Bug 1551738: Add a helper to extract the task name from the final task; r=Callek

Differential Revision: https://phabricator.services.mozilla.com/D31160

--HG--
extra : moz-landing-system : lando

taskcluster/taskgraph/task.py

@@ -46,6 +46,15 @@ class Task(object):
     def __attrs_post_init__(self):
         self.attributes['kind'] = self.kind
 
+    @property
+    def name(self):
+        if self.label.startswith(self.kind + "-"):
+            return self.label[len(self.kind)+1:]
+        elif self.label.startswith("build-docker-image-"):
+            return self.label[len("build-docker-image-"):]
+        else:
+            raise AttributeError("Task {} does not have a name.".format(self.label))
+
     def to_json(self):
         rv = {
             'kind': self.kind,

taskcluster/taskgraph/transforms/l10n.py

@@ -187,8 +187,7 @@ def setup_name(config, jobs):
         dep = job['primary-dependency']
         # Set the name to the same as the dep task, without kind name.
         # Label will get set automatically with this kinds name.
-        job['name'] = job.get('name',
-                              dep.task['metadata']['name'][len(dep.kind) + 1:])
+        job['name'] = job.get('name', dep.name)
         yield job