What causes "Invalid value for --${name}: ${raw}" in chenglou/pretext?

Use plain integers: --port=0, --timeout=60000 (milliseconds).

chenglou/pretext · error · Error

Invalid value for --${name}: ${raw}

Error message

Invalid value for --${name}: ${raw}

What it means

Identical helper shape to error 81, here in scripts/symbol-check.ts. parseNumberFlag guards --port (line 77) and --timeout (line 79, default 60000). Throws when Number.parseInt(raw, 10) is NaN. Called at module top-level, so it aborts before any browser automation starts. Note parseInt tolerates surrounding whitespace, so '8080 ' is fine, but '8080px' throws.

Source

Thrown at scripts/symbol-check.ts:55

  requestId?: string
  results?: Array<{
    label: string
    report: ProbeReport
  }>
  message?: string
}

function parseStringFlag(name: string): string | null {
  const prefix = `--${name}=`
  const arg = process.argv.find(value => value.startsWith(prefix))
  return arg === undefined ? null : arg.slice(prefix.length)
}

function parseNumberFlag(name: string, fallback: number): number {
  const raw = parseStringFlag(name)
  if (raw === null) return fallback
  const parsed = Number.parseInt(raw, 10)
  if (!Number.isFinite(parsed)) throw new Error(`Invalid value for --${name}: ${raw}`)
  return parsed
}

function parseBrowsers(value: string | null): AutomationBrowserKind[] {
  const raw = (value ?? 'chrome,safari').trim()
  if (raw.length === 0) return ['chrome', 'safari']

  const browsers = raw
    .split(',')
    .map(part => part.trim().toLowerCase())
    .filter(Boolean)

  for (const browser of browsers) {
    if (browser !== 'chrome' && browser !== 'safari' && browser !== 'firefox') {
      throw new Error(`Unsupported browser ${browser}`)
    }
  }

View on GitHub (pinned to ac49b09b7d)

Solutions

Use plain integers: --port=0, --timeout=60000 (milliseconds).
Remember --timeout is milliseconds, not seconds.
The message names the bad flag and shows the raw value.

Example fix

# before
bun run scripts/symbol-check.ts --timeout=30s

# after
bun run scripts/symbol-check.ts --timeout=30000

Defensive patterns

Strategy: validation

Validate before calling

const isIntFlag = (raw: string | null): boolean =>
  raw === null || /^-?\d+$/.test(raw.trim())
for (const name of ['port', 'timeout'] as const) {
  const raw = parseStringFlag(name)
  if (!isIntFlag(raw)) {
    console.error(`--${name} expects an integer (ms for timeout), got ${JSON.stringify(raw)}`)
    process.exit(2)
  }
}

Type guard

const isIntFlag = (s: string | null): s is string =>
  s !== null && Number.isFinite(Number.parseInt(s, 10))

Prevention

--timeout is milliseconds; --port is unitless. Never append units like 's' or 'px'.
Validate before launch since these flags are read at module top-level and abort early.

When it happens

Trigger: --port=abc; --timeout=10s; --port= (empty). --timeout is milliseconds, so '30s' is a common mistake.

Common situations: Copy-pasting units into --timeout (30s instead of 30000); empty --port=; forgetting --timeout is in ms.

Related errors

AI-assisted analysis of chenglou/pretext@ac49b09b7d (2026-08-12). Data as JSON: /api/errors/98bdf2cb203648de. Report an issue: GitHub.