added twitter embed tests

refs TryGhost/Team#2663
-added basic coverage for twitter embeds

ghost/core/test/unit/server/services/oembed/twitter-embed.test.js

@@ -0,0 +1,96 @@
+const assert = require('assert');
+const TwitterOEmbedProvider = require('../../../../../core/server/services/oembed/twitter-embed');
+const externalRequest = require('../../../../../core/server/lib/request-external');
+const nock = require('nock');
+const sinon = require('sinon');
+const dnsPromises = require('dns').promises;
+
+describe('TwitterOEmbedProvider', function () {
+    before(async function () {
+        nock.disableNetConnect();
+    });
+
+    beforeEach(function () {
+        // external requests will attempt dns lookup
+        sinon.stub(dnsPromises, 'lookup').callsFake(function () {
+            return Promise.resolve({address: '123.123.123.123'});
+        });
+    });
+
+    afterEach(async function () {
+        nock.cleanAll();
+        sinon.restore();
+    });
+
+    after(async function () {
+        nock.enableNetConnect();
+    });
+
+    it('Can support requests for Tweet URLs', async function () {
+        const provider = new TwitterOEmbedProvider();
+
+        const tweetURL = new URL(
+            'https://twitter.com/Ghost/status/1630581157568839683'
+        );
+
+        const supportsRequest = await provider.canSupportRequest(tweetURL);
+
+        assert(supportsRequest, 'Should support Tweet URL');
+    });
+
+    it('Receives JSON from external request to Twitter API', async function () {
+        const provider = new TwitterOEmbedProvider({
+            config: {
+                bearerToken: 'test'
+            }
+        });
+        const tweetURL = new URL(
+            'https://twitter.com/Ghost/status/1630581157568839683'
+        );
+    
+        // not certain why we hit publish.twitter.com 
+        nock('https://publish.twitter.com')
+            .get('/oembed')
+            .query(true)
+            .reply(200, {
+                data: {
+                    conversation_id: '1630581157568839683',
+                    public_metrics: {
+                        retweet_count: 6,
+                        reply_count: 1,
+                        like_count: 27
+                    }
+                },
+                includes: {
+                    verified: false,
+                    description: 'some description',
+                    location: 'someplace, somewhere'
+                }
+            });
+
+        nock('https://api.twitter.com')
+            .get('/2/tweets/')
+            .query(true)
+            .reply(200, {
+                data: {
+                    conversation_id: '1630581157568839683',
+                    public_metrics: {
+                        retweet_count: 6,
+                        reply_count: 1,
+                        like_count: 27
+                    }
+                },
+                includes: {
+                    verified: false,
+                    description: 'some description',
+                    location: 'someplace, somewhere'
+                }
+            });
+
+        const oembedData = await provider.getOEmbedData(tweetURL, externalRequest);
+
+        assert.equal(oembedData.type, 'twitter');
+        assert.ok(oembedData.data);
+        assert.ok(oembedData.includes);
+    });
+});