Fix Xcode project detection by looking for dirs instead of files

app/models/repository.rb

@@ -596,7 +596,7 @@ class Repository
   cache_method :gitlab_ci_yml
   def xcode_project?
-    file_on_head(:xcode_config).present?
+    file_on_head(:xcode_config, :tree).present?
   end
   cache_method :xcode_project?
@@ -920,11 +920,21 @@ class Repository
     end
   end
-  def file_on_head(type)
-    if head = tree(:head)
-      head.blobs.find do |blob|
-        Gitlab::FileDetector.type_of(blob.path) == type
+  def file_on_head(type, object_type = :blob)
+    return unless head = tree(:head)
+
+    objects =
+      case object_type
+      when :blob
+        head.blobs
+      when :tree
+        head.trees
+      else
+        raise ArgumentError, "Object type #{object_type} is not supported"
       end
+
+    objects.find do |object|
+      Gitlab::FileDetector.type_of(object.path) == type
     end
   end

lib/gitlab/file_detector.rb

@@ -14,7 +14,7 @@ module Gitlab
       avatar: /\Alogo\.(png|jpg|gif)\z/,
       issue_template: %r{\A\.gitlab/issue_templates/[^/]+\.md\z},
       merge_request_template: %r{\A\.gitlab/merge_request_templates/[^/]+\.md\z},
-      xcode_config: %r{\A[^/]*\.(xcodeproj|xcworkspace)\z},
+      xcode_config: %r{\A[^/]*\.(xcodeproj|xcworkspace)(/.+)?\z},
       # Configuration files
       gitignore: '.gitignore',

spec/models/repository_spec.rb

@@ -2021,27 +2021,27 @@ describe Repository do
   describe '#xcode_project?' do
     before do
-      allow(repository).to receive(:tree).with(:head).and_return(double(:tree, blobs: [blob]))
+      allow(repository).to receive(:tree).with(:head).and_return(double(:tree, trees: [tree]))
     end
-    context 'when the root contains a *.xcodeproj file' do
-      let(:blob) { double(:blob, path: 'Foo.xcodeproj') }
+    context 'when the root contains a *.xcodeproj directory' do
+      let(:tree) { double(:tree, path: 'Foo.xcodeproj') }
       it 'returns true' do
         expect(repository.xcode_project?).to be_truthy
       end
     end
-    context 'when the root contains a *.xcworkspace file' do
-      let(:blob) { double(:blob, path: 'Foo.xcworkspace') }
+    context 'when the root contains a *.xcworkspace directory' do
+      let(:tree) { double(:tree, path: 'Foo.xcworkspace') }
       it 'returns true' do
         expect(repository.xcode_project?).to be_truthy
       end
     end
-    context 'when the root contains no XCode config file' do
-      let(:blob) { double(:blob, path: 'subdir/Foo.xcworkspace') }
+    context 'when the root contains no Xcode config directory' do
+      let(:tree) { double(:tree, path: 'Foo') }
       it 'returns false' do
         expect(repository.xcode_project?).to be_falsey