Extract blog post truncation logic and add tests (#640)

lib/__tests__/build-files.test.js

@@ -0,0 +1,117 @@
+/**
+ * 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 cssnano = require('cssnano');
+const filepath = require('filepath');
+const fm = require('front-matter');
+const fs = require('fs-extra');
+const glob = require('glob-promise');
+const rimraf = require('rimraf');
+const shell = require('shelljs');
+
+const CWD = process.cwd();
+
+const siteConfig = require(CWD + '/website/siteConfig.js');
+const buildDir = CWD + '/website/build';
+const docsDir = CWD + '/docs';
+const staticCSSDir = CWD + '/website/static/css';
+
+let inputMarkdownFiles = [];
+let inputAssetsFiles = [];
+let outputHTMLFiles = [];
+let outputAssetsFiles = [];
+
+function generateSite() {
+  shell.cd('website');
+  shell.exec('yarn build');
+}
+
+function clearBuildFolder() {
+  return rimraf(buildDir);
+}
+
+beforeEach(() => {
+  shell.cd(CWD);
+});
+
+beforeAll(() => {
+  generateSite();
+  return Promise.all([
+    glob(docsDir + '/**/*.md'),
+    glob(buildDir + '/' + siteConfig.projectName + '/docs/*.html'),
+    glob(docsDir + '/assets/*'),
+    glob(buildDir + '/' + siteConfig.projectName + '/img/*'),
+  ]).then(function(results) {
+    [
+      inputMarkdownFiles,
+      outputHTMLFiles,
+      inputAssetsFiles,
+      outputAssetsFiles,
+    ] = results;
+    return;
+  });
+});
+
+function afterAll() {
+  clearBuildFolder();
+}
+
+test('Build folder exists', function() {
+  return fs.stat(buildDir).then(function(status) {
+    expect(status.isDirectory()).toBeTruthy();
+  });
+});
+
+test('Generated HTML for each Markdown resource', function() {
+  let metadata = [];
+  outputHTMLFiles.forEach(function(file) {
+    const path = filepath.create(file);
+    metadata.push(path.basename());
+  });
+  inputMarkdownFiles.forEach(function(file) {
+    const path = filepath.create(file);
+    const data = fs.readFileSync(file, 'utf8');
+    const frontmatter = fm(data);
+    expect(metadata).toContain(frontmatter.attributes.id + '.html');
+  });
+});
+
+test('Generated table of contents', function() {
+  outputHTMLFiles.forEach(function(file) {
+    const fileContents = fs.readFileSync(file, 'utf8');
+    expect(fileContents).not.toContain('<AUTOGENERATED_TABLE_OF_CONTENTS>');
+  });
+});
+
+test('Concatenated CSS files', function() {
+  return Promise.all([
+    glob(staticCSSDir + '/*.css'),
+    fs.readFile(
+      buildDir + '/' + siteConfig.projectName + '/css/main.css',
+      'utf8'
+    ),
+  ]).then(function(results) {
+    const [inputFiles, outputFile] = results;
+    inputFiles.forEach(async function(file) {
+      const contents = fs.readFileSync(file, 'utf8');
+      const {css} = await cssnano.process(contents, {}, {preset: 'default'});
+      expect(outputFile).toContain(css);
+    });
+  });
+});
+
+test('Copied assets from /docs/assets', function() {
+  let metadata = [];
+  outputAssetsFiles.forEach(function(file) {
+    const path = filepath.create(file);
+    metadata.push(path.basename());
+  });
+  inputAssetsFiles.forEach(function(file) {
+    const path = filepath.create(file);
+    expect(metadata).toContain(path.basename());
+  });
+});