fix: encoding

src/commands/js.test.ts

@@ -105,6 +105,19 @@ describe('jsk js — terminal output capture', () => {
     }
   })
 
+  it('strips ANSI color codes from captured terminal output', async () => {
+    // Mirrors what `console.log(42)` writes when the real stdout is a TTY (colors enabled) —
+    // unrelated to whether the output is headed to Discord, so it must be stripped regardless.
+    const { ctx, send } = makeContext('process.stdout.write("\\x1b[33m42\\x1b[39m\\n")')
+
+    await jsCommand.handler(ctx)
+
+    const [payload] = send.mock.calls[0] as [{ content: string }]
+    expect(payload.content).toContain('42')
+    expect(payload.content).not.toContain('\x1b')
+    expect(payload.content).not.toContain('[33m')
+  })
+
   it('does not scrub non-token secrets when security mode is off', async () => {
     process.env.JS_TEST_SECRET_KEY_2 = 'another-secret-value-654321'
     try {

src/commands/js.ts

@@ -2,7 +2,7 @@ import vm from 'node:vm'
 import type { Context } from '../context'
 import { installPrototypeGuards, installRestGuard } from '../prototype-guard'
 import { guardOutbound } from '../security'
-import { inspectResult } from '../util/format'
+import { inspectResult, stripAnsi } from '../util/format'
 import { loadLibraryModule } from '../util/meta'
 import type { Command } from './registry'
 
@@ -184,7 +184,11 @@ function captureTerminalOutput(scrub: ((text: string) => string) | null): {
           : Buffer.isBuffer(chunk)
             ? chunk.toString('utf-8')
             : String(chunk)
-      chunks.push(text)
+      // Stripped for the Discord-bound capture only — colors are decided by whether the
+      // *real* stdout/stderr is a TTY, which has nothing to do with whether this is headed to
+      // Discord (not a terminal), so raw escape codes would otherwise show up as literal
+      // garbage (see stripAnsi's doc comment). The real stream output is left untouched.
+      chunks.push(stripAnsi(text))
       const outgoing = scrub ? scrub(text) : chunk
       // biome-ignore lint/suspicious/noExplicitAny: forwarding Node's overloaded write(chunk, encoding?, callback?) verbatim.
       return (original as any).apply(stream, [outgoing, ...rest])

src/util/format.ts

@@ -13,6 +13,24 @@ export const MAX_PAGINATED_PAGES = 10
 /** Zero-width space used to defuse backtick sequences inside codeblocks. */
 const ZWSP = '​'
 
+// Matches ANSI escape sequences (colors, cursor movement, etc.).
+// biome-ignore lint/suspicious/noControlCharactersInRegex: intentional — stripping terminal control codes.
+const ANSI_ESCAPE = /\x1b\[[0-9;?]*[A-Za-z]/g
+
+/**
+ * Strips ANSI escape sequences (colors, cursor movement, ...) from `text`.
+ *
+ * Discord code blocks aren't a real terminal, so raw escape codes just show up as visible
+ * garbage (e.g. `console.log(42)` under a color-capable stdout emits `\x1b[33m42\x1b[39m`,
+ * which renders as literal `[33m42[39m` once the non-printable ESC byte is gone). Node's
+ * `console`/`util.inspect` decide whether to colorize based on whether the *real* stdout/stderr
+ * is a TTY — which has nothing to do with whether the output is actually headed to Discord —
+ * so captured terminal output always needs this before being sent, regardless of environment.
+ */
+export function stripAnsi(text: string): string {
+  return text.replace(ANSI_ESCAPE, '')
+}
+
 /**
  * Represents a raw file attachment payload accepted by both discord.js v13 and v14
  * (`{ attachment, name }`), avoiding version-specific builder classes.

src/util/shell-reader.ts

@@ -1,14 +1,11 @@
 import { type ChildProcessWithoutNullStreams, spawn } from 'node:child_process'
 import { existsSync } from 'node:fs'
 import type { Encoding, ShellOverride } from '../types'
+import { stripAnsi } from './format'
 
 const WINDOWS = process.platform === 'win32'
 const POWERSHELL = 'C:\\Windows\\System32\\WindowsPowerShell\\v1.0\\powershell.exe'
 
-// Matches ANSI escape sequences (colors, cursor movement, etc.).
-// biome-ignore lint/suspicious/noControlCharactersInRegex: intentional — stripping terminal control codes.
-const ANSI_ESCAPE = /\x1b\[[0-9;?]*[A-Za-z]/g
-
 const ZWSP = '​'
 
 function toDecoderLabel(encoding: Encoding): string {
@@ -39,7 +36,7 @@ function cmdCodepage(label: string): number {
 }
 
 function cleanLine(line: string): string {
-  return line.replace(ANSI_ESCAPE, '').replace('\r', '').replaceAll('```', `\`\`${ZWSP}\``)
+  return stripAnsi(line).replace('\r', '').replaceAll('```', `\`\`${ZWSP}\``)
 }
 
 export interface ShellReaderOptions {