Properly enable/disable merge button, fix tests.

app/assets/javascripts/merge_request_widget/widget_store.js.es6

@@ -23,7 +23,7 @@
 
     initWidgetState() {
       this.assignToData('showApprovals', false);
-      this.assignToData('disableAcceptance', false);
+      this.assignToData('disableAcceptance', Boolean(this.rootEl.dataset.approvalPending));
     }
 
     initApprovals() {

app/views/projects/merge_requests/widget/_open.html.haml

 - content_for :page_specific_javascripts do
   = page_specific_javascript_tag('merge_request_widget/widget_bundle.js')
 
-#merge-request-widget-app.mr-state-widget{ 'data-endpoint'=> merge_request_path(@merge_request) }
+- approval_pending = @merge_request.requires_approve? && !@merge_request.approved?
+
+#merge-request-widget-app.mr-state-widget{ 'data-endpoint'=> merge_request_path(@merge_request), 'data-approval-pending' => approval_pending }
   = render 'projects/merge_requests/widget/heading'
   .mr-widget-body
     -# After conflicts are resolved, the user is redirected back to the MR page.

features/project/merge_requests.feature

@@ -334,14 +334,14 @@ Feature: Project Merge Requests
     And I visit project "Shop" merge requests page
     And merge request 'Bug NS-04' must be approved
     And I click link "Bug NS-04"
-    And I should not see merge button
+    And I should see merge button disabled
     When I click link "Approve"
     Then I should see approved merge request "Bug NS-04"
 
   Scenario: I can not approve merge request if I am not an approver
     Given merge request 'Bug NS-04' must be approved by some user
     And I click link "Bug NS-04"
-    And I should not see merge button
+    And I should see the merge button disabled
     When I should not see Approve button
     And I should see message that MR require an approval
 

features/steps/project/merge_requests.rb

@@ -608,12 +608,19 @@ class Spinach::Features::ProjectMergeRequests < Spinach::FeatureSteps
     end
   end
 
-  step 'I should not see merge button' do
+  step 'I should see the merge button disabled' do
     page.within '.mr-state-widget' do
+      wait_for_ajax
       expect(page).to have_button('Accept Merge Request', disabled: true)
     end
   end
 
+  step 'I should not see merge button' do
+    page.within '.mr-state-widget' do
+      expect(page).not_to have_button('Accept Merge Request')
+    end
+  end
+
   step 'I should not see Approve button' do
     page.within '.mr-state-widget' do
       expect(page).not_to have_button("Approve")