Refactored email utils to a class with DI params

refs https://github.com/TryGhost/Toolbox/issues/292

- There's a need to reuse these utils in the version mismatch notification service. Having loads of tightly coupled dependencies makes it super hard to rip out this module for reuse
- It's a groundwork for extraction of the email-utils package
- Rewrote the unit tests that were written for these utils previously - they weren't testing anything useful. The goal of this util is to generate specific content based on provided data and available templates - now the tests do test those specific things, not the mailer itself!

core/server/services/mail/EmailContentGenerator.js

@@ -0,0 +1,55 @@
+const _ = require('lodash').runInContext();
+const fs = require('fs-extra');
+const path = require('path');
+const htmlToText = require('html-to-text');
+
+_.templateSettings.interpolate = /{{([\s\S]+?)}}/g;
+
+class EmailContentGenerator {
+    /**
+     *
+     * @param {Object} options
+     * @param {function} options.getSiteUrl
+     * @param {function} options.getSiteTitle
+     * @param {string} options.templatesDir - path to the directory containing email templates
+     */
+    constructor({getSiteUrl, getSiteTitle, templatesDir}) {
+        this.getSiteUrl = getSiteUrl;
+        this.getSiteTitle = getSiteTitle;
+        this.templatesDir = templatesDir;
+    }
+
+    /**
+     *
+     * @param {Object} options
+     * @param {string} options.template - HTML template name to use for generation
+     * @param {Object} [options.data] - variable data to use during HTML template compilation
+     * @returns {Promise} resolves with an object containing html and text properties
+     */
+    async getContent(options) {
+        const defaults = {
+            siteUrl: this.getSiteUrl(),
+            siteTitle: this.getSiteTitle()
+        };
+
+        const data = _.defaults(defaults, options.data);
+
+        // read the proper email body template
+        return fs.readFile(path.join(this.templatesDir, options.template + '.html'), 'utf8')
+            .then(function (content) {
+                // insert user-specific data into the email
+                const compiled = _.template(content);
+                const htmlContent = compiled(data);
+
+                // generate a plain-text version of the same email
+                const textContent = htmlToText.fromString(htmlContent);
+
+                return {
+                    html: htmlContent,
+                    text: textContent
+                };
+            });
+    }
+}
+
+module.exports = EmailContentGenerator;

core/server/services/mail/index.js

@@ -1,2 +1,15 @@
+const path = require('path');
+const urlUtils = require('../../../shared/url-utils');
+const settingsCache = require('../../../shared/settings-cache');
+const EmailContentGenerator = require('./EmailContentGenerator');
+
+const emailContentGenerator = new EmailContentGenerator({
+    getSiteUrl: () => urlUtils.urlFor('home', true),
+    getSiteTitle: () => settingsCache.get('title'),
+    templatesDir: path.resolve(__dirname, '..', 'mail', 'templates')
+});
+
 exports.GhostMailer = require('./GhostMailer');
-exports.utils = require('./utils');
+exports.utils = {
+    generateContent: emailContentGenerator.getContent.bind(emailContentGenerator)
+};

core/server/services/mail/utils.js

@@ -1,34 +0,0 @@
-const _ = require('lodash').runInContext();
-const fs = require('fs-extra');
-const path = require('path');
-const htmlToText = require('html-to-text');
-const urlUtils = require('../../../shared/url-utils');
-const settingsCache = require('../../../shared/settings-cache');
-const templatesDir = path.resolve(__dirname, '..', 'mail', 'templates');
-
-_.templateSettings.interpolate = /{{([\s\S]+?)}}/g;
-
-exports.generateContent = function generateContent(options) {
-    const defaults = {
-        siteUrl: urlUtils.urlFor('home', true),
-        siteTitle: settingsCache.get('title')
-    };
-
-    const data = _.defaults(defaults, options.data);
-
-    // read the proper email body template
-    return fs.readFile(path.join(templatesDir, options.template + '.html'), 'utf8')
-        .then(function (content) {
-            // insert user-specific data into the email
-            const compiled = _.template(content);
-            const htmlContent = compiled(data);
-
-            // generate a plain-text version of the same email
-            const textContent = htmlToText.fromString(htmlContent);
-
-            return {
-                html: htmlContent,
-                text: textContent
-            };
-        });
-};

test/unit/server/services/mail/utils.test.js

@@ -1,41 +1,38 @@
-const should = require('should');
+const assert = require('assert');
-const sinon = require('sinon');
+const path = require('path');
-const mail = require('../../../../../core/server/services/mail');
-const configUtils = require('../../../../utils/configUtils');
 
-describe('Mail: Utils', function () {
+const EmailContentGenerator = require('../../../../../core/server/services/mail/EmailContentGenerator');
-    const scope = {ghostMailer: null};
 
-    beforeEach(function () {
+describe('Mail: EmailContentGenerator', function () {
-        configUtils.set({mail: {transport: 'stub'}});
+    it('generate welcome', async function () {
-        scope.ghostMailer = new mail.GhostMailer();
+        const emailContentGenerator = new EmailContentGenerator({
+            getSiteTitle: () => 'The Ghost Blog',
+            getSiteUrl: () => 'http://myblog.com',
+            templatesDir: path.resolve(__dirname, '../../../../../core/server/services/mail/templates/')
         });
 
-    afterEach(function () {
+        const content = await emailContentGenerator.getContent({
-        sinon.restore();
-        configUtils.restore();
-    });
-
-    it('generate welcome', function (done) {
-        mail.utils.generateContent({
             template: 'welcome',
             data: {
                 ownerEmail: 'test@example.com'
             }
-        }).then(function (result) {
-            return scope.ghostMailer.send({
-                to: 'test@example.com',
-                subject: 'lol',
-                html: result.html,
-                text: result.text
-            });
-        }).then(function () {
-            done();
-        }).catch(done);
         });
 
-    it('generates newsletter template', function (done) {
+        assert.match(content.html, /<title>Welcome to Ghost<\/title>/);
-        mail.utils.generateContent({
+        assert.match(content.html, /This email was sent from <a href="http:\/\/myblog.com" style="color: #738A94;">http:\/\/myblog.com<\/a> to <a href="mailto:test@example.com" style="color: #738A94;">test@example.com<\/a><\/p>/);
+
+        assert.match(content.text, /Email Address: test@example.com \[test@example.com\]/);
+        assert.match(content.text, /This email was sent from http:\/\/myblog.com/);
+    });
+
+    it('generates newsletter template', async function () {
+        const emailContentGenerator = new EmailContentGenerator({
+            getSiteTitle: () => 'The Ghost Blog',
+            getSiteUrl: () => 'http://myblog.com',
+            templatesDir: path.resolve(__dirname, '../../../../../core/server/services/mail/templates/')
+        });
+
+        const content = await emailContentGenerator.getContent({
             template: 'newsletter',
             data: {
                 blog: {
@@ -93,15 +90,13 @@ describe('Mail: Utils', function () {
                     date: 'june, 9th 2016'
                 }
             }
-        }).then(function (result) {
-            return scope.ghostMailer.send({
-                to: 'jbloggs@example.com',
-                subject: 'The Newsletter Blog',
-                html: result.html,
-                text: result.text
         });
-        }).then(function () {
+
-            done();
+        assert.match(content.html, /<title>The Ghost Blog<\/title>/);
-        }).catch(done);
+        assert.match(content.html, /<span style="text-transform:capitalize">monthly<\/span> digest/);
+        assert.match(content.html, /<span style="text-transform:capitalize">june, 9th 2016<\/span><\/h3>/);
+
+        assert.match(content.text, /MONTHLY DIGEST — JUNE, 9TH 2016/);
+        assert.match(content.text, /SECOND BLOG POST \[HTTP:\/\/MYBLOG.COM\/SECOND-BLOG-POST\]/);
     });
 });