function doProcessDocMetadata()

in packages/docusaurus-plugin-content-docs/src/docs.ts [113:264]

• 79 lines of code
• 6 McCabe index (conditional complexity)

function doProcessDocMetadata({
  docFile,
  versionMetadata,
  context,
  options,
}: {
  docFile: DocFile;
  versionMetadata: VersionMetadata;
  context: LoadContext;
  options: MetadataOptions;
}): DocMetadataBase {
  const {source, content, lastUpdate, contentPath, filePath} = docFile;
  const {siteDir, i18n} = context;

  const {
    frontMatter: unsafeFrontMatter,
    contentTitle,
    excerpt,
  } = parseMarkdownString(content);
  const frontMatter = validateDocFrontMatter(unsafeFrontMatter);

  const {
    custom_edit_url: customEditURL,

    // Strip number prefixes by default
    // (01-MyFolder/01-MyDoc.md => MyFolder/MyDoc)
    // but allow to disable this behavior with front matter
    parse_number_prefixes: parseNumberPrefixes = true,
  } = frontMatter;

  // ex: api/plugins/myDoc -> myDoc
  // ex: myDoc -> myDoc
  const sourceFileNameWithoutExtension = path.basename(
    source,
    path.extname(source),
  );

  // ex: api/plugins/myDoc -> api/plugins
  // ex: myDoc -> .
  const sourceDirName = path.dirname(source);

  const {filename: unprefixedFileName, numberPrefix} = parseNumberPrefixes
    ? options.numberPrefixParser(sourceFileNameWithoutExtension)
    : {filename: sourceFileNameWithoutExtension, numberPrefix: undefined};

  const baseID: string = frontMatter.id ?? unprefixedFileName;
  if (baseID.includes('/')) {
    throw new Error(`Document id "${baseID}" cannot include slash.`);
  }

  // For autogenerated sidebars, sidebar position can come from filename number
  // prefix or front matter
  const sidebarPosition: number | undefined =
    frontMatter.sidebar_position ?? numberPrefix;

  // TODO legacy retrocompatibility
  // The same doc in 2 distinct version could keep the same id,
  // we just need to namespace the data by version
  const versionIdPrefix =
    versionMetadata.versionName === CURRENT_VERSION_NAME
      ? undefined
      : `version-${versionMetadata.versionName}`;

  // TODO legacy retrocompatibility
  // I think it's bad to affect the front matter id with the dirname?
  function computeDirNameIdPrefix() {
    if (sourceDirName === '.') {
      return undefined;
    }
    // Eventually remove the number prefixes from intermediate directories
    return parseNumberPrefixes
      ? stripPathNumberPrefixes(sourceDirName, options.numberPrefixParser)
      : sourceDirName;
  }

  const unversionedId = [computeDirNameIdPrefix(), baseID]
    .filter(Boolean)
    .join('/');

  // TODO is versioning the id very useful in practice?
  // legacy versioned id, requires a breaking change to modify this
  const id = [versionIdPrefix, unversionedId].filter(Boolean).join('/');

  const docSlug = getSlug({
    baseID,
    source,
    sourceDirName,
    frontMatterSlug: frontMatter.slug,
    stripDirNumberPrefixes: parseNumberPrefixes,
    numberPrefixParser: options.numberPrefixParser,
  });

  // Note: the title is used by default for page title, sidebar label,
  // pagination buttons... frontMatter.title should be used in priority over
  // contentTitle (because it can contain markdown/JSX syntax)
  const title: string = frontMatter.title ?? contentTitle ?? baseID;

  const description: string = frontMatter.description ?? excerpt ?? '';

  const permalink = normalizeUrl([versionMetadata.path, docSlug]);

  function getDocEditUrl() {
    const relativeFilePath = path.relative(contentPath, filePath);

    if (typeof options.editUrl === 'function') {
      return options.editUrl({
        version: versionMetadata.versionName,
        versionDocsDirPath: posixPath(
          path.relative(siteDir, versionMetadata.contentPath),
        ),
        docPath: posixPath(relativeFilePath),
        permalink,
        locale: context.i18n.currentLocale,
      });
    } else if (typeof options.editUrl === 'string') {
      const isLocalized = contentPath === versionMetadata.contentPathLocalized;
      const baseVersionEditUrl =
        isLocalized && options.editLocalizedFiles
          ? versionMetadata.editUrlLocalized
          : versionMetadata.editUrl;
      return getEditUrl(relativeFilePath, baseVersionEditUrl);
    }
    return undefined;
  }

  // Assign all of object properties during instantiation (if possible) for
  // NodeJS optimization.
  // Adding properties to object after instantiation will cause hidden
  // class transitions.
  return {
    unversionedId,
    id,
    title,
    description,
    source: aliasedSitePath(filePath, siteDir),
    sourceDirName,
    slug: docSlug,
    permalink,
    editUrl: customEditURL !== undefined ? customEditURL : getDocEditUrl(),
    tags: normalizeFrontMatterTags(versionMetadata.tagsPath, frontMatter.tags),
    version: versionMetadata.versionName,
    lastUpdatedBy: lastUpdate.lastUpdatedBy,
    lastUpdatedAt: lastUpdate.lastUpdatedAt,
    formattedLastUpdatedAt: lastUpdate.lastUpdatedAt
      ? new Intl.DateTimeFormat(i18n.currentLocale).format(
          lastUpdate.lastUpdatedAt * 1000,
        )
      : undefined,
    sidebarPosition,
    frontMatter,
  };
}