Fix [Scrutinizer] error when using default branch without analysis data (#3962)

services/scrutinizer/scrutinizer-base.js

@@ -16,16 +16,17 @@ module.exports = class ScrutinizerBase extends BaseJsonService {
   }
 
   transformBranchInfo({ json, wantedBranch }) {
-    if (!wantedBranch) {
-      return json.applications[json.default_branch]
+    const branch = wantedBranch || json.default_branch
+    const noBranchInfoMessage = wantedBranch
+      ? 'branch not found'
+      : 'unavailable for default branch'
+
+    const branchInfo = json.applications[branch]
+    if (!branchInfo) {
+      throw new NotFound({ prettyMessage: noBranchInfoMessage })
     }
 
-    const branch = json.applications[wantedBranch]
-    if (!branch) {
-      throw new NotFound({ prettyMessage: ' branch not found' })
-    }
-
-    return branch
+    return branchInfo
   }
 
   transformBranchInfoMetricValue({ json, branch, metric }) {

services/scrutinizer/scrutinizer-quality.tester.js

@@ -44,3 +44,30 @@ t.create('code quality nonexistent project')
     label: 'code quality',
     message: 'project not found',
   })
+
+t.create('code quality data missing for default branch')
+  .get('/g/filp/whoops.json')
+  .intercept(nock =>
+    nock('https://scrutinizer-ci.com')
+      .get('/api/repositories/g/filp/whoops')
+      .reply(200, {
+        default_branch: 'master',
+        applications: {
+          'some-other-branch': {
+            index: {
+              _embedded: {
+                project: {
+                  metric_values: {
+                    'scrutinizer.quality': 3.4395604395604398,
+                  },
+                },
+              },
+            },
+          },
+        },
+      })
+  )
+  .expectBadge({
+    label: 'code quality',
+    message: 'unavailable for default branch',
+  })