github: create/preview reactions on pull review request comments

for snarfed/bridgy#955

README.md

@@ -317,6 +317,7 @@ Changelog
   * Add support for adding tags to existing photos ([bridgy#857](https://github.com/snarfed/bridgy/issues/857)).
 * GitHub:
   * Handle [HTTP 451 Unavailable for Legal Reasons](https://en.wikipedia.org/wiki/HTTP_451) responses ([eg for DMCA takedowns](https://developer.github.com/changes/2016-03-17-the-451-status-code-is-now-supported/)) gracefully.
+  * Add create/preview support for reactions on pull review request comments (ie URLs with `#discussion_r...` fragments).
 * HTML/microformats2:
   * Add `aria-hidden="true"` to empty links ([bridgy#947](https://github.com/snarfed/bridgy/issues/947)).
   * Bug fix: escape `&`, `<`, and `>` characters in bare mf2 `content` properties ([aaronpk/XRay#102](https://github.com/aaronpk/XRay/issues/102)).

granary/github.py

@@ -25,8 +25,8 @@
 REST_API_ISSUE_LABELS = REST_API_BASE + '/repos/%s/%s/issues/%s/labels'
 REST_API_COMMENTS = REST_API_BASE + '/repos/%s/%s/issues/%s/comments'
 REST_API_REACTIONS = REST_API_BASE + '/repos/%s/%s/issues/%s/reactions'
-REST_API_COMMENT = REST_API_BASE + '/repos/%s/%s/issues/comments/%s'
-REST_API_COMMENT_REACTIONS = REST_API_BASE + '/repos/%s/%s/issues/comments/%s/reactions'
+REST_API_COMMENT = REST_API_BASE + '/repos/%s/%s/%s/comments/%s'
+REST_API_COMMENT_REACTIONS = REST_API_BASE + '/repos/%s/%s/%s/comments/%s/reactions'
 REST_API_MARKDOWN = REST_API_BASE + '/markdown'
 REST_API_NOTIFICATIONS = REST_API_BASE + '/notifications?all=true&participating=true'
 GRAPHQL_BASE = 'https://api.github.com/graphql'
@@ -446,14 +446,16 @@ def get_comment(self, comment_id, **kwargs):
 
     Returns: dict, an ActivityStreams comment object
     """
-    parts = tuple(comment_id.split(':'))
+    parts = comment_id.split(':')
     if len(parts) != 3:
       raise ValueError('GitHub comment ids must be of the form USER:REPO:COMMENT_ID')
 
-    if util.is_int(parts[2]):  # REST API id
-      comment = self.rest(REST_API_COMMENT % parts)
+    id = parts[-1]
+    if util.is_int(id):  # REST API id
+      parts.insert(2, 'issues')
+      comment = self.rest(REST_API_COMMENT % tuple(parts))
     else:  # GraphQL node id
-      comment = self.graphql(GRAPHQL_COMMENT, {'id': parts[2]})['node']
+      comment = self.graphql(GRAPHQL_COMMENT, {'id': id})['node']
 
     return self.comment_to_object(comment)
 
@@ -561,9 +563,14 @@ def _create(self, obj, preview=None, include_link=source.OMIT_LINK,
     if len(path) == 4:
       number = path[3]
 
-    comment_id = re.match(r'^issuecomment-([0-9]+)$', parsed.fragment)
+    # TODO: support #pullrequestreview-* URLs for top-level PR comments too.
+    # Haven't yet gotten those to work via either the issues or pulls APIs.
+    # https://github.com/snarfed/bridgy/issues/955#issuecomment-788478848
+    comment_id = re.match(r'^(discussion_r|issuecomment-)([0-9]+)$', parsed.fragment)
+    comment_type = None
     if comment_id:
-      comment_id = comment_id.group(1)
+      comment_type = 'issues' if comment_id.group(1) == 'issuecomment-' else 'pulls'
+      comment_id = comment_id.group(2)
     elif parsed.fragment:
       return source.creation_result(
         abort=True,
@@ -578,7 +585,8 @@ def _create(self, obj, preview=None, include_link=source.OMIT_LINK,
       is_reaction = orig_content in REACTIONS_GRAPHQL
       if preview:
         if comment_id:
-          comment = self.rest(REST_API_COMMENT % (owner, repo, comment_id))
+          comment = self.rest(REST_API_COMMENT % (owner, repo, comment_type,
+                                                  comment_id))
           target_link = '<a href="%s">a comment on %s/%s#%s, <em>%s</em></a>' % (
             base_url, owner, repo, number, util.ellipsize(comment['body']))
         else:
@@ -604,7 +612,8 @@ def _create(self, obj, preview=None, include_link=source.OMIT_LINK,
         # https://github.com/snarfed/bridgy/issues/824
         if is_reaction:
           if comment_id:
-            api_url = REST_API_COMMENT_REACTIONS % (owner, repo, comment_id)
+            api_url = REST_API_COMMENT_REACTIONS % (owner, repo, comment_type,
+                                                    comment_id)
             reacted = self.rest(api_url, data={
               'content': REACTIONS_REST.get(orig_content),
             })

granary/tests/test_github.py

@@ -633,7 +633,7 @@ def test_issue_to_object_empty(self):
     self.assert_equals({}, self.gh.issue_to_object({}))
 
   def test_get_comment_rest(self):
-    self.expect_rest(REST_API_COMMENT % ('foo', 'bar', 123), COMMENT_REST)
+    self.expect_rest(REST_API_COMMENT % ('foo', 'bar', 'issues', 123), COMMENT_REST)
     self.mox.ReplayAll()
     self.assert_equals(COMMENT_OBJ, self.gh.get_comment('foo:bar:123'))
 
@@ -1066,9 +1066,10 @@ def test_preview_reaction_issue(self):
     preview = self.gh.preview_create(REACTION_OBJ_INPUT)
     self.assertEqual(u'<span class="verb">react 👍</span> to <a href="https://github.com/foo/bar/pull/123">foo/bar#123, <em>an issue title</em></a>.', preview.description)
 
-  def test_create_reaction_comment(self):
+  def test_create_reaction_issue_comment(self):
     self.expect_requests_post(
-      REST_API_COMMENT_REACTIONS % ('foo', 'bar', 456), headers=EXPECTED_HEADERS,
+      REST_API_COMMENT_REACTIONS % ('foo', 'bar', 'issues', 456),
+      headers=EXPECTED_HEADERS,
       json={
         'content': '+1',
       }, response={
@@ -1085,8 +1086,8 @@ def test_create_reaction_comment(self):
       'type': 'react',
     }, result.content, result)
 
-  def test_preview_reaction_comment(self):
-    self.expect_rest(REST_API_COMMENT % ('foo', 'bar', 456), COMMENT_REST)
+  def test_preview_reaction_issue_comment(self):
+    self.expect_rest(REST_API_COMMENT % ('foo', 'bar', 'issues', 456), COMMENT_REST)
     self.mox.ReplayAll()
 
     preview = self.gh.preview_create(COMMENT_REACTION_OBJ_INPUT)