Function formatFpsParseError

packages/cli/src/commands/render.ts:104–122

* Map a FpsParseResult failure reason to a human-friendly * error-box message. The empty / undefined / default-fallthrough case * shouldn't be reachable from the CLI flag (citty supplies a default of * "30") but the branch exists so this helper can be reused by other * fps-accepting CLI

(
  input: string,
  reason: Exclude<FpsParseResult, { ok: true }>["reason"],
)

 * fps-accepting CLI surfaces in the future.
 */
function formatFpsParseError(
  input: string,
  reason: Exclude<FpsParseResult, { ok: true }>["reason"],
): string {
  switch (reason) {
    case "empty":
      return "Frame rate must not be empty.";
    case "not-a-number":
      return `Got "${input}". Frame rate must be an integer (e.g. 30) or a rational (e.g. 30000/1001 for NTSC).`;
    case "non-positive":
      return `Got "${input}". Frame rate must be greater than zero.`;
    case "out-of-range":
      return `Got "${input}". Frame rate must be in the range 1–240.`;
    case "invalid-fraction":
      return `Got "${input}". Rational frame rates must be two positive integers separated by '/' (e.g. 30000/1001).`;
    case "ambiguous-decimal":
      return `Got "${input}". Decimal frame rates are ambiguous — use the exact rational form instead (e.g. 30000/1001 for 29.97).`;
  }
}
const RENDER_FORMATS = ["mp4", "webm", "mov", "png-sequence", "gif"] as const;
type RenderFormat = (typeof RENDER_FORMATS)[number];
const VALID_FORMAT = new Set<string>(RENDER_FORMATS);