Add special UrlBuilder Commit handling

Commits will sometimes be wrapped in a `BatchLoader` instance, which
properly delegates `itself` to the wrapped object via `method_missing`
but not the `===` used by the `case` statement.

doc/api/commits.md

@@ -42,7 +42,8 @@ Example response:
     "message": "Replace sanitize with escape once",
     "parent_ids": [
       "6104942438c14ec7bd21c6cd5bd995272b3faff6"
-    ]
+    ],
+    "web_url": "https://gitlab.example.com/thedude/gitlab-foss/-/commit/ed899a2f4b50b4370feeea94676502b42383c746"
   },
   {
     "id": "6104942438c14ec7bd21c6cd5bd995272b3faff6",
@@ -56,7 +57,8 @@ Example response:
     "message": "Sanitize for network graph",
     "parent_ids": [
       "ae1d9fb46aa2b07ee9836d49862ec4e2c46fbbba"
-    ]
+    ],
+    "web_url": "https://gitlab.example.com/thedude/gitlab-foss/-/commit/ed899a2f4b50b4370feeea94676502b42383c746"
   }
 ]
 ```
@@ -156,7 +158,8 @@ Example response:
     "deletions": 2,
     "total": 4
   },
-  "status": null
+  "status": null,
+  "web_url": "https://gitlab.example.com/thedude/gitlab-foss/-/commit/ed899a2f4b50b4370feeea94676502b42383c746"
 }
 ```
 
@@ -235,7 +238,8 @@ Example response:
     "deletions": 10,
     "total": 25
   },
-  "status": "running"
+  "status": "running",
+  "web_url": "https://gitlab.example.com/thedude/gitlab-foss/-/commit/6104942438c14ec7bd21c6cd5bd995272b3faff6"
 }
 ```
 
@@ -314,7 +318,8 @@ Example response:
   "message": "Feature added\n\nSigned-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>\n",
   "parent_ids": [
     "a738f717824ff53aebad8b090c1b79a14f2bd9e8"
-  ]
+  ],
+  "web_url": "https://gitlab.example.com/thedude/gitlab-foss/-/commit/8b090c1b79a14f2bd9e8a738f717824ff53aebad"
 }
 ```
 
@@ -370,7 +375,8 @@ Example response:
   "authored_date":"2018-11-08T15:55:26.000Z",
   "committer_name":"Administrator",
   "committer_email":"admin@example.com",
-  "committed_date":"2018-11-08T15:55:26.000Z"
+  "committed_date":"2018-11-08T15:55:26.000Z",
+  "web_url": "https://gitlab.example.com/thedude/gitlab-foss/-/commit/8b090c1b79a14f2bd9e8a738f717824ff53aebad"
 }
 ```
 

lib/gitlab/url_builder.rb

@@ -13,7 +13,8 @@ module Gitlab
     end
 
     def url
-      case object
+      # Objects are sometimes wrapped in a BatchLoader instance
+      case object.itself
       when Commit
         commit_url
       when Issue
@@ -33,7 +34,7 @@ module Gitlab
       when User
         user_url(object)
       else
-        raise NotImplementedError.new("No URL builder defined for #{object.class}")
+        raise NotImplementedError.new("No URL builder defined for #{object.inspect}")
       end
     end
 

spec/lib/gitlab/url_builder_spec.rb

@@ -14,6 +14,18 @@ describe Gitlab::UrlBuilder do
       end
     end
 
+    context 'when passing a batch loaded Commit' do
+      it 'returns a proper URL' do
+        commit = BatchLoader.for(:commit).batch do |batch, loader|
+          batch.each { |commit| loader.call(:commit, build_stubbed(:commit)) }
+        end
+
+        url = described_class.build(commit)
+
+        expect(url).to eq "#{Settings.gitlab['url']}/#{commit.project.full_path}/-/commit/#{commit.id}"
+      end
+    end
+
     context 'when passing an Issue' do
       it 'returns a proper URL' do
         issue = build_stubbed(:issue, iid: 42)
@@ -160,7 +172,7 @@ describe Gitlab::UrlBuilder do
           project = build_stubbed(:project)
 
           expect { described_class.build(project) }
-            .to raise_error(NotImplementedError, 'No URL builder defined for Project')
+            .to raise_error(NotImplementedError, "No URL builder defined for #{project.inspect}")
         end
       end
     end