Added segment parser logic

refs https://github.com/TryGhost/Team/issues/828

- This is experimental segment extraction logic, more to follow. Alllows to extract arrays of email segments used in the email's HTML content

core/server/services/mega/segment-parser.js

@@ -0,0 +1,13 @@
+const cheerio = require('cheerio');
+
+const getSegmentsFromHtml = (html) => {
+    const $ = cheerio.load(html);
+
+    const allSegments = $('[data-gh-segment]')
+        .get()
+        .map(el => el.attribs['data-gh-segment']);
+
+    return allSegments;
+};
+
+module.exports.getSegmentsFromHtml = getSegmentsFromHtml;

test/unit/services/mega/segment-parser_spec.js

@@ -0,0 +1,37 @@
+const should = require('should');
+
+const {getSegmentsFromHtml} = require('../../../../core/server/services/mega/segment-parser');
+
+describe('MEGA: Segment Parser', function () {
+    it('extracts a single segments used in HTML', function () {
+        const html = '<div data-gh-segment="status:-free"><p>Plain html with no replacements</p></div>';
+
+        const segments = getSegmentsFromHtml(html);
+
+        segments.length.should.equal(1);
+        segments[0].should.equal('status:-free');
+    });
+
+    it('extracts multiple segments used in HTML', function () {
+        const html = `
+            <div data-gh-segment="status:-free"><p>Text for paid</p></div>
+            <div data-gh-segment="status:free"><p>Text for free</p></div>
+            <div data-gh-segment="status:-free,label.slug:VIP"><p>Text for paid VIP</p></div>
+        `;
+
+        const segments = getSegmentsFromHtml(html);
+
+        segments.length.should.equal(3);
+        segments[0].should.equal('status:-free');
+        segments[1].should.equal('status:free');
+        segments[2].should.equal('status:-free,label.slug:VIP');
+    });
+
+    it('extracts no segments from HTML', function () {
+        const html = '<div data-gh-somethingelse="status:-free"><p>Plain html with no replacements</p></div>';
+
+        const segments = getSegmentsFromHtml(html);
+
+        segments.length.should.equal(0);
+    });
+});