Taskcluster: run tidy on PRs

.taskcluster.yml

@@ -2,64 +2,99 @@ version: 1
 policy:
   # https://docs.taskcluster.net/docs/reference/integrations/taskcluster-github/docs/taskcluster-yml-v1#pull-requests
   pullRequests: public
+
+  # NOTE: when updating this consider whether the daily hook needs similar changes:
+# https://tools.taskcluster.net/hooks/project-servo/daily
 tasks:
-  - $if: 'tasks_for == "github-push"'
-    then:
-      $if: >-
-        event.ref in ["refs/heads/auto", "refs/heads/try", "refs/heads/master"] ||
-        event.ref[:15] == "refs/heads/try-"
+  $let:
+    task_common:
+      provisionerId: aws-provisioner-v1
+      created: {$fromNow: ''}
+      deadline: {$fromNow: '1 day'}
+      extra:
+        treeherder:
+          machine: {platform: Linux}
+          labels: [x64]
+          symbol: Decision
+      payload:
+        maxRunTime: {$eval: '20 * 60'}
+        # https://github.com/servo/taskcluster-bootstrap-docker-images#decision-task
+        image: "servobrowser/taskcluster-bootstrap:decision-task@sha256:28045b7ec0485ef363f8cb14f194008b47e9ede99f2ea40a1e945e921fce976e"
+        features:
+          taskclusterProxy: true
+        env:
+          GIT_URL: ${event.repository.clone_url}
+          TASK_FOR: ${tasks_for}
+        command:
+          - /bin/bash
+          - '--login'
+          - '-e'
+          - '-c'
+          - >-
+            git init repo &&
+            cd repo &&
+            git fetch --depth 1 "$GIT_URL" "$GIT_REF" &&
+            git reset --hard "$GIT_SHA" &&
+            python3 etc/taskcluster/decision_task.py
+  in:
+    - $if: "tasks_for == 'github-push'"
       then:
+        $let:
+          branch:
+            $if: "event.ref[:11] == 'refs/heads/'"
+            then: "${event.ref[11:]}"
+        in:
+          $if: "branch in ['auto', 'try', 'master'] || branch[:4] == 'try-'"
+          then:
+            $mergeDeep:
+              - {$eval: "task_common"}
+              - metadata:
+                  name: "Servo: GitHub push decision task"
+                  description: ""
+                  owner: ${event.pusher.name}@users.noreply.github.com
+                  source: ${event.compare}
+                workerType: servo-docker-worker
+                scopes:
+                  - "assume:repo:github.com/servo/servo:branch:${branch}"
+                routes:
+                  $let:
+                    treeherder_repo:
+                      $if: "branch[:4] == 'try-'"
+                      then: "servo-${branch}"
+                      else: "servo-try"
+                  in:
+                    - "tc-treeherder.v2._/${treeherder_repo}.${event.after}"
+                    - "tc-treeherder-staging.v2._/${treeherder_repo}.${event.after}"
+                payload:
+                  env:
+                    GIT_REF: ${event.ref}
+                    GIT_SHA: ${event.after}
+                    TASK_OWNER: ${event.pusher.name}@users.noreply.github.com
+                    TASK_SOURCE: ${event.compare}
+    - $if: >-
+        tasks_for == 'github-pull-request' &&
+        event['action'] in ['opened', 'reopened', 'synchronize']
+      then:
+        $mergeDeep:
+          - {$eval: "task_common"}
+          - metadata:
+              name: "Servo: GitHub PR decision task"
+              description: ""
+              owner: ${event.sender.login}@users.noreply.github.com
+              source: ${event.pull_request.url}
+            workerType: servo-docker-untrusted
+            scopes:
+              - "assume:repo:github.com/servo/servo:pull-request"
+            routes:
+              - "tc-treeherder.v2._/servo-prs.${event.pull_request.head.sha}"
+              - "tc-treeherder-staging.v2._/servo-prs.${event.pull_request.head.sha}"
+            payload:
+              env:
+                # We use the merge commit made by GitHub, not the PR’s branch
+                GIT_REF: refs/pull/${event.pull_request.number}/merge
+                # `event.pull_request.merge_commit_sha` is tempting but not what we want:
+                # https://github.com/servo/servo/pull/22597#issuecomment-451518810
+                GIT_SHA: FETCH_HEAD
+                TASK_OWNER: ${event.sender.login}@users.noreply.github.com
+                TASK_SOURCE: ${event.pull_request.url}
 
-        # NOTE: when updating this consider whether the daily hook needs similar changes:
-        # https://tools.taskcluster.net/hooks/project-servo/daily
-
-        provisionerId: aws-provisioner-v1
-        workerType: servo-docker-worker
-        created: {$fromNow: ''}
-        deadline: {$fromNow: '1 day'}
-        metadata:
-          name: "Servo: GitHub push decision task"
-          description: ""
-          owner: &task_owner ${event.pusher.name}@users.noreply.github.com
-          source: &task_source ${event.compare}
-        scopes:
-          - "assume:repo:github.com/servo/servo:branch:${event.ref[11:]}"
-        routes:
-          $let:
-            treeherder_repo:
-              $if: "event.ref[:15] != 'refs/heads/try-'"
-              then: "servo-${event.ref[11:]}"
-              else: "servo-try"
-          in:
-            - "tc-treeherder.v2._/${treeherder_repo}.${event.after}"
-            - "tc-treeherder-staging.v2._/${treeherder_repo}.${event.after}"
-        extra:
-          treeherder:
-            machine: {platform: Linux}
-            labels: [x64]
-            symbol: Decision
-
-        payload:
-          maxRunTime: {$eval: '20 * 60'}
-          # https://github.com/servo/taskcluster-bootstrap-docker-images#decision-task
-          image: "servobrowser/taskcluster-bootstrap:decision-task@sha256:28045b7ec0485ef363f8cb14f194008b47e9ede99f2ea40a1e945e921fce976e"
-          features:
-            taskclusterProxy: true
-          env:
-            GIT_URL: ${event.repository.clone_url}
-            GIT_REF: ${event.ref}
-            GIT_SHA: ${event.after}
-            TASK_FOR: ${tasks_for}
-            TASK_OWNER: *task_owner
-            TASK_SOURCE: *task_source
-          command:
-            - /bin/bash
-            - '--login'
-            - '-e'
-            - '-c'
-            - >-
-              git init repo &&
-              cd repo &&
-              git fetch --depth 1 "$GIT_URL" "$GIT_REF" &&
-              git reset --hard "$GIT_SHA" &&
-              python3 etc/taskcluster/decision_task.py

etc/taskcluster/decision_task.py

@@ -10,11 +10,11 @@ from decisionlib import CONFIG, SHARED
 
 
 def main(task_for):
-    assert CONFIG.git_ref.startswith("refs/heads/")
-    branch = CONFIG.git_ref[len("refs/heads/"):]
-    CONFIG.treeherder_repository_name = "servo-" + (
-        branch if not branch.startswith("try-") else "try"
-    )
+    if CONFIG.git_ref.startswith("refs/heads/"):
+        branch = CONFIG.git_ref[len("refs/heads/"):]
+        CONFIG.treeherder_repository_name = "servo-" + (
+            branch if not branch.startswith("try-") else "try"
+        )
 
     if task_for == "github-push":
         # FIXME https://github.com/servo/servo/issues/22325 implement these:
@@ -72,6 +72,16 @@ def main(task_for):
         for function in by_branch_name.get(branch, []):
             function()
 
+    elif task_for == "github-pull-request":
+        CONFIG.treeherder_repository_name = "servo-prs"
+
+        # We want the merge commit that GitHub creates for the PR.
+        # The event does contain a `pull_request.merge_commit_sha` key, but it is wrong:
+        # https://github.com/servo/servo/pull/22597#issuecomment-451518810
+        CONFIG.git_sha_is_current_head()
+
+        tidy_untrusted()
+
     # https://tools.taskcluster.net/hooks/project-servo/daily
     elif task_for == "daily":
         daily_tasks_setup()
@@ -120,6 +130,22 @@ windows_sparse_checkout = [
 ]
 
 
+def tidy_untrusted():
+    return (
+        decisionlib.DockerWorkerTask("Tidy")
+        .with_worker_type("servo-docker-untrusted")
+        .with_treeherder("Linux x64", "Tidy")
+        .with_max_run_time_minutes(60)
+        .with_dockerfile(dockerfile_path("build"))
+        .with_env(**build_env, **unix_build_env, **linux_build_env)
+        .with_repo()
+        .with_script("""
+            ./mach test-tidy --no-progress --all
+        """)
+        .create()
+    )
+
+
 def linux_tidy_unit_docs():
     return (
         linux_build_task("Tidy + dev build + unit tests + docs")
@@ -452,7 +478,7 @@ def daily_tasks_setup():
         "expires": SHARED.from_now_json(log_artifacts_expire_in),
     })
 
-    # Unlike when reacting to a GitHub event,
+    # Unlike when reacting to a GitHub push event,
     # the commit hash is not known until we clone the repository.
     CONFIG.git_sha_is_current_head()
 
@@ -511,7 +537,6 @@ def linux_build_task(name, *, build_env=build_env):
         .with_dockerfile(dockerfile_path("build"))
         .with_env(**build_env, **unix_build_env, **linux_build_env)
         .with_repo()
-        .with_index_and_artifacts_expire_in(build_artifacts_expire_in)
     )
 
 

etc/taskcluster/mock.py

@@ -46,6 +46,9 @@ os.environ.update(**{k: k for k in "TASK_ID TASK_OWNER TASK_SOURCE GIT_URL GIT_S
 os.environ["GIT_REF"] = "refs/heads/auto"
 import decision_task
 
+print("\n# PR:")
+decision_task.main("github-pull-request")
+
 print("\n# Push:")
 decision_task.main("github-push")