Add "draft" github pipeline requirement

This adds the "draft" PR status as a pipeline requirement to the
GitHub driver.  It is already used implicitly in dependent pipelines,
but this will allow it to be added explicitly to other pipelines
(for example, check).

This also fixes some minor copy/pasta errors in debug messages related
to github pipeline requirements.

Change-Id: I05f8f61aee251af24c1479274904b429baedb29d

doc/source/drivers/github.rst

@@ -551,6 +551,12 @@ enqueued into the pipeline.
       .. TODO: this could probably be expanded upon -- under what
          circumstances might this happen with github
 
+   .. attr:: draft
+
+      A boolean value (``true`` or ``false``) that indicates whether
+      or not the change must be marked as a draft in GitHub in order
+      to be enqueued.
+
    .. attr:: status
 
       A string value that corresponds with the status of the pull

releasenotes/notes/github-draft-requirement-29b4f44229bb1af1.yaml

@@ -0,0 +1,6 @@
+---
+features:
+  - |
+    The GitHub driver now supports specifying the `draft` status of a
+    PR as a pipeline requirement.
+    See :attr:`pipeline.require.<github source>.draft`.

tests/fixtures/layouts/requirements-github.yaml

@@ -285,6 +285,34 @@
       github:
         comment: true
 
+- pipeline:
+    name: require_draft
+    manager: independent
+    require:
+      github:
+        draft: true
+    trigger:
+      github:
+        - event: pull_request
+          action: changed
+    success:
+      github:
+        comment: true
+
+- pipeline:
+    name: reject_draft
+    manager: independent
+    reject:
+      github:
+        draft: true
+    trigger:
+      github:
+        - event: pull_request
+          action: changed
+    success:
+      github:
+        comment: true
+
 - pipeline:
     name: require_label
     manager: independent
@@ -390,6 +418,14 @@
     name: project16-require-check-run
     run: playbooks/project16-require-check-run.yaml
 
+- job:
+    name: project17-require-draft
+    run: playbooks/project17-require-draft.yaml
+
+- job:
+    name: project18-reject-draft
+    run: playbooks/project18-reject-draft.yaml
+
 - project:
     name: org/project1
     pipeline:
@@ -494,3 +530,15 @@
     require_check_run:
       jobs:
         - project16-require-check-run
+
+- project:
+    name: org/project17
+    require_draft:
+      jobs:
+        - project17-require-draft
+
+- project:
+    name: org/project18
+    reject_draft:
+      jobs:
+        - project18-reject-draft

tests/unit/test_github_requirements.py

@@ -502,6 +502,46 @@ class TestGithubRequirements(ZuulTestCase):
         # Event hash is not current, should trigger
         self.assertEqual(len(self.history), 1)
 
+    @simple_layout('layouts/requirements-github.yaml', driver='github')
+    def test_require_draft(self):
+
+        A = self.fake_github.openFakePullRequest('org/project17', 'master',
+                                                 'A', draft=True)
+        # A sync event that we will keep submitting to trigger
+        sync = A.getPullRequestSynchronizeEvent()
+        self.fake_github.emitEvent(sync)
+        self.waitUntilSettled()
+
+        # PR is a draft, should enqueue
+        self.assertEqual(len(self.history), 1)
+
+        # Make the PR not a draft
+        A.draft = False
+        self.fake_github.emitEvent(sync)
+        self.waitUntilSettled()
+        # PR is not a draft, should not enqueue
+        self.assertEqual(len(self.history), 1)
+
+    @simple_layout('layouts/requirements-github.yaml', driver='github')
+    def test_reject_draft(self):
+
+        A = self.fake_github.openFakePullRequest('org/project18', 'master',
+                                                 'A', draft=True)
+        # A sync event that we will keep submitting to trigger
+        sync = A.getPullRequestSynchronizeEvent()
+        self.fake_github.emitEvent(sync)
+        self.waitUntilSettled()
+
+        # PR is a draft, should not enqueue
+        self.assertEqual(len(self.history), 0)
+
+        # Make the PR not a draft
+        A.draft = False
+        self.fake_github.emitEvent(sync)
+        self.waitUntilSettled()
+        # PR is not a draft, should enqueue
+        self.assertEqual(len(self.history), 1)
+
     @simple_layout('layouts/requirements-github.yaml', driver='github')
     def test_pipeline_require_label(self):
         "Test pipeline requirement: label"

zuul/driver/github/githubmodel.py

@@ -455,11 +455,12 @@ class GithubEventFilter(EventFilter, GithubCommonFilter):
 
 
 class GithubRefFilter(RefFilter, GithubCommonFilter):
-    def __init__(self, connection_name, statuses=[], required_reviews=[],
-                 reject_reviews=[], open=None, merged=None,
-                 current_patchset=None, reject_open=None, reject_merged=None,
-                 reject_current_patchset=None, labels=[], reject_labels=[],
-                 reject_statuses=[]):
+    def __init__(self, connection_name, statuses=[],
+                 required_reviews=[], reject_reviews=[], open=None,
+                 merged=None, current_patchset=None, draft=None,
+                 reject_open=None, reject_merged=None,
+                 reject_current_patchset=None, reject_draft=None,
+                 labels=[], reject_labels=[], reject_statuses=[]):
         RefFilter.__init__(self, connection_name)
 
         GithubCommonFilter.__init__(self, required_reviews=required_reviews,
@@ -479,6 +480,10 @@ class GithubRefFilter(RefFilter, GithubCommonFilter):
             self.current_patchset = not reject_current_patchset
         else:
             self.current_patchset = current_patchset
+        if reject_draft is not None:
+            self.draft = not reject_draft
+        else:
+            self.draft = draft
         self.labels = labels
         self.reject_labels = reject_labels
 
@@ -496,12 +501,14 @@ class GithubRefFilter(RefFilter, GithubCommonFilter):
         if self.reject_reviews:
             ret += (' reject-reviews: %s' %
                     str(self.reject_reviews))
-        if self.open:
+        if self.open is not None:
             ret += ' open: %s' % self.open
-        if self.merged:
+        if self.merged is not None:
             ret += ' merged: %s' % self.merged
-        if self.current_patchset:
+        if self.current_patchset is not None:
             ret += ' current-patchset: %s' % self.current_patchset
+        if self.draft is not None:
+            ret += ' draft: %s' % self.draft
         if self.labels:
             ret += ' labels: %s' % self.labels
         if self.reject_labels:
@@ -521,7 +528,8 @@ class GithubRefFilter(RefFilter, GithubCommonFilter):
             # and cannot possibly pass this test.
             if hasattr(change, 'number'):
                 if self.open != change.open:
-                    return FalseWithReason("Change is not a PR")
+                    return FalseWithReason(
+                        "Change does not match open requirement")
             else:
                 return FalseWithReason("Change is not a PR")
 
@@ -530,7 +538,8 @@ class GithubRefFilter(RefFilter, GithubCommonFilter):
             # and cannot possibly pass this test.
             if hasattr(change, 'number'):
                 if self.merged != change.is_merged:
-                    return FalseWithReason("Change is not a PR")
+                    return FalseWithReason(
+                        "Change does not match merged requirement")
             else:
                 return FalseWithReason("Change is not a PR")
 
@@ -539,7 +548,18 @@ class GithubRefFilter(RefFilter, GithubCommonFilter):
             # and cannot possibly pass this test.
             if hasattr(change, 'number'):
                 if self.current_patchset != change.is_current_patchset:
-                    return FalseWithReason("Change is not current")
+                    return FalseWithReason(
+                        "Change does not match current-patchset requirement")
+            else:
+                return FalseWithReason("Change is not a PR")
+
+        if self.draft is not None:
+            # if a "change" has no number, it's not a change, but a push
+            # and cannot possibly pass this test.
+            if hasattr(change, 'number'):
+                if self.draft != change.draft:
+                    return FalseWithReason(
+                        "Change does not match draft requirement")
             else:
                 return FalseWithReason("Change is not a PR")
 

zuul/driver/github/githubsource.py

@@ -169,6 +169,7 @@ class GithubSource(BaseSource):
             open=config.get('open'),
             merged=config.get('merged'),
             current_patchset=config.get('current-patchset'),
+            draft=config.get('draft'),
             labels=to_list(config.get('label')),
         )
         return [f]
@@ -182,6 +183,7 @@ class GithubSource(BaseSource):
             reject_open=config.get('open'),
             reject_merged=config.get('merged'),
             reject_current_patchset=config.get('current-patchset'),
+            reject_draft=config.get('draft'),
         )
         return [f]
 
@@ -207,6 +209,7 @@ def getRequireSchema():
                'open': bool,
                'merged': bool,
                'current-patchset': bool,
+               'draft': bool,
                'label': scalar_or_list(str)}
     return require
 
@@ -217,5 +220,6 @@ def getRejectSchema():
               'open': bool,
               'merged': bool,
               'current-patchset': bool,
+              'draft': bool,
               'label': scalar_or_list(str)}
     return reject