Function resolveBuiltinWithFallback

src/utils/ripgrep.ts:77–117

(
  builtinPath: string,
  systemRgPath?: string | null,
  platform?: string,
)

 * @param platform     Override for `process.platform` (tests only).
 */
export function resolveBuiltinWithFallback(
  builtinPath: string,
  systemRgPath?: string | null,
  platform?: string,
): {
  mode: 'system' | 'builtin'
  command: string
  args: string[]
  note?: string
} {
  const p = platform ?? process.platform

  // Builtin exists — use it, no note.
  if (existsSync(builtinPath)) {
    return { mode: 'builtin', command: builtinPath, args: [] }
  }

  // Builtin missing — check system rg.
  // When systemRgPath is explicitly passed (including null), use it directly.
  // When undefined, call findExecutable (production path).
  const resolvedSystem =
    systemRgPath === undefined
      ? findExecutable('rg', []).cmd
      : (systemRgPath ?? 'rg')
  if (resolvedSystem !== 'rg') {
    return {
      mode: 'system',
      command: 'rg',
      args: [],
      note: `fallback: builtin rg unavailable on ${p}, using system rg`,
    }
  }

  // Neither available.
  return {
    mode: 'builtin',
    command: builtinPath,
    args: [],
    note: `no ripgrep available on ${p}; install ripgrep via apt/pkg/brew`,
  }
}

export function ripgrepCommand(): {
  rgPath: string