Yeachan-Heo/oh-my-codex · error

${path} must be a non-empty string array

Error message

${path} must be a non-empty string array

What it means

validateStringArray requires an array where every element is a non-empty, non-whitespace string. It is used to validate answer.selected_values and answer.selected_labels on submitted question answers; anything else (non-array, empty array elements, blanks, numbers) throws with the offending path.

Source

Thrown at src/question/state.ts:298

    }
  }

  try {
    return await fn();
  } finally {
    try {
      const currentOwner = await readFile(ownerPath, 'utf8');
      if (currentOwner.trim() === ownerToken) {
        await rm(lockDir, { recursive: true, force: true });
      }
    } catch {
    }
  }
}

function validateStringArray(value: unknown, path: string): string[] {
  if (!Array.isArray(value) || !value.every((item) => typeof item === 'string' && item.trim().length > 0)) {
    throw new Error(`${path} must be a non-empty string array`);
  }
  return value;
}

function assertNoDuplicateValues(values: string[], path: string): void {
  const seen = new Set<string>();
  for (const value of values) {
    if (seen.has(value)) throw new Error(`${path} must not contain duplicate values: ${value}`);
    seen.add(value);
  }
}

function expectedSelectedLabelsForValues(
  question: NormalizedQuestionItem,
  selectedValues: string[],
  otherText: string | undefined,
): string[] {
  const optionLabelsByValue = new Map(question.options.map((option) => [option.value, option.label]));

View on GitHub (pinned to 3ad79a8a6f)

Solutions

1. Ensure selected_values and selected_labels are always arrays of trimmed, non-empty strings before submit
2. Filter out empty/blank entries: values.map(v => v.trim()).filter(Boolean)
3. Add a client-side schema check (e.g. zod) mirroring: array of non-empty strings

Example fix

// before
answer.selected_values = rawInput; // could be '' or undefined
// after
answer.selected_values = (Array.isArray(rawInput) ? rawInput : [rawInput]).map((v) => String(v).trim()).filter((v) => v.length > 0);

function isNonEmptyStringArray(v: unknown): v is string[] {
  return Array.isArray(v) && v.every((x) => typeof x === 'string' && x.trim().length > 0);
}
if (!isNonEmptyStringArray(answer.selected_values)) throw new Error('bad selected_values');

function isNonEmptyStringArray(v: unknown): v is string[] {
  return Array.isArray(v) && v.every((x) => typeof x === 'string' && x.trim().length > 0);
}

try { await submit(recordPath, answers); } catch (e) { if (/must be a non-empty string array/.test((e as Error).message)) { highlightInvalidField((e as Error).message); return; } throw e; }

When it happens

Trigger: Submitting an answer whose selected_values or selected_labels is undefined, not an array, contains empty strings, whitespace-only strings, or non-string values; e.g. answers[i].answer.selected_values = [] is fine only if length checks elsewhere pass, but [''] or 'opt1' (a bare string) throw here.

Common situations: Clients building answers from raw form state without normalizing empty inputs; JSON payloads where a single select sends a scalar instead of a 1-element array; trimming side effects producing '' after whitespace-only input.

Understand the failure class

Background: Schema validation failed / invalid input schema: payload rejected because its shape doesn't match the expected schema — this error's family across 28 libraries.

Related errors

• selected value is not in the option schema: ${value}
• ${path} cardinality must match selected values
• ${path}[${mismatchIndex}] must match the selected value labe
• answers[${entry.index}].question_id is unknown for this ques
• answers[${entry.index}].answer.kind=other is not allowed for

AI-assisted analysis of Yeachan-Heo/oh-my-codex@3ad79a8a6f (2026-08-27). Data as JSON: /api/errors/ff9277b6480d0e2a. Report an issue: GitHub.