Function parseAndBuildMetadata

packages/babel-template/src/parse.ts:37–71

(
  formatter: Formatter<T>,
  code: string,
  opts: TemplateOpts,
)

const PATTERN = /^[_$A-Z0-9]+$/;

export default function parseAndBuildMetadata<T>(
  formatter: Formatter<T>,
  code: string,
  opts: TemplateOpts,
): Metadata {
  const {
    placeholderAllowlist,
    placeholderPattern,
    preserveComments = false,
    syntacticPlaceholders,
  } = opts;

  const ast = parseWithCodeFrame(code, opts.parser, syntacticPlaceholders);

  removePropertiesDeep(ast, {
    preserveComments,
  });

  formatter.validate(ast);

  const state: MetadataState = {
    syntactic: { placeholders: [], placeholderNames: new Set() },
    legacy: { placeholders: [], placeholderNames: new Set() },
    placeholderAllowlist,
    placeholderPattern,
    syntacticPlaceholders,
  };

  traverse(ast, placeholderVisitorHandler, state);

  return {
    ast,
    ...(state.syntactic.placeholders.length ? state.syntactic : state.legacy),
  };
}

function placeholderVisitorHandler(
  node: t.Node,