itwanger/toBeBetterJavaer · error · Error

Missing value for ${argv[index]}

Error message

Missing value for ${argv[index]}

What it means

Thrown by requireValue() in scripts/sync-sidebar.js when a value-taking option (--sidebar, --route, --dir, --fallback) is last on the command line or its next token starts with '-'. It applies to the space-separated form only; the --option=value form bypasses this check.

Source

Thrown at scripts/sync-sidebar.js:95

      index += 1;
    } else if (arg.startsWith("--fallback=")) {
      options.fallbackGroup = arg.slice("--fallback=".length);
    } else {
      throw new Error(`Unknown option: ${arg}`);
    }
  }

  if ((options.route && !options.dir) || (!options.route && options.dir)) {
    throw new Error("--route and --dir must be used together");
  }

  return options;
}

function requireValue(argv, index) {
  const value = argv[index + 1];
  if (!value || value.startsWith("-")) {
    throw new Error(`Missing value for ${argv[index]}`);
  }
  return value;
}

function normalizeRoute(route) {
  if (!route.startsWith("/")) {
    route = `/${route}`;
  }
  if (!route.endsWith("/")) {
    route = `${route}/`;
  }
  return route;
}

function createTargets(options) {
  if (options.route) {
    return [
      {

View on GitHub (pinned to 6617f5fd0b)

Solutions

1. Add the missing value or switch to the equals form: `--route=/sidebar/itwanger/ai/`
2. Reorder so the value does not sit next to another flag
3. Values beginning with '-' are unsupported in space form — restructure the value

Example fix

# before
node scripts/sync-sidebar.js --sidebar

# after
node scripts/sync-sidebar.js --sidebar=docs/src/.vuepress/sidebar.ts

const VALUE_OPTS = ["--sidebar", "--route", "--dir", "--fallback"];
for (let i = 0; i < args.length; i++) {
  if (VALUE_OPTS.includes(args[i]) && (!args[i + 1] || args[i + 1].startsWith("-"))) {
    throw new Error(`${args[i]} needs a value — use ${args[i]}=value`);
  }
}

catch (err) { if (err.message.startsWith("Missing value for")) { console.error("Use the --option=value form"); process.exit(2); } throw err; }

When it happens

Trigger: `node scripts/sync-sidebar.js --route` as the final token; `--dir --check`; `--fallback -group` where the intended value itself begins with '-'.

Common situations: Truncated shell history entries; flag reordering; values that legitimately start with a dash (rare — routes and dir paths do not).

Related errors

• Unknown option: ${arg}
• Missing value for ${argv[index]}
• Unknown option: ${arg}
• --route and --dir must be used together
• ${optionName} must be a positive integer

AI-assisted analysis of itwanger/toBeBetterJavaer@6617f5fd0b (2026-08-14). Data as JSON: /api/errors/ae9fc0c096607977. Report an issue: GitHub.