1 files changed, 122 insertions, 8 deletions

diff --git a/spec/lib/gitlab/ci/config/yaml_spec.rb b/spec/lib/gitlab/ci/config/yaml_spec.rb
index f4b70069bbe..beb872071d2 100644
--- a/spec/lib/gitlab/ci/config/yaml_spec.rb
+++ b/spec/lib/gitlab/ci/config/yaml_spec.rb
@@ -113,18 +113,85 @@ RSpec.describe Gitlab::Ci::Config::Yaml, feature_category: :pipeline_composition
   end
 
   describe '.load_result!' do
+    let_it_be(:project) { create(:project) }
+
+    subject(:result) { described_class.load_result!(yaml, project: project) }
+
     context 'when syntax is invalid' do
       let(:yaml) { 'some: invalid: syntax' }
 
       it 'returns an invalid result object' do
-        result = described_class.load_result!(yaml)
-
         expect(result).not_to be_valid
         expect(result.error).to be_a ::Gitlab::Config::Loader::FormatError
       end
     end
 
-    context 'when syntax is valid and contains a header document' do
+    context 'when the first document is a header' do
+      context 'with explicit document start marker' do
+        let(:yaml) do
+          <<~YAML
+            ---
+            spec:
+            ---
+            b: 2
+          YAML
+        end
+
+        it 'considers the first document as header and the second as content' do
+          expect(result).to be_valid
+          expect(result.error).to be_nil
+          expect(result.header).to eq({ spec: nil })
+          expect(result.content).to eq({ b: 2 })
+        end
+      end
+    end
+
+    context 'when first document is empty' do
+      let(:yaml) do
+        <<~YAML
+          ---
+          ---
+          b: 2
+        YAML
+      end
+
+      it 'considers the first document as header and the second as content' do
+        expect(result).not_to have_header
+      end
+    end
+
+    context 'when first document is an empty hash' do
+      let(:yaml) do
+        <<~YAML
+          {}
+          ---
+          b: 2
+        YAML
+      end
+
+      it 'returns second document as a content' do
+        expect(result).not_to have_header
+        expect(result.content).to eq({ b: 2 })
+      end
+    end
+
+    context 'when first an array' do
+      let(:yaml) do
+        <<~YAML
+          ---
+           - a
+           - b
+          ---
+          b: 2
+        YAML
+      end
+
+      it 'considers the first document as header and the second as content' do
+        expect(result).not_to have_header
+      end
+    end
+
+    context 'when the first document is not a header' do
       let(:yaml) do
         <<~YAML
           a: 1
@@ -133,15 +200,62 @@ RSpec.describe Gitlab::Ci::Config::Yaml, feature_category: :pipeline_composition
         YAML
       end
 
-      let(:project) { create(:project) }
+      it 'considers the first document as content for backwards compatibility' do
+        expect(result).to be_valid
+        expect(result.error).to be_nil
+        expect(result).not_to have_header
+        expect(result.content).to eq({ a: 1 })
+      end
+
+      context 'with explicit document start marker' do
+        let(:yaml) do
+          <<~YAML
+            ---
+            a: 1
+            ---
+            b: 2
+          YAML
+        end
+
+        it 'considers the first document as content for backwards compatibility' do
+          expect(result).to be_valid
+          expect(result.error).to be_nil
+          expect(result).not_to have_header
+          expect(result.content).to eq({ a: 1 })
+        end
+      end
+    end
 
-      it 'returns a result object' do
-        result = described_class.load_result!(yaml, project: project)
+    context 'when the first document is not a header and second document is empty' do
+      let(:yaml) do
+        <<~YAML
+          a: 1
+          ---
+        YAML
+      end
 
+      it 'considers the first document as content' do
         expect(result).to be_valid
         expect(result.error).to be_nil
-        expect(result.header).to eq({ a: 1 })
-        expect(result.content).to eq({ b: 2 })
+        expect(result).not_to have_header
+        expect(result.content).to eq({ a: 1 })
+      end
+
+      context 'with explicit document start marker' do
+        let(:yaml) do
+          <<~YAML
+            ---
+            a: 1
+            ---
+          YAML
+        end
+
+        it 'considers the first document as content' do
+          expect(result).to be_valid
+          expect(result.error).to be_nil
+          expect(result).not_to have_header
+          expect(result.content).to eq({ a: 1 })
+        end
       end
     end
   end