chore(core): refactor SEO into testable module

src/website/seo.js

@@ -0,0 +1,47 @@
+const fs = require('fs')
+const path = require('path')
+
+class SEO {
+  constructor (output, seoLocation, rootAlbum) {
+    this.output = output
+    this.seoPrefix = seoLocation + (seoLocation.endsWith('/') ? '' : '/')
+    this.album = rootAlbum
+  }
+
+  robots () {
+    return `User-Agent: *\nDisallow:\nSitemap: ${this.seoPrefix}sitemap.xml\n`
+  }
+
+  sitemap () {
+    const now = new Date().toISOString()
+    const prefix = this.seoPrefix
+    // gather all album pages
+    const urls = []
+    addAlbumUrls(urls, this.album)
+    // create one <url> section per album
+    const xml = urls.map(url => `
+  <url>
+    <loc>${prefix}${url}</loc>
+    <lastmod>${now}</lastmod>
+  </url>`)
+    // return the full document
+    return `<?xml version="1.0" encoding="UTF-8"?>
+<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">${xml.join('')}
+</urlset>
+`
+  }
+
+  writeFiles () {
+    const robotsFile = path.join(this.output, 'robots.txt')
+    const sitemapFile = path.join(this.output, 'sitemap.xml')
+    fs.writeFileSync(robotsFile, this.robots())
+    fs.writeFileSync(sitemapFile, this.sitemap())
+  }
+}
+
+function addAlbumUrls (list, album) {
+  list.push(album.url)
+  album.albums.forEach(subAlbum => addAlbumUrls(list, subAlbum))
+}
+
+module.exports = SEO

src/website/website.js

@@ -3,6 +3,7 @@ const path = require('path')
 const async = require('async')
 const resolvePkg = require('resolve-pkg')
 const Theme = require('./theme')
+const SEO = require('./seo')
 const pages = require('./pages')
 
 exports.build = function (rootAlbum, opts, callback) {
@@ -36,7 +37,11 @@ exports.build = function (rootAlbum, opts, callback) {
     next => async.series(tasks, next)
   ], callback)
 
-  outputSEO(opts.output, opts.seoLocation, rootAlbum)
+  // add robots & sitemap if needed
+  if (opts.seoLocation) {
+    const seo = new SEO(opts.output, opts.seoLocation, rootAlbum)
+    seo.writeFiles()
+  }
 }
 
 function localThemePath (themeName) {
@@ -58,37 +63,3 @@ function readThemeSettings (filepath) {
     throw new Error('Failed to parse JSON theme settings file: ' + filepath)
   }
 }
-
-function outputSEO (output, seoLocation, rootAlbum) {
-  // SEO (sitemap and robots.txt)
-  if (!seoLocation) {
-    return
-  }
-
-  // Guaranteed to end with slash
-  const seoPrefix = seoLocation + (seoLocation.endsWith('/') ? '' : '/')
-
-  // Generate robots.txt
-  const robotsTxt = 'User-Agent: *\nDisallow:\n\nSitemap: ' + seoPrefix + 'sitemap.xml\n'
-  fs.writeFileSync(path.join(output, 'robots.txt'), robotsTxt)
-
-  // Generate sitemap
-  let sitemapXML = '<?xml version="1.0" encoding="UTF-8"?>\n' +
-    '<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">\n'
-  const now = new Date().toISOString()
-
-  function addToSitemap (album) {
-    sitemapXML +=
-      '    <url>\n' +
-      '        <loc>' + seoPrefix + album.url + '</loc>\n' +
-      '        <lastmod>' + now + '</lastmod>\n' +
-      '    </url>\n'
-
-    album.albums.forEach((subAlbum) => addToSitemap(subAlbum))
-  }
-
-  addToSitemap(rootAlbum)
-
-  sitemapXML += '</urlset>\n'
-  fs.writeFileSync(path.join(output, 'sitemap.xml'), sitemapXML)
-}

test/website/seo.spec.js

@@ -0,0 +1,53 @@
+const should = require('should/as-function')
+const SEO = require('../../src/website/seo')
+const Album = require('../../src/model/album')
+
+describe('SEO', function () {
+  it('normalises the SEO location path (no slash)', function () {
+    const location = 'https://example.com'
+    const seo = new SEO('output', location, new Album('test'))
+    should(seo.seoPrefix).eql('https://example.com/')
+  })
+
+  it('normalises the SEO location path (slash)', function () {
+    const location = 'https://example.com/'
+    const seo = new SEO('output', location, new Album('test'))
+    should(seo.seoPrefix).eql('https://example.com/')
+  })
+
+  describe('robots.txt', function () {
+    it('allows all user agents', function () {
+      const seo = new SEO('output', 'https://example.com', new Album('test'))
+      const robots = seo.robots()
+      should(robots.includes('User-Agent: *')).eql(true)
+    })
+
+    it('points to the Sitemap', function () {
+      const seo = new SEO('output', 'https://example.com', new Album('test'))
+      const robots = seo.robots()
+      should(robots.includes('Sitemap: https://example.com/sitemap.xml')).eql(true)
+    })
+  })
+
+  describe('sitemap.xml', function () {
+    it('includes the root album', function () {
+      const album = new Album('test')
+      album.finalize()
+      const seo = new SEO('output', 'https://example.com', album)
+      const sitemap = seo.sitemap()
+      should(sitemap.includes('<loc>https://example.com/index.html</loc>')).eql(true)
+    })
+
+    it('includes nested albums', function () {
+      const album = new Album({
+        albums: [new Album('a'), new Album('b')]
+      })
+      album.finalize()
+      const seo = new SEO('output', 'https://example.com', album)
+      const sitemap = seo.sitemap()
+      should(sitemap.includes('<loc>https://example.com/index.html</loc>')).eql(true)
+      should(sitemap.includes('<loc>https://example.com/a.html</loc>')).eql(true)
+      should(sitemap.includes('<loc>https://example.com/b.html</loc>')).eql(true)
+    })
+  })
+})