Add endpoint to remove web push subscription (#32626)

spec/requests/api/web/push_subscriptions_spec.rb

@@ -0,0 +1,55 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe 'API Web Push Subscriptions' do
+  describe 'DELETE /api/web/push_subscriptions/:id' do
+    subject { delete api_web_push_subscription_path(token) }
+
+    context 'when the subscription exists' do
+      let!(:web_push_subscription) do
+        Fabricate(:web_push_subscription)
+      end
+      let(:token) do
+        web_push_subscription.generate_token_for(:unsubscribe)
+      end
+
+      it 'deletes the subscription' do
+        expect { subject }
+          .to change(Web::PushSubscription, :count).by(-1)
+
+        expect(response).to have_http_status(200)
+      end
+    end
+
+    context 'when the subscription does not exist' do
+      let(:web_push_subscription) do
+        Fabricate(:web_push_subscription)
+      end
+      let(:token) do
+        web_push_subscription.generate_token_for(:unsubscribe)
+      end
+
+      before do
+        token # memoize before destroying the record
+        web_push_subscription.destroy!
+      end
+
+      it 'does nothing' do
+        subject
+
+        expect(response).to have_http_status(200)
+      end
+    end
+
+    context 'when the token is invalid' do
+      let(:token) { 'invalid--invalid' }
+
+      it 'does nothing' do
+        subject
+
+        expect(response).to have_http_status(200)
+      end
+    end
+  end
+end