')
+  })
 })
 
 describe('terminal command process diagnostics', () => {

sdk/src/tools/run-terminal-command.ts

@@ -8,19 +8,17 @@ import type {
 } from 'child_process'
 import type { Readable } from 'stream'
 
-import { stripColors } from '../../../common/src/util/string'
+import { stripAnsi } from '../../../common/src/util/string'
 import { getSystemProcessEnv } from '../env'
-import {
-  createWindowsBashNotFoundError,
-  findWindowsBash,
-} from './windows-bash'
+import { createWindowsBashNotFoundError, findWindowsBash } from './windows-bash'
 
 import type { CodebuffToolOutput } from '../../../common/src/tools/list'
 
 const COMMAND_OUTPUT_LIMIT = 50_000
 const TRUNCATION_MARKER = '\n[...TRUNCATED DUE TO LENGTH...]\n'
-const MAX_PENDING_COLOR_SEQUENCE_LENGTH = 32
-const INCOMPLETE_COLOR_SEQUENCE_REGEX = /\x1B\[[0-9;]*$/
+const MAX_PENDING_ESCAPE_SEQUENCE_LENGTH = 32
+const INCOMPLETE_ESCAPE_SEQUENCE_REGEX =
+  /\x1B(?:\[[0-?]*[ -/]*|\][^\x07\x1B]*(?:\x1B)?)?$/
 // Grace period between SIGTERM and SIGKILL for commands that trap or ignore
 // SIGTERM.
 const KILL_ESCALATION_MS = 1500
@@ -64,7 +62,7 @@ export class BoundedOutputBuffer {
   private head = ''
   private tail = ''
   private truncated = false
-  private pendingColorSequence = ''
+  private pendingEscapeSequence = ''
   private readonly headLimit: number
   private readonly tailLimit: number
 
@@ -80,19 +78,19 @@ export class BoundedOutputBuffer {
   append(value: string): void {
     if (!value) return
 
-    let normalized = this.pendingColorSequence + value
-    this.pendingColorSequence = ''
-    const incompleteColorSequence = normalized.match(
-      INCOMPLETE_COLOR_SEQUENCE_REGEX,
+    let normalized = this.pendingEscapeSequence + value
+    this.pendingEscapeSequence = ''
+    const incompleteEscapeSequence = normalized.match(
+      INCOMPLETE_ESCAPE_SEQUENCE_REGEX,
     )?.[0]
     if (
-      incompleteColorSequence &&
-      incompleteColorSequence.length <= MAX_PENDING_COLOR_SEQUENCE_LENGTH
+      incompleteEscapeSequence &&
+      incompleteEscapeSequence.length <= MAX_PENDING_ESCAPE_SEQUENCE_LENGTH
     ) {
-      this.pendingColorSequence = incompleteColorSequence
-      normalized = normalized.slice(0, -incompleteColorSequence.length)
+      this.pendingEscapeSequence = incompleteEscapeSequence
+      normalized = normalized.slice(0, -incompleteEscapeSequence.length)
     }
-    normalized = stripColors(normalized)
+    normalized = stripAnsi(normalized)
     if (!normalized) return
 
     if (!this.truncated) {