Bug 2003628 - Support Github pull requests in Enterprise Firefox

Author: ahal

.taskcluster.yml

@@ -340,7 +340,7 @@ tasks:
                                       then:
                                           matrixBody: "${repository.project} push notification: https://treeherder.mozilla.org/#/jobs?repo=${repository.project}&revision=${push.revision}"
     # Decision task for events originating from Github
-    - $if: 'tasks_for in ["github-push"]'
+    - $if: 'tasks_for in ["github-push", "github-pull-request"]'
       then:
           $let:
               $merge:
@@ -355,6 +355,14 @@ tasks:
                             ref: '${event.ref}'
                             baseRev: '${event.before}'
                             headRev: '${event.after}'
+                        'tasks_for[:19] == "github-pull-request"':
+                            ownerEmail:  '${event.pull_request.user.login}@users.noreply.github.com'
+                            baseRepoUrl:  '${event.pull_request.base.repo.html_url}'
+                            repoUrl:  '${event.pull_request.head.repo.html_url}'
+                            project:  '${event.pull_request.base.repo.name}'
+                            ref: '${event.pull_request.head.ref}'
+                            baseRev: '${event.pull_request.base.sha}'
+                            headRev: '${event.pull_request.head.sha}'
           in:
               $let:
                   shortRef:
@@ -363,7 +371,8 @@ tasks:
                       else: ${ref}
               in:
                   $if: >
-                    tasks_for == "github-push" && shortRef in ["enterprise-main", "enterprise-try"]
+                    tasks_for == "github-push" && shortRef == "enterprise-main"
+                    || (isPullRequest && pullRequestAction in ["opened", "reopened", "synchronize"])
                   then:
                       $let:
                           level: