Groups can prevent members from getting gems (#8870)

* add possibility for group to block members from getting gems

* fixes

* fix tests

* adds some tests

* unit tests

* finish unit tests

* remove old code

test/api/v3/unit/libs/stripePayments.test.js

@@ -75,8 +75,29 @@ describe('Stripe Payments', () => {
       });
     });
 
+
+    it('should error if user cannot get gems', async () => {
+      gift = undefined;
+      sinon.stub(user, 'canGetGems').returnsPromise().resolves(false);
+
+      await expect(stripePayments.checkout({
+        token,
+        user,
+        gift,
+        groupId,
+        email,
+        headers,
+        coupon,
+      }, stripe)).to.eventually.be.rejected.and.to.eql({
+        httpCode: 401,
+        message: i18n.t('groupPolicyCannotGetGems'),
+        name: 'NotAuthorized',
+      });
+    });
+
     it('should purchase gems', async () => {
       gift = undefined;
+      sinon.stub(user, 'canGetGems').returnsPromise().resolves(true);
 
       await stripePayments.checkout({
         token,
@@ -102,16 +123,18 @@ describe('Stripe Payments', () => {
         paymentMethod: 'Stripe',
         gift,
       });
+      expect(user.canGetGems).to.be.calledOnce;
+      user.canGetGems.restore();
     });
 
     it('should gift gems', async () => {
       let receivingUser = new User();
-      receivingUser.save();
+      await receivingUser.save();
       gift = {
         type: 'gems',
+        uuid: receivingUser._id,
         gems: {
           amount: 16,
-          uuid: receivingUser._id,
         },
       };
 
@@ -125,7 +148,6 @@ describe('Stripe Payments', () => {
         coupon,
       }, stripe);
 
-      gift.member = receivingUser;
       expect(stripeChargeStub).to.be.calledOnce;
       expect(stripeChargeStub).to.be.calledWith({
         amount: '400',