Check overall_approvals_required for approved?

This is useful for maintainer to set project-wide restriction on
number of approvals required, but let MR author choose whom to approve.

Change any_approval_allowed? as it now has different meaning
to approved?

ee/app/models/approval_state.rb

@@ -10,7 +10,7 @@ class ApprovalState
 
   attr_reader :merge_request, :project
 
-  def_delegators :@merge_request, :merge_status, :approved_by_users
+  def_delegators :@merge_request, :merge_status, :approved_by_users, :approvals
   alias_method :approved_approvers, :approved_by_users
 
   def initialize(merge_request)
@@ -48,12 +48,19 @@ class ApprovalState
     !approved?
   end
 
+  def overall_approvals_required
+    @overall_approvals_required ||= project.approvals_before_merge
+  end
+
   def approved?
     strong_memoize(:approved) do
-      wrapped_approval_rules.all?(&:approved?)
+      (overall_approvals_required == 0 || approvals.size >= overall_approvals_required) && wrapped_approval_rules.all?(&:approved?)
     end
   end
-  alias_method :any_approver_allowed?, :approved?
+
+  def any_approver_allowed?
+    approved? || overall_approvals_required > approvers.size
+  end
 
   # Number of approvals remaining (excluding existing approvals) before the MR is
   # considered approved.

ee/spec/models/approval_state_spec.rb

@@ -97,6 +97,16 @@ describe ApprovalState do
 
           expect(subject.approval_needed?).to eq(false)
         end
+
+        context 'when overall_approvals_required is not met' do
+          before do
+            project.update(approvals_before_merge: 1)
+          end
+
+          it 'returns false' do
+            expect(subject.approved?).to eq(false)
+          end
+        end
       end
 
       context 'when not approved' do
@@ -136,6 +146,38 @@ describe ApprovalState do
       end
     end
 
+    describe '#any_approver_allowed?' do
+      context 'when approved' do
+        before do
+          allow(subject).to receive(:approved?).and_return(true)
+        end
+
+        it 'returns true' do
+          expect(subject.any_approver_allowed?).to eq(true)
+        end
+      end
+
+      context 'when not approved' do
+        before do
+          allow(subject).to receive(:approved?).and_return(false)
+        end
+
+        it 'returns false' do
+          expect(subject.approved?).to eq(false)
+        end
+
+        context 'when overall_approvals_required cannot be met' do
+          before do
+            project.update(approvals_before_merge: 1)
+          end
+
+          it 'returns false' do
+            expect(subject.any_approver_allowed?).to eq(true)
+          end
+        end
+      end
+    end
+
     describe '#approvals_left' do
       before do
         create_rule(approvals_required: 5)
@@ -585,6 +627,16 @@ describe ApprovalState do
         it 'returns true' do
           expect(subject.approved?).to eq(true)
         end
+
+        context 'when overall_approvals_required is not met' do
+          before do
+            project.update(approvals_before_merge: 1)
+          end
+
+          it 'returns false' do
+            expect(subject.approved?).to eq(false)
+          end
+        end
       end
 
       context 'when some rules are not approved' do
@@ -598,6 +650,38 @@ describe ApprovalState do
       end
     end
 
+    describe '#any_approver_allowed?' do
+      context 'when approved' do
+        before do
+          allow(subject).to receive(:approved?).and_return(true)
+        end
+
+        it 'returns true' do
+          expect(subject.any_approver_allowed?).to eq(true)
+        end
+      end
+
+      context 'when not approved' do
+        before do
+          allow(subject).to receive(:approved?).and_return(false)
+        end
+
+        it 'returns false' do
+          expect(subject.approved?).to eq(false)
+        end
+
+        context 'when overall_approvals_required cannot be met' do
+          before do
+            project.update(approvals_before_merge: 1)
+          end
+
+          it 'returns false' do
+            expect(subject.any_approver_allowed?).to eq(true)
+          end
+        end
+      end
+    end
+
     describe '#approvals_left' do
       let(:rule1) { create_unapproved_rule(approvals_required: 5) }
       let(:rule2) { create_unapproved_rule(approvals_required: 7) }