feat(v2): generate sitemap (#1065)

* feat(v2): generate sitemap

* cannot snapshot sitemap because xml generated in different order

v2/lib/commands/build.js

@@ -4,6 +4,7 @@ const chalk = require('chalk');
 const fs = require('fs-extra');
 const globby = require('globby');
 const load = require('../load');
+const createSitemap = require('../core/sitemap');
 const createServerConfig = require('../webpack/server');
 const createClientConfig = require('../webpack/client');
 const {applyConfigureWebpack} = require('../webpack/utils');
@@ -67,6 +68,11 @@ module.exports = async function build(siteDir) {
     }),
   );
 
+  // generate sitemap
+  const sitemap = await createSitemap(props);
+  const sitemapPath = path.join(outDir, 'sitemap.xml');
+  await fs.writeFile(sitemapPath, sitemap);
+
   const relativeDir = path.relative(process.cwd(), outDir);
   console.log(
     `\n${chalk.green('Success!')} Generated static files in ${chalk.cyan(

v2/lib/core/sitemap.js

@@ -0,0 +1,38 @@
+const sitemap = require('sitemap');
+
+module.exports = async function createSitemap({
+  siteConfig = {},
+  docsMetadatas = {},
+  pagesMetadatas = [],
+  blogMetadatas = [],
+}) {
+  const allMetadatas = [
+    ...blogMetadatas,
+    ...Object.values(docsMetadatas),
+    ...pagesMetadatas,
+  ];
+
+  const {url: siteUrl} = siteConfig;
+
+  if (!siteUrl) {
+    throw new Error('Url in siteConfig.js cannot be empty/undefined');
+  }
+
+  const urls = [];
+
+  allMetadatas.forEach(metadata => {
+    urls.push({
+      url: metadata.permalink,
+      changefreq: 'weekly',
+      priority: 0.5,
+    });
+  });
+
+  const sm = sitemap.createSitemap({
+    hostname: siteUrl,
+    cacheTime: 600 * 1000, // 600 sec - cache purge period
+    urls,
+  });
+
+  return sm.toString();
+};

v2/lib/load/config.js

@@ -17,6 +17,7 @@ module.exports = function loadConfig(siteDir, deleteCache = true) {
     'organizationName',
     'projectName',
     'baseUrl',
+    'url',
   ];
   const optionalFields = [
     'customDocsPath',