pbakaus/impeccable · error · Error

config.insertBefore or config.insertAfter (string) required

Error message

config.insertBefore or config.insertAfter (string) required

What it means

Sixth validateConfig() check: at least one of cfg.insertBefore or cfg.insertAfter must be a string. These are the anchor selectors used by insertTag() to place the live <script>; without one the injector has no insertion point. Both may be strings (insertBefore wins), but neither being a string is fatal.

Source

Thrown at plugin/skills/impeccable/scripts/live-inject.mjs:466

function validateConfig(cfg) {
  if (!cfg || typeof cfg !== 'object') throw new Error('config.json must be an object');
  if (!Array.isArray(cfg.files) || cfg.files.length === 0) {
    throw new Error('config.files (non-empty string array) required');
  }
  if (!cfg.files.every((f) => typeof f === 'string' && f.length > 0)) {
    throw new Error('config.files must contain only non-empty strings');
  }
  if (cfg.exclude !== undefined) {
    if (!Array.isArray(cfg.exclude)) {
      throw new Error('config.exclude, if present, must be a string array');
    }
    if (!cfg.exclude.every((f) => typeof f === 'string' && f.length > 0)) {
      throw new Error('config.exclude must contain only non-empty strings');
    }
  }
  if (typeof cfg.insertBefore !== 'string' && typeof cfg.insertAfter !== 'string') {
    throw new Error('config.insertBefore or config.insertAfter (string) required');
  }
  if (cfg.commentSyntax !== 'html' && cfg.commentSyntax !== 'jsx') {
    throw new Error("config.commentSyntax must be 'html' or 'jsx'");
  }
  if (cfg.cspChecked !== undefined && typeof cfg.cspChecked !== 'boolean') {
    throw new Error("config.cspChecked, if present, must be a boolean");
  }
}

// ---------------------------------------------------------------------------
// Auto-execute
// ---------------------------------------------------------------------------

const _running = process.argv[1];
if (_running?.endsWith('live-inject.mjs') || _running?.endsWith('live-inject.mjs/')) {
  enterLiveRoot();
  injectCli();
}

View on GitHub (pinned to d14711ae3d)

Solutions

Set insertBefore to a string marker that exists in your HTML (e.g. '</head>' or '</body>') or insertAfter to an opening tag (e.g. '<body>').
Re-run live setup so the wizard detects the anchor from your entry-point file.
If using a framework adapter (Nuxt etc.) the adapter supplies its own insertion logic, but validateConfig still requires one of the two keys as a string.
Validate with `node live-inject.mjs --check`.

Example fix

// before
{ "files": ["index.html"], "commentSyntax": "html" }

// after
{ "files": ["index.html"], "commentSyntax": "html", "insertBefore": "</head>" }

Defensive patterns

Strategy: validation

Validate before calling

function hasInsertAnchor(cfg) {
  return typeof cfg?.insertBefore === 'string' || typeof cfg?.insertAfter === 'string';
}
if (!hasInsertAnchor(cfg)) {
  throw new Error('Provide config.insertBefore or config.insertAfter as a string anchor.');
}

Type guard

/** True when at least one anchor is a string. */
function hasAnchor(cfg) {
  return typeof cfg?.insertBefore === 'string' || typeof cfg?.insertAfter === 'string';
}

Try / catch

try {
  validateConfig(cfg);
} catch (err) {
  if (/insertBefore or config\.insertAfter/.test(err.message)) {
    cfg.insertBefore = '</head>';
    validateConfig(cfg);
  }
  throw err;
}

Prevention

Always set insertBefore (e.g. '</head>') or insertAfter (e.g. '<body>') as a string anchor.
Re-run live setup so the wizard detects an anchor from your entry-point file.
Even with a framework adapter, keep one anchor string to satisfy validation.

When it happens

Trigger: Both keys absent; both null; one present but as a non-string (e.g. a regex or array); only commentSyntax and files provided. The injector needs a literal string like '</head>' or '<body>' to locate the tag insertion point.

Common situations: Setup wizard didn't detect an anchor and left both blank; user removed the anchor keys thinking the injector would default; config copied from a project whose anchors differed; value accidentally set to a number or object.

Related errors

AI-assisted analysis of pbakaus/impeccable@d14711ae3d (2026-08-13). Data as JSON: /api/errors/5fa5d2702edc0330. Report an issue: GitHub.