feat(v2): pluginify pages (#1278)

* feat(v2): convert pages into a plugin

* fix: update tests

v2/plugins/docusaurus-plugin-content-blog.js

@@ -1,142 +0,0 @@
-/**
- * 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 globby = require('globby');
-const path = require('path');
-const fs = require('fs-extra');
-// TODO: Do not make it relative because plugins can be from node_modules.
-const {parse, idx, normalizeUrl} = require('../lib/load/utils');
-
-function fileToUrl(fileName) {
-  return fileName
-    .replace('-', '/')
-    .replace('-', '/')
-    .replace('-', '/')
-    .replace(/\.md$/, '');
-}
-
-const DEFAULT_OPTIONS = {
-  metadataKey: 'blogMetadata',
-  metadataFileName: 'blogMetadata.json',
-  path: 'blog', // Path to data on filesystem.
-  routeBasePath: 'blog', // URL Route.
-  include: ['*.md, *.mdx'], // Extensions to include.
-  pageCount: 10, // How many entries per page.
-  blogPageComponent: '@theme/BlogPage',
-  blogPostComponent: '@theme/BlogPost',
-};
-
-class DocusaurusPluginContentBlog {
-  constructor(opts, context) {
-    this.options = {...DEFAULT_OPTIONS, ...opts};
-    this.context = context;
-    this.contentPath = path.resolve(this.context.siteDir, this.options.path);
-  }
-
-  getName() {
-    return 'docusaurus-plugin-content-blog';
-  }
-
-  // Fetches blog contents and returns metadata for the contents.
-  async loadContents() {
-    const {pageCount, include, routeBasePath} = this.options;
-    const {env, siteConfig} = this.context;
-    const blogDir = this.contentPath;
-
-    const {baseUrl} = siteConfig;
-    const blogFiles = await globby(include, {
-      cwd: blogDir,
-    });
-
-    // Prepare metadata container.
-    const blogMetadata = [];
-
-    // Language for each blog page.
-    const defaultLangTag = idx(env, ['translation', 'defaultLanguage', 'tag']);
-
-    await Promise.all(
-      blogFiles.map(async relativeSource => {
-        const source = path.join(blogDir, relativeSource);
-
-        const blogFileName = path.basename(relativeSource);
-        // Extract, YYYY, MM, DD from the file name.
-        const filePathDateArr = blogFileName.split('-');
-        const date = new Date(
-          `${filePathDateArr[0]}-${filePathDateArr[1]}-${
-            filePathDateArr[2]
-          }T06:00:00.000Z`,
-        );
-
-        const fileString = await fs.readFile(source, 'utf-8');
-        const {metadata: rawMetadata} = parse(fileString);
-        const metadata = {
-          permalink: normalizeUrl([
-            baseUrl,
-            routeBasePath,
-            fileToUrl(blogFileName),
-          ]),
-          source,
-          ...rawMetadata,
-          date,
-          language: defaultLangTag,
-        };
-        blogMetadata.push(metadata);
-      }),
-    );
-    blogMetadata.sort((a, b) => a.date - b.date);
-
-    // Blog page handling. Example: `/blog`, `/blog/page1`, `/blog/page2`
-    const numOfBlog = blogMetadata.length;
-    const numberOfPage = Math.ceil(numOfBlog / pageCount);
-    const basePageUrl = path.join(baseUrl, routeBasePath);
-
-    // eslint-disable-next-line
-    for (let page = 0; page < numberOfPage; page++) {
-      blogMetadata.push({
-        permalink: normalizeUrl([
-          basePageUrl,
-          `${page > 0 ? `page${page + 1}` : ''}`,
-        ]),
-        language: defaultLangTag,
-        isBlogPage: true,
-        posts: blogMetadata.slice(page * pageCount, (page + 1) * pageCount),
-      });
-    }
-
-    return blogMetadata;
-  }
-
-  async generateRoutes({metadata, actions}) {
-    const {blogPageComponent, blogPostComponent} = this.options;
-    const {addRoute} = actions;
-    metadata.forEach(metadataItem => {
-      const {isBlogPage, permalink} = metadataItem;
-      if (isBlogPage) {
-        addRoute({
-          path: permalink,
-          component: blogPageComponent,
-          metadata: metadataItem,
-          modules: metadataItem.posts.map(post => post.source),
-        });
-        return;
-      }
-
-      addRoute({
-        path: permalink,
-        component: blogPostComponent,
-        metadata: metadataItem,
-        modules: [metadataItem.source],
-      });
-    });
-  }
-
-  getPathsToWatch() {
-    return [this.contentPath];
-  }
-}
-
-module.exports = DocusaurusPluginContentBlog;