feat: init @vuepress/plugin-blog

Author: ulivz

packages/@vuepress/plugin-blog/.npmignore

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+__tests__
+__mocks__

packages/@vuepress/plugin-blog/README.md

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+# @vuepress/plugin-blog
+
+> theme plugin for vuepress

packages/@vuepress/plugin-blog/index.js

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+module.exports = (options, ctx) => ({
+  extendPageData (pageCtx) {
+    const {
+      _frontmatterMeta     // result of parseFrontmatter
+      // type: { data: FrontMatterObject, content: rest content }
+
+      // _filePath,        // file's absolute path
+      // _content,         // file's raw content string
+      // key,              // file's hash key
+      // regularPath       // current page's default link (follow the file hierarchy)
+    } = pageCtx
+
+    const { data: rawFrontmatter } = _frontmatterMeta
+    const { layoutComponentMap } = ctx
+    const { pageEnhancers = [] } = options
+    const isLayoutExists = name => layoutComponentMap[name] !== undefined
+    const getLayout = name => isLayoutExists(name) ? name : 'Layout'
+
+    const enhancers = [
+      {
+        when: ({ regularPath }) => regularPath === '/category/',
+        frontmatter: { layout: getLayout('Category') }
+      },
+      {
+        when: ({ regularPath }) => regularPath === '/tags/',
+        frontmatter: { layout: getLayout('Tag') }
+      },
+      {
+        when: ({ regularPath }) => regularPath.startsWith('/_posts/'),
+        frontmatter: {
+          layout: getLayout('Post'),
+          permalink: '/:year/:month/:day/:slug'
+        }
+      },
+      ...pageEnhancers
+    ]
+
+    enhancers.forEach(({
+      when,
+      frontmatter = {}
+    }) => {
+      if (when(pageCtx)) {
+        Object.assign(rawFrontmatter, frontmatter)
+      }
+    })
+  }
+})

packages/@vuepress/plugin-blog/package.json

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+{
+  "name": "@vuepress/plugin-blog",
+  "version": "1.0.0",
+  "description": "theme plugin for vuepress",
+  "main": "index.js",
+  "publishConfig": {
+    "access": "public"
+  },
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/vuejs/vuepress.git"
+  },
+  "keywords": [
+    "documentation",
+    "vue",
+    "vuepress",
+    "generator"
+  ],
+  "author": "Evan You",
+  "license": "MIT",
+  "bugs": {
+    "url": "https://github.com/vuejs/vuepress/issues"
+  },
+  "homepage": "https://github.com/vuejs/vuepress/packages/@vuepress/plugin-blog#readme"
+}