Merge branch '24779-last-deployment-call-on-nil-environment-fix' into 'master'

changes environment.last_deployment to a try expression so it does not fail if e…

## What does this MR do?

Fixes the call on `environment.last_deployment` to not break when `environment`is not yet set.

## Does this MR meet the acceptance criteria?

- [x] [Changelog entry](https://docs.gitlab.com/ce/development/changelog.html) added
- [x] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [x] API support added
- Tests
  - [x] Added for this feature/bug
  - [x] All builds are passing
- [x] Conform by the [merge request performance guides](http://docs.gitlab.com/ce/development/merge_request_performance_guidelines.html)
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if it does - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

## What are the relevant issue numbers?


Closes #24779

See merge request !7671

3 files changed, 48 insertions, 13 deletions

diff --git a/app/views/projects/builds/show.html.haml b/app/views/projects/builds/show.html.haml
index d8cbfd7173a..108674dbba6 100644
--- a/app/views/projects/builds/show.html.haml
+++ b/app/views/projects/builds/show.html.haml
@@ -40,13 +40,12 @@
               This build is the most recent deployment to #{environment_link_for_build(@build.project, @build)}.
             - else
               This build is an out-of-date deployment to #{environment_link_for_build(@build.project, @build)}.
-              - if environment.last_deployment
-                View the most recent deployment #{deployment_link(environment.last_deployment)}.
+              View the most recent deployment #{deployment_link(environment.last_deployment)}.
           - elsif @build.complete? && !@build.success?
             The deployment of this build to #{environment_link_for_build(@build.project, @build)} did not succeed.
           - else
             This build is creating a deployment to #{environment_link_for_build(@build.project, @build)}
-            - if environment.last_deployment
+            - if environment.try(:last_deployment)
               and will overwrite the
               = link_to 'latest deployment', deployment_link(environment.last_deployment)
 
diff --git a/changelogs/unreleased/24779-last-deployment-call-on-nil-environment-fix.yml b/changelogs/unreleased/24779-last-deployment-call-on-nil-environment-fix.yml
new file mode 100644
index 00000000000..5e7580fb8f2
--- /dev/null
+++ b/changelogs/unreleased/24779-last-deployment-call-on-nil-environment-fix.yml
@@ -0,0 +1,4 @@
+---
+title: fixes last_deployment call environment is nil
+merge_request: 7671
+author: 
diff --git a/spec/views/projects/builds/show.html.haml_spec.rb b/spec/views/projects/builds/show.html.haml_spec.rb
index e0c77201116..745d0c745bd 100644
--- a/spec/views/projects/builds/show.html.haml_spec.rb
+++ b/spec/views/projects/builds/show.html.haml_spec.rb
@@ -88,16 +88,46 @@ describe 'projects/builds/show', :view do
         create(:ci_build, :running, environment: 'staging', pipeline: pipeline)
       end
 
-      let!(:environment) do
-        create(:environment, name: 'staging', project: project)
-      end
-
-      it 'shows deployment message' do
-        expected_text = 'This build is creating a deployment to staging'
-        render
-
-        expect(rendered).to have_css(
-          '.environment-information', text: expected_text)
+      context 'when environment exists' do
+        let!(:environment) do
+          create(:environment, name: 'staging', project: project)
+        end
+
+        it 'shows deployment message' do
+          expected_text = 'This build is creating a deployment to staging'
+          render
+
+          expect(rendered).to have_css(
+            '.environment-information', text: expected_text)
+        end
+
+        context 'when it has deployment' do
+          let!(:deployment) do
+            create(:deployment, environment: environment)
+          end
+
+          it 'shows that deployment will be overwritten' do
+            expected_text = 'This build is creating a deployment to staging'
+            render
+
+            expect(rendered).to have_css(
+              '.environment-information', text: expected_text)
+            expect(rendered).to have_css(
+              '.environment-information', text: 'latest deployment')
+          end
+        end
+      end
+
+      context 'when environment does not exist' do
+        it 'shows deployment message' do
+          expected_text = 'This build is creating a deployment to staging'
+          render
+
+          expect(rendered).to have_css(
+            '.environment-information', text: expected_text)
+          expect(rendered).not_to have_css(
+            '.environment-information', text: 'latest deployment')
+        end
       end
     end
 
@@ -134,6 +164,8 @@ describe 'projects/builds/show', :view do
 
         expect(rendered).to have_css(
           '.environment-information', text: expected_text)
+        expect(rendered).not_to have_css(
+          '.environment-information', text: 'latest deployment')
       end
     end
   end