Support subscription payment through Google Play Store (#8437)

* Support subscription payment through Google Play Store

* minor fixes to iap subscriptions

* Support subscription payment through Google Play Store

* minor fixes to iap subscriptions

* revert change to test

* add unit tests for google payments

* add integration tests for google payments

* change config formatting for play api

* fix typo in file name

* fix typo in example config

* Improve google payment tests

* fix linter errors

test/api/v3/integration/payments/google/POST-payments_google_verifyiap.js

@@ -0,0 +1,40 @@
+import {generateUser} from '../../../../../helpers/api-integration/v3';
+import googlePayments from '../../../../../../website/server/libs/googlePayments';
+
+describe('payments : google #verify', () => {
+  let endpoint = '/iap/android/verify';
+  let user;
+
+  beforeEach(async () => {
+    user = await generateUser();
+  });
+
+  describe('success', () => {
+    let verifyStub;
+
+    beforeEach(async () => {
+      verifyStub = sinon.stub(googlePayments, 'verifyGemPurchase').returnsPromise().resolves({});
+    });
+
+    afterEach(() => {
+      googlePayments.verifyGemPurchase.restore();
+    });
+
+    it('makes a purchase', async () => {
+      user = await generateUser({
+        balance: 2,
+      });
+
+      await user.post(endpoint, {
+        transaction: {receipt: 'receipt', signature: 'signature'},
+      });
+
+      expect(verifyStub).to.be.calledOnce;
+      expect(verifyStub.args[0][0]._id).to.eql(user._id);
+      expect(verifyStub.args[0][1]).to.eql('receipt');
+      expect(verifyStub.args[0][2]).to.eql('signature');
+      expect(verifyStub.args[0][3]['x-api-key']).to.eql(user.apiToken);
+      expect(verifyStub.args[0][3]['x-api-user']).to.eql(user._id);
+    });
+  });
+});