refactor(content-docs): split version handling into several files (#7140)

* refactor(content-docs): split version handling into several files

* fix test

* increase timeout

packages/docusaurus-plugin-content-docs/src/versions/files.ts

@@ -0,0 +1,220 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import path from 'path';
+import fs from 'fs-extra';
+import {
+  VERSIONS_JSON_FILE,
+  VERSIONED_DOCS_DIR,
+  VERSIONED_SIDEBARS_DIR,
+  CURRENT_VERSION_NAME,
+} from '../constants';
+import {validateVersionNames} from './validation';
+import {getPluginI18nPath, DEFAULT_PLUGIN_ID} from '@docusaurus/utils';
+import type {
+  PluginOptions,
+  VersionMetadata,
+} from '@docusaurus/plugin-content-docs';
+import type {VersionContext} from './index';
+
+/** Add a prefix like `community_version-1.0.0`. No-op for default instance. */
+function addPluginIdPrefix(fileOrDir: string, pluginId: string): string {
+  return pluginId === DEFAULT_PLUGIN_ID
+    ? fileOrDir
+    : `${pluginId}_${fileOrDir}`;
+}
+
+/** `[siteDir]/community_versioned_docs/version-1.0.0` */
+export function getVersionDocsDirPath(
+  siteDir: string,
+  pluginId: string,
+  versionName: string,
+): string {
+  return path.join(
+    siteDir,
+    addPluginIdPrefix(VERSIONED_DOCS_DIR, pluginId),
+    `version-${versionName}`,
+  );
+}
+
+/** `[siteDir]/community_versioned_sidebars/version-1.0.0-sidebars.json` */
+export function getVersionSidebarsPath(
+  siteDir: string,
+  pluginId: string,
+  versionName: string,
+): string {
+  return path.join(
+    siteDir,
+    addPluginIdPrefix(VERSIONED_SIDEBARS_DIR, pluginId),
+    `version-${versionName}-sidebars.json`,
+  );
+}
+
+export function getDocsDirPathLocalized({
+  siteDir,
+  locale,
+  pluginId,
+  versionName,
+}: {
+  siteDir: string;
+  locale: string;
+  pluginId: string;
+  versionName: string;
+}): string {
+  return getPluginI18nPath({
+    siteDir,
+    locale,
+    pluginName: 'docusaurus-plugin-content-docs',
+    pluginId,
+    subPaths: [
+      versionName === CURRENT_VERSION_NAME
+        ? CURRENT_VERSION_NAME
+        : `version-${versionName}`,
+    ],
+  });
+}
+
+/** `community` => `[siteDir]/community_versions.json` */
+export function getVersionsFilePath(siteDir: string, pluginId: string): string {
+  return path.join(siteDir, addPluginIdPrefix(VERSIONS_JSON_FILE, pluginId));
+}
+
+/**
+ * Reads the plugin's respective `versions.json` file, and returns its content.
+ *
+ * @throws Throws if validation fails, i.e. `versions.json` doesn't contain an
+ * array of valid version names.
+ */
+async function readVersionsFile(
+  siteDir: string,
+  pluginId: string,
+): Promise<string[] | null> {
+  const versionsFilePath = getVersionsFilePath(siteDir, pluginId);
+  if (await fs.pathExists(versionsFilePath)) {
+    const content = await fs.readJSON(versionsFilePath);
+    validateVersionNames(content);
+    return content;
+  }
+  return null;
+}
+
+/**
+ * Reads the `versions.json` file, and returns an ordered list of version names.
+ *
+ * - If `disableVersioning` is turned on, it will return `["current"]` (requires
+ * `includeCurrentVersion` to be true);
+ * - If `includeCurrentVersion` is turned on, "current" will be inserted at the
+ * beginning, if not already there.
+ *
+ * You need to use {@link filterVersions} after this.
+ *
+ * @throws Throws an error if `disableVersioning: true` but `versions.json`
+ * doesn't exist (i.e. site is not versioned)
+ * @throws Throws an error if versions list is empty (empty `versions.json` or
+ * `disableVersioning` is true, and not including current version)
+ */
+export async function readVersionNames(
+  siteDir: string,
+  options: PluginOptions,
+): Promise<string[]> {
+  const versionFileContent = await readVersionsFile(siteDir, options.id);
+
+  if (!versionFileContent && options.disableVersioning) {
+    throw new Error(
+      `Docs: using "disableVersioning: true" option on a non-versioned site does not make sense.`,
+    );
+  }
+
+  const versions = options.disableVersioning ? [] : versionFileContent ?? [];
+
+  // We add the current version at the beginning, unless:
+  // - user don't want to; or
+  // - it's already been explicitly added to versions.json
+  if (
+    options.includeCurrentVersion &&
+    !versions.includes(CURRENT_VERSION_NAME)
+  ) {
+    versions.unshift(CURRENT_VERSION_NAME);
+  }
+
+  if (versions.length === 0) {
+    throw new Error(
+      `It is not possible to use docs without any version. No version is included because you have requested to not include ${path.resolve(
+        options.path,
+      )} through "includeCurrentVersion: false", while ${
+        options.disableVersioning
+          ? 'versioning is disabled with "disableVersioning: true"'
+          : `the versions file is empty/non-existent`
+      }.`,
+    );
+  }
+
+  return versions;
+}
+
+/**
+ * Gets the path-related version metadata.
+ *
+ * @throws Throws if the resolved docs folder or sidebars file doesn't exist.
+ * Does not throw if a versioned sidebar is missing (since we don't create empty
+ * files).
+ */
+export async function getVersionMetadataPaths({
+  versionName,
+  context,
+  options,
+}: VersionContext): Promise<
+  Pick<
+    VersionMetadata,
+    'contentPath' | 'contentPathLocalized' | 'sidebarFilePath'
+  >
+> {
+  const isCurrent = versionName === CURRENT_VERSION_NAME;
+  const contentPathLocalized = getDocsDirPathLocalized({
+    siteDir: context.siteDir,
+    locale: context.i18n.currentLocale,
+    pluginId: options.id,
+    versionName,
+  });
+  const contentPath = isCurrent
+    ? path.resolve(context.siteDir, options.path)
+    : getVersionDocsDirPath(context.siteDir, options.id, versionName);
+  const sidebarFilePath = isCurrent
+    ? options.sidebarPath
+    : getVersionSidebarsPath(context.siteDir, options.id, versionName);
+
+  if (!(await fs.pathExists(contentPath))) {
+    throw new Error(
+      `The docs folder does not exist for version "${versionName}". A docs folder is expected to be found at ${path.relative(
+        context.siteDir,
+        contentPath,
+      )}.`,
+    );
+  }
+
+  // If the current version defines a path to a sidebar file that does not
+  // exist, we throw! Note: for versioned sidebars, the file may not exist (as
+  // we prefer to not create it rather than to create an empty file)
+  // See https://github.com/facebook/docusaurus/issues/3366
+  // See https://github.com/facebook/docusaurus/pull/4775
+  if (
+    versionName === CURRENT_VERSION_NAME &&
+    typeof sidebarFilePath === 'string' &&
+    !(await fs.pathExists(sidebarFilePath))
+  ) {
+    throw new Error(`The path to the sidebar file does not exist at "${path.relative(
+      context.siteDir,
+      sidebarFilePath,
+    )}".
+Please set the docs "sidebarPath" field in your config file to:
+- a sidebars path that exists
+- false: to disable the sidebar
+- undefined: for Docusaurus to generate it automatically`);
+  }
+
+  return {contentPath, contentPathLocalized, sidebarFilePath};
+}