Allow group plans for private guilds only (#12479)

* hide upgrade button for public guilds

* prevent group plans for public guilds

* fix unit tests

* fix integration and unit tests that assumed group plans could be public guilds

* more unit tests fixes

* more resilient unit test

* more resilient unit test

test/api/v3/integration/groups/POST-groups_groupId_leave.test.js

@@ -274,6 +274,7 @@ describe('POST /groups/:groupId/leave', () => {
 
   each(typesOfGroups, (groupDetails, groupType) => {
     context(`Leaving a group plan when the group is a ${groupType}`, () => {
+      if (groupDetails.privacy === 'public') return; // public guilds cannot be group plans
       let groupWithPlan;
       let leader;
       let member;
@@ -341,6 +342,7 @@ describe('POST /groups/:groupId/leave', () => {
 
   each(typesOfGroups, (groupDetails, groupType) => {
     context(`Leaving a group with extraMonths left plan when the group is a ${groupType}`, () => {
+      if (groupDetails.privacy === 'public') return; // public guilds cannot be group plans
       const extraMonths = 12;
       let groupWithPlan;
       let member;

test/api/v3/integration/payments/stripe/POST-payments_stripe_checkout.test.js

@@ -32,7 +32,7 @@ describe('payments - stripe - #checkout', () => {
       stripePayments.checkout.restore();
     });
 
-    it('cancels a user subscription', async () => {
+    it('creates a user subscription', async () => {
       user = await generateUser({
         'profile.name': 'sender',
         'purchased.plan.customerId': 'customer-id',
@@ -48,7 +48,7 @@ describe('payments - stripe - #checkout', () => {
       expect(stripeCheckoutSubscriptionStub.args[0][0].groupId).to.eql(undefined);
     });
 
-    it('cancels a group subscription', async () => {
+    it('creates a group subscription', async () => {
       user = await generateUser({
         'profile.name': 'sender',
         'purchased.plan.customerId': 'customer-id',