Adds github triggering from status updates

This adds support for triggering on github status updates.

Config schema for the github trigger has been updated to accept a list
of statuses, in the "github_user:context:status" format.

Change-Id: I15aef35716ddbcd1e66f84a73d27ca2689c936e4
Co-Authored-By: Jesse Keating <omgjlk@us.ibm.com>
Signed-off-by: Adam Gandelman <adamg@ubuntu.com>
diff --git a/tests/unit/test_github_requirements.py b/tests/unit/test_github_requirements.py
index bb9993e..a3831ff 100644
--- a/tests/unit/test_github_requirements.py
+++ b/tests/unit/test_github_requirements.py
@@ -43,3 +43,39 @@
         self.waitUntilSettled()
         self.assertEqual(len(self.history), 1)
         self.assertEqual(self.history[0].name, 'project1-pipeline')
+
+    @simple_layout('layouts/requirements-github.yaml', driver='github')
+    def test_trigger_require_status(self):
+        "Test trigger requirement: status"
+        A = self.fake_github.openFakePullRequest('org/project2', 'master', 'A')
+
+        # An error status should not cause it to be enqueued
+        A.setStatus(A.head_sha, 'error', 'null', 'null', 'check')
+        self.fake_github.emitEvent(A.getCommitStatusEvent('check',
+                                                          state='error'))
+        self.waitUntilSettled()
+        self.assertEqual(len(self.history), 0)
+
+        # An success status from unknown user should not cause it to be
+        # enqueued
+        A.setStatus(A.head_sha, 'success', 'null', 'null', 'check', user='foo')
+        self.fake_github.emitEvent(A.getCommitStatusEvent('check',
+                                                          state='success',
+                                                          user='foo'))
+        self.waitUntilSettled()
+        self.assertEqual(len(self.history), 0)
+
+        # A success status goes in
+        A.setStatus(A.head_sha, 'success', 'null', 'null', 'check')
+        self.fake_github.emitEvent(A.getCommitStatusEvent('check'))
+        self.waitUntilSettled()
+        self.assertEqual(len(self.history), 1)
+        self.assertEqual(self.history[0].name, 'project2-trigger')
+
+        # An error status for a different context should not cause it to be
+        # enqueued
+        A.setStatus(A.head_sha, 'error', 'null', 'null', 'gate')
+        self.fake_github.emitEvent(A.getCommitStatusEvent('gate',
+                                                          state='error'))
+        self.waitUntilSettled()
+        self.assertEqual(len(self.history), 1)