Address reviewer feedback

- test full Jira error messages (including links)
- Test Jira alert snapshots (frontend)

ee/spec/frontend/external_issues_list/components/__snapshots__/external_issues_list_root_spec.js.snap

 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
+exports[`ExternalIssuesListRoot error handling when request fails displays error alert with "API error" when API responds with "["API <a href=\\"gitlab.com\\">error</a>"]" 1`] = `"<span>API <a href=\\"gitlab.com\\">error</a></span>"`;
+
+exports[`ExternalIssuesListRoot error handling when request fails displays error alert with "API error" when API responds with "["API error"]" 1`] = `"<span>API error</span>"`;
+
+exports[`ExternalIssuesListRoot error handling when request fails displays error alert with "API" when API responds with "["API <script src=\\"hax0r.xyz\\">error</script>"]" 1`] = `"<span>API </span>"`;
+
+exports[`ExternalIssuesListRoot error handling when request fails displays error alert with "An error occurred while loading issues" when API responds with "undefined" 1`] = `"<span>An error occurred while loading issues</span>"`;
+
 exports[`ExternalIssuesListRoot when request succeeds renders issuable-list component with correct props 1`] = `
 Object {
   "currentPage": 1,

ee/spec/frontend/external_issues_list/components/external_issues_list_root_spec.js

@@ -63,6 +63,7 @@ describe('ExternalIssuesListRoot', () => {
 
   const findIssuableList = () => wrapper.findComponent(IssuableList);
   const findAlert = () => wrapper.findComponent(GlAlert);
+  const findAlertMessage = () => findAlert().find('span');
   const createLabelFilterEvent = (data) => ({ type: 'labels', value: { data } });
   const createSearchFilterEvent = (data) => ({ type: 'filtered-search-term', value: { data } });
 
@@ -319,14 +320,14 @@ describe('ExternalIssuesListRoot', () => {
 
     describe('when request fails', () => {
       it.each`
-        APIErrors                                         | expectedRenderedErrorMessage
+        APIErrors                                         | expectedRenderedErrorText
         ${['API error']}                                  | ${'API error'}
         ${['API <a href="gitlab.com">error</a>']}         | ${'API error'}
         ${['API <script src="hax0r.xyz">error</script>']} | ${'API'}
         ${undefined}                                      | ${i18n.errorFetchingIssues}
       `(
-        'displays error alert with "$expectedRenderedErrorMessage" when API responds with "$APIErrors"',
-        async ({ APIErrors, expectedRenderedErrorMessage }) => {
+        'displays error alert with "$expectedRenderedErrorText" when API responds with "$APIErrors"',
+        async ({ APIErrors, expectedRenderedErrorText }) => {
           jest.spyOn(axios, 'get');
           mock
             .onGet(mockProvide.issuesFetchPath)
@@ -335,7 +336,8 @@ describe('ExternalIssuesListRoot', () => {
           createComponent();
           await waitForPromises();
 
-          expectErrorHandling(expectedRenderedErrorMessage);
+          expectErrorHandling(expectedRenderedErrorText);
+          expect(findAlertMessage().html()).toMatchSnapshot();
         },
       );
     });

spec/graphql/resolvers/projects/jira_projects_resolver_spec.rb

@@ -90,7 +90,10 @@ RSpec.describe Resolvers::Projects::JiraProjectsResolver do
           end
 
           it 'raises failure error' do
-            expect { resolve_jira_projects }.to raise_error(/^An error occurred while requesting data from Jira: Some failure\..*/)
+            config_docs_link_url = Rails.application.routes.url_helpers.help_page_path('integration/jira/configure')
+            docs_link_start = '<a href="%{url}" target="_blank" rel="noopener noreferrer">'.html_safe % { url: config_docs_link_url }
+            error_message = 'An error occurred while requesting data from Jira: Some failure. Check your %{docs_link_start}Jira integration configuration</a> and try again.' % { docs_link_start: docs_link_start }
+            expect { resolve_jira_projects }.to raise_error(error_message)
           end
         end
       end

spec/support/shared_examples/services/jira/requests/base_shared_examples.rb

@@ -31,6 +31,9 @@ RSpec.shared_examples 'a service that handles Jira API errors' do
   end
 
   context 'when the JSON in JIRA::HTTPError is unsafe' do
+    config_docs_link_url = Rails.application.routes.url_helpers.help_page_path('integration/jira/configure')
+    let(:docs_link_start) { '<a href="%{url}" target="_blank" rel="noopener noreferrer">'.html_safe % { url: config_docs_link_url } }
+
     before do
       stub_client_and_raise(JIRA::HTTPError, error)
     end
@@ -39,7 +42,8 @@ RSpec.shared_examples 'a service that handles Jira API errors' do
       let(:error) { '{"errorMessages":' }
 
       it 'returns the default error message' do
-        expect(subject.message).to start_with('An error occurred while requesting data from Jira.')
+        error_message = 'An error occurred while requesting data from Jira. Check your %{docs_link_start}Jira integration configuration</a> and try again.' % { docs_link_start: docs_link_start }
+        expect(subject.message).to eq(error_message)
       end
     end
 
@@ -47,7 +51,8 @@ RSpec.shared_examples 'a service that handles Jira API errors' do
       let(:error) { '{"errorMessages":["<script>alert(true)</script>foo"]}' }
 
       it 'sanitizes it' do
-        expect(subject.message).to start_with('An error occurred while requesting data from Jira: foo')
+        error_message = 'An error occurred while requesting data from Jira: foo. Check your %{docs_link_start}Jira integration configuration</a> and try again.' % { docs_link_start: docs_link_start }
+        expect(subject.message).to eq(error_message)
       end
     end
   end