From 5443e14d7c6c105f3085966b60978d52071f8ae3 Mon Sep 17 00:00:00 2001
From: Tres Seaver <tseaver@palladion.com>
Date: Wed, 21 Sep 2016 14:01:20 -0400
Subject: [PATCH 1/3] Model/parse 'job.cancel' API response correctly.

Closes #2377.
---
 google/cloud/bigquery/job.py    |  2 +-
 unit_tests/bigquery/test_job.py | 10 ++++++----
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/google/cloud/bigquery/job.py b/google/cloud/bigquery/job.py
index a4eb745b4942..5a88f8316fdb 100644
--- a/google/cloud/bigquery/job.py
+++ b/google/cloud/bigquery/job.py
@@ -375,7 +375,7 @@ def cancel(self, client=None):
 
         api_response = client.connection.api_request(
             method='POST', path='%s/cancel' % (self.path,))
-        self._set_properties(api_response)
+        self._set_properties(api_response['job'])
 
 
 class _LoadConfiguration(object):
diff --git a/unit_tests/bigquery/test_job.py b/unit_tests/bigquery/test_job.py
index f4add8d8f7be..2d63f7b5bada 100644
--- a/unit_tests/bigquery/test_job.py
+++ b/unit_tests/bigquery/test_job.py
@@ -601,8 +601,9 @@ def test_reload_w_alternate_client(self):
 
     def test_cancel_w_bound_client(self):
         PATH = 'projects/%s/jobs/%s/cancel' % (self.PROJECT, self.JOB_NAME)
-        RESOURCE = self._makeResource()
-        conn = _Connection(RESOURCE)
+        RESOURCE = self._makeResource(ended=True)
+        RESPONSE = {'job': RESOURCE}
+        conn = _Connection(RESPONSE)
         client = _Client(project=self.PROJECT, connection=conn)
         table = _Table()
         job = self._makeOne(self.JOB_NAME, table, [self.SOURCE1], client)
@@ -617,10 +618,11 @@ def test_cancel_w_bound_client(self):
 
     def test_cancel_w_alternate_client(self):
         PATH = 'projects/%s/jobs/%s/cancel' % (self.PROJECT, self.JOB_NAME)
-        RESOURCE = self._makeResource()
+        RESOURCE = self._makeResource(ended=True)
+        RESPONSE = {'job': RESOURCE}
         conn1 = _Connection()
         client1 = _Client(project=self.PROJECT, connection=conn1)
-        conn2 = _Connection(RESOURCE)
+        conn2 = _Connection(RESPONSE)
         client2 = _Client(project=self.PROJECT, connection=conn2)
         table = _Table()
         job = self._makeOne(self.JOB_NAME, table, [self.SOURCE1], client1)

From b3f130ab8b126cbb85f40e33b604ccb6dfe156fb Mon Sep 17 00:00:00 2001
From: Tres Seaver <tseaver@palladion.com>
Date: Wed, 21 Sep 2016 14:15:55 -0400
Subject: [PATCH 2/3] Add a system test for '_AsyncJob.cancel'.

---
 system_tests/bigquery.py | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/system_tests/bigquery.py b/system_tests/bigquery.py
index c417e0538b54..f16cdf7cf056 100644
--- a/system_tests/bigquery.py
+++ b/system_tests/bigquery.py
@@ -435,3 +435,33 @@ def _job_done(instance):
         by_age = operator.itemgetter(1)
         self.assertEqual(sorted(rows, key=by_age),
                          sorted(ROWS, key=by_age))
+
+    def test_job_cancel(self):
+        DATASET_NAME = _make_dataset_name('job_cancel')
+        JOB_NAME = 'fetch_' + DATASET_NAME
+        TABLE_NAME = 'test_table'
+        QUERY = 'SELECT * FROM %s.%s' % (DATASET_NAME, TABLE_NAME)
+
+        dataset = Config.CLIENT.dataset(DATASET_NAME)
+
+        retry_403(dataset.create)()
+        self.to_delete.append(dataset)
+
+        full_name = bigquery.SchemaField('full_name', 'STRING',
+                                         mode='REQUIRED')
+        age = bigquery.SchemaField('age', 'INTEGER', mode='REQUIRED')
+        table = dataset.table(TABLE_NAME, schema=[full_name, age])
+        table.create()
+        self.to_delete.insert(0, table)
+
+        job = Config.CLIENT.run_async_query(JOB_NAME, QUERY)
+        job.begin()
+        job.cancel()
+
+        def _job_done(instance):
+            return instance.state in ('DONE', 'done')
+
+        retry = RetryInstanceState(_job_done, max_tries=8)
+        retry(job.reload)()
+
+        self.assertEqual(job.state.lower(), 'done')

From 14b8cc4486d6c018426f60f1bf1801f8c8c420da Mon Sep 17 00:00:00 2001
From: Tres Seaver <tseaver@palladion.com>
Date: Wed, 21 Sep 2016 16:44:25 -0400
Subject: [PATCH 3/3] Replace redundant 'job done' assertion with a note.

Explain why we can't make any real assertions about the status of the
cancelled job.

Addresses:
https://github.com/GoogleCloudPlatform/google-cloud-python/pull/2379#issuecomment-248700812.
---
 system_tests/bigquery.py | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/system_tests/bigquery.py b/system_tests/bigquery.py
index f16cdf7cf056..1c566b4e4e0d 100644
--- a/system_tests/bigquery.py
+++ b/system_tests/bigquery.py
@@ -464,4 +464,8 @@ def _job_done(instance):
         retry = RetryInstanceState(_job_done, max_tries=8)
         retry(job.reload)()
 
-        self.assertEqual(job.state.lower(), 'done')
+        # The `cancel` API doesn't leave any reliable traces on
+        # the status of the job resource, so we can't really assert for
+        # them here.  The best we can do is not that the API call didn't
+        # raise an error, and that the job completed (in the `retry()`
+        # above).