feat(v2): docs plugin initial work (#1327)

* feat(v2): pluginify docs

* feat(v2): implement docs plugin

* fix(v2): fix bugs in docs plugin for translation and versioning

packages/docusaurus-plugin-content-docs/src/metadata.js

@@ -0,0 +1,179 @@
+/**
+ * Copyright (c) 2017-present, Facebook, Inc.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+const fs = require('fs-extra');
+const path = require('path');
+const {getSubFolder, idx, parse, normalizeUrl} = require('@docusaurus/utils');
+
+function getLanguage(filepath, refDir, env) {
+  const translationEnabled = idx(env, ['translation', 'enabled']);
+
+  if (translationEnabled) {
+    const detectedLangTag = getSubFolder(filepath, refDir);
+    const enabledLanguages = idx(env, ['translation', 'enabledLanguages']);
+    const langTags =
+      (enabledLanguages && enabledLanguages.map(lang => lang.tag)) || [];
+    if (langTags.includes(detectedLangTag)) {
+      return detectedLangTag;
+    }
+
+    const defaultLanguage = idx(env, ['translation', 'defaultLanguage']);
+    if (defaultLanguage && defaultLanguage.tag) {
+      return defaultLanguage.tag;
+    }
+  }
+
+  return null;
+}
+
+function getVersion(filepath, refDir, env) {
+  const versioningEnabled = idx(env, ['versioning', 'enabled']);
+
+  if (versioningEnabled) {
+    const subFolder = getSubFolder(filepath, refDir);
+
+    if (subFolder) {
+      const detectedVersion = subFolder.replace(/^version-/, '');
+      const versions = idx(env, ['versioning', 'versions']) || [];
+      if (versions.includes(detectedVersion)) {
+        return detectedVersion;
+      }
+    }
+
+    return 'next';
+  }
+
+  return null;
+}
+
+module.exports = async function processMetadata(
+  source,
+  refDir,
+  env,
+  order,
+  siteConfig,
+  docsBasePath,
+) {
+  const filepath = path.resolve(refDir, source);
+  const fileString = await fs.readFile(filepath, 'utf-8');
+  const {metadata} = parse(fileString);
+
+  // Default id is the file name.
+  if (!metadata.id) {
+    metadata.id = path.basename(source, path.extname(source));
+  }
+  if (metadata.id.includes('/')) {
+    throw new Error('Document id cannot include "/".');
+  }
+
+  // Default title is the id.
+  if (!metadata.title) {
+    metadata.title = metadata.id;
+  }
+
+  // Language.
+  const language = getLanguage(filepath, refDir, env);
+  metadata.language = language;
+  const langPart = (language && `${language}/`) || '';
+
+  // Version.
+  const defaultLangTag = idx(env, ['translation', 'defaultLanguage', 'tag']);
+  let versionRefDir = refDir;
+  if (language && language !== defaultLangTag) {
+    versionRefDir = path.join(refDir, language);
+  }
+  const version = getVersion(filepath, versionRefDir, env);
+  metadata.version = version;
+  const latestVersion = idx(env, ['versioning', 'latestVersion']);
+  const versionPart =
+    (version && version !== latestVersion && `${version}/`) || '';
+
+  // Convert temporarily metadata.id to the form of dirname/id without version/lang prefix.
+  // e.g.: file `versioned_docs/version-1.0.0/en/foo/bar.md` with id `version-1.0.0-bar` => `foo/bar`
+  if (language) {
+    metadata.id = metadata.id.replace(new RegExp(`^${language}-`), '');
+  }
+
+  if (version) {
+    metadata.id = metadata.id.replace(new RegExp(`^version-${version}-`), '');
+  }
+
+  const dirName = path.dirname(source);
+  if (dirName !== '.') {
+    let prefix = dirName;
+    if (language) {
+      prefix = prefix.replace(new RegExp(`^${language}`), '');
+    }
+    prefix = prefix.replace(/^\//, '');
+    if (version) {
+      prefix = prefix.replace(new RegExp(`^version-${version}`), '');
+    }
+    prefix = prefix.replace(/^\//, '');
+    if (prefix) {
+      metadata.id = `${prefix}/${metadata.id}`;
+    }
+  }
+
+  // The docs absolute file source.
+  // e.g: `/end/docs/hello.md` or `/end/website/versioned_docs/version-1.0.0/hello.md`
+  metadata.source = path.join(refDir, source);
+
+  // Build the permalink.
+  const {baseUrl} = siteConfig;
+
+  // If user has own custom permalink defined in frontmatter
+  // e.g: :baseUrl:docsUrl/:langPart/:versionPart/endiliey/:id
+  if (metadata.permalink) {
+    metadata.permalink = path.resolve(
+      metadata.permalink
+        .replace(/:baseUrl/, baseUrl)
+        .replace(/:docsUrl/, docsBasePath)
+        .replace(/:langPart/, langPart)
+        .replace(/:versionPart/, versionPart)
+        .replace(/:id/, metadata.id),
+    );
+  } else {
+    metadata.permalink = normalizeUrl([
+      baseUrl,
+      docsBasePath,
+      langPart,
+      versionPart,
+      metadata.id,
+    ]);
+  }
+
+  // If version.
+  if (version && version !== 'next') {
+    metadata.id = `version-${version}-${metadata.id}`;
+  }
+
+  // Save localized id before adding language on it.
+  metadata.localized_id = metadata.id;
+
+  // If language.
+  if (language) {
+    metadata.id = `${language}-${metadata.id}`;
+  }
+
+  // Determine order.
+  const id = metadata.localized_id;
+  if (order[id]) {
+    metadata.sidebar = order[id].sidebar;
+    metadata.category = order[id].category;
+    metadata.subCategory = order[id].subCategory;
+    if (order[id].next) {
+      metadata.next_id = order[id].next;
+      metadata.next = (language ? `${language}-` : '') + order[id].next;
+    }
+    if (order[id].previous) {
+      metadata.previous_id = order[id].previous;
+      metadata.previous = (language ? `${language}-` : '') + order[id].previous;
+    }
+  }
+
+  return metadata;
+};

packages/docusaurus-plugin-content-docs/src/order.js

@@ -0,0 +1,72 @@
+/**
+ * Copyright (c) 2017-present, Facebook, Inc.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+// Build the docs meta such as next, previous, category and sidebar.
+module.exports = function createOrder(allSidebars = {}) {
+  const order = {};
+
+  Object.keys(allSidebars).forEach(sidebarId => {
+    const sidebar = allSidebars[sidebarId];
+
+    const ids = [];
+    const categoryOrder = [];
+    const subCategoryOrder = [];
+    const indexItems = ({items, categoryLabel, subCategoryLabel}) => {
+      items.forEach(item => {
+        switch (item.type) {
+          case 'category':
+            indexItems({
+              items: item.items,
+              categoryLabel: categoryLabel || item.label,
+              subCategoryLabel: categoryLabel && item.label,
+            });
+            break;
+          case 'ref':
+          case 'link':
+            // Refs and links should not be shown in navigation.
+            break;
+          case 'doc':
+            ids.push(item.id);
+            categoryOrder.push(categoryLabel);
+            subCategoryOrder.push(subCategoryLabel);
+            break;
+          default:
+            throw new Error(
+              `Unknown item type: ${item.type}. Item: ${JSON.stringify(item)}`,
+            );
+        }
+      });
+    };
+
+    indexItems({items: sidebar});
+
+    // eslint-disable-next-line
+    for (let i = 0; i < ids.length; i++) {
+      const id = ids[i];
+      let previous;
+      let next;
+
+      if (i > 0) {
+        previous = ids[i - 1];
+      }
+
+      if (i < ids.length - 1) {
+        next = ids[i + 1];
+      }
+
+      order[id] = {
+        previous,
+        next,
+        sidebar: sidebarId,
+        category: categoryOrder[i],
+        subCategory: subCategoryOrder[i],
+      };
+    }
+  });
+
+  return order;
+};

packages/docusaurus-plugin-content-docs/src/sidebars.js

@@ -0,0 +1,150 @@
+/**
+ * Copyright (c) 2017-present, Facebook, Inc.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+const fs = require('fs-extra');
+const path = require('path');
+const {idx} = require('@docusaurus/utils');
+
+/**
+ * Check that item contains only allowed keys
+ *
+ * @param {Object} item
+ * @param {Array<string>} keys
+ */
+function assertItem(item, keys) {
+  const unknownKeys = Object.keys(item).filter(
+    key => !keys.includes(key) && key !== 'type',
+  );
+
+  if (unknownKeys.length) {
+    throw new Error(
+      `Unknown sidebar item keys: ${unknownKeys}. Item: ${JSON.stringify(
+        item,
+      )}`,
+    );
+  }
+}
+
+/**
+ * Normalizes recursively category and all its children. Ensures, that at the end
+ * each item will be an object with the corresponding type
+ *
+ * @param {Array<Object>} category
+ * @param {number} [level=0]
+ *
+ * @return {Array<Object>}
+ */
+function normalizeCategory(category, level = 0) {
+  if (level === 2) {
+    throw new Error(
+      `Can not process ${
+        category.label
+      } category. Categories can be nested only one level deep.`,
+    );
+  }
+
+  assertItem(category, ['items', 'label']);
+
+  if (!Array.isArray(category.items)) {
+    throw new Error(
+      `Error loading ${category.label} category. Category items must be array.`,
+    );
+  }
+
+  const items = category.items.map(item => {
+    switch (item.type) {
+      case 'category':
+        return normalizeCategory(item, level + 1);
+      case 'link':
+        assertItem(item, ['href', 'label']);
+        break;
+      case 'ref':
+        assertItem(item, ['id', 'label']);
+        break;
+      default:
+        if (typeof item === 'string') {
+          return {
+            type: 'doc',
+            id: item,
+          };
+        }
+
+        if (item.type !== 'doc') {
+          throw new Error(`Unknown sidebar item type: ${item.type}`);
+        }
+
+        assertItem(item, ['id', 'label']);
+        break;
+    }
+
+    return item;
+  });
+
+  return {...category, items};
+}
+
+/**
+ * Converts sidebars object to mapping to arrays of sidebar item objects
+ *
+ * @param  {{[key: string]: Object}} sidebars
+ *
+ * @return {{[key: string]: Array<Object>}}
+ */
+function normalizeSidebar(sidebars) {
+  return Object.entries(sidebars).reduce((acc, [sidebarId, sidebar]) => {
+    let normalizedSidebar = sidebar;
+
+    if (!Array.isArray(sidebar)) {
+      // convert sidebar to a more generic structure
+      normalizedSidebar = Object.entries(sidebar).map(([label, items]) => ({
+        type: 'category',
+        label,
+        items,
+      }));
+    }
+
+    acc[sidebarId] = normalizedSidebar.map(item => normalizeCategory(item));
+
+    return acc;
+  }, {});
+}
+
+module.exports = function loadSidebars({siteDir, env}, deleteCache = true) {
+  let allSidebars = {};
+
+  // current sidebars
+  const sidebarsJSONFile = path.join(siteDir, 'sidebars.json');
+  if (deleteCache) {
+    delete require.cache[sidebarsJSONFile];
+  }
+  if (fs.existsSync(sidebarsJSONFile)) {
+    allSidebars = require(sidebarsJSONFile); // eslint-disable-line
+  }
+
+  // versioned sidebars
+  if (idx(env, ['versioning', 'enabled'])) {
+    const versions = idx(env, ['versioning', 'versions']);
+    if (Array.isArray(versions)) {
+      versions.forEach(version => {
+        const versionedSidebarsJSONFile = path.join(
+          siteDir,
+          'versioned_sidebars',
+          `version-${version}-sidebars.json`,
+        );
+        if (fs.existsSync(versionedSidebarsJSONFile)) {
+          const sidebar = require(versionedSidebarsJSONFile); // eslint-disable-line
+          Object.assign(allSidebars, sidebar);
+        } else {
+          const missingFile = path.relative(siteDir, versionedSidebarsJSONFile);
+          throw new Error(`Failed to load ${missingFile}. It does not exist.`);
+        }
+      });
+    }
+  }
+
+  return normalizeSidebar(allSidebars);
+};