1 files changed, 227 insertions, 0 deletions
diff --git a/spec/lib/gitlab/ci/config/extendable/entry_spec.rb b/spec/lib/gitlab/ci/config/extendable/entry_spec.rb
new file mode 100644
index 00000000000..0a148375d11
--- /dev/null
+++ b/spec/lib/gitlab/ci/config/extendable/entry_spec.rb
@@ -0,0 +1,227 @@
+require 'fast_spec_helper'
+
+describe Gitlab::Ci::Config::Extendable::Entry do
+  describe '.new' do
+    context 'when entry key is not included in the context hash' do
+      it 'raises error' do
+        expect { described_class.new(:test, something: 'something') }
+          .to raise_error StandardError, 'Invalid entry key!'
+      end
+    end
+  end
+
+  describe '#value' do
+    it 'reads a hash value from the context' do
+      entry = described_class.new(:test, test: 'something')
+
+      expect(entry.value).to eq 'something'
+    end
+  end
+
+  describe '#extensible?' do
+    context 'when entry has inheritance defined' do
+      it 'is extensible' do
+        entry = described_class.new(:test, test: { extends: 'something' })
+
+        expect(entry).to be_extensible
+      end
+    end
+
+    context 'when entry does not have inheritance specified' do
+      it 'is not extensible' do
+        entry = described_class.new(:test, test: { script: 'something' })
+
+        expect(entry).not_to be_extensible
+      end
+    end
+
+    context 'when entry value is not a hash' do
+      it 'is not extensible' do
+        entry = described_class.new(:test, test: 'something')
+
+        expect(entry).not_to be_extensible
+      end
+    end
+  end
+
+  describe '#extends_key' do
+    context 'when entry is extensible' do
+      it 'returns symbolized extends key value' do
+        entry = described_class.new(:test, test: { extends: 'something' })
+
+        expect(entry.extends_key).to eq :something
+      end
+    end
+
+    context 'when entry is not extensible' do
+      it 'returns nil' do
+        entry = described_class.new(:test, test: 'something')
+
+        expect(entry.extends_key).to be_nil
+      end
+    end
+  end
+
+  describe '#ancestors' do
+    let(:parent) do
+      described_class.new(:test, test: { extends: 'something' })
+    end
+
+    let(:child) do
+      described_class.new(:job, { job: { script: 'something' } }, parent)
+    end
+
+    it 'returns ancestors keys' do
+      expect(child.ancestors).to eq [:test]
+    end
+  end
+
+  describe '#base_hash!' do
+    subject { described_class.new(:test, hash) }
+
+    context 'when base hash is not extensible' do
+      let(:hash) do
+        {
+          template: { script: 'rspec' },
+          test: { extends: 'template' }
+        }
+      end
+
+      it 'returns unchanged base hash' do
+        expect(subject.base_hash!).to eq(script: 'rspec')
+      end
+    end
+
+    context 'when base hash is extensible too' do
+      let(:hash) do
+        {
+          first: { script: 'rspec' },
+          second: { extends: 'first' },
+          test: { extends: 'second' }
+        }
+      end
+
+      it 'extends the base hash first' do
+        expect(subject.base_hash!).to eq(extends: 'first', script: 'rspec')
+      end
+
+      it 'mutates original context' do
+        subject.base_hash!
+
+        expect(hash.fetch(:second)).to eq(extends: 'first', script: 'rspec')
+      end
+    end
+  end
+
+  describe '#extend!' do
+    subject { described_class.new(:test, hash) }
+
+    context 'when extending a non-hash value' do
+      let(:hash) do
+        {
+          first: 'my value',
+          test: { extends: 'first' }
+        }
+      end
+
+      it 'raises an error' do
+        expect { subject.extend! }
+          .to raise_error(described_class::InvalidExtensionError,
+                          /invalid base hash/)
+      end
+    end
+
+    context 'when extending unknown key' do
+      let(:hash) do
+        { test: { extends: 'something' } }
+      end
+
+      it 'raises an error' do
+        expect { subject.extend! }
+          .to raise_error(described_class::InvalidExtensionError,
+                          /unknown key/)
+      end
+    end
+
+    context 'when extending a hash correctly' do
+      let(:hash) do
+        {
+          first: { script: 'my value' },
+          second: { extends: 'first' },
+          test: { extends: 'second' }
+        }
+      end
+
+      let(:result) do
+        {
+          first: { script: 'my value' },
+          second: { extends: 'first', script: 'my value' },
+          test: { extends: 'second', script: 'my value' }
+        }
+      end
+
+      it 'returns extended part of the hash' do
+        expect(subject.extend!).to eq result[:test]
+      end
+
+      it 'mutates original context' do
+        subject.extend!
+
+        expect(hash).to eq result
+      end
+    end
+
+    context 'when hash is not extensible' do
+      let(:hash) do
+        {
+          first: { script: 'my value' },
+          second: { extends: 'first' },
+          test: { value: 'something' }
+        }
+      end
+
+      it 'returns original key value' do
+        expect(subject.extend!).to eq(value: 'something')
+      end
+
+      it 'does not mutate orignal context' do
+        original = hash.deep_dup
+
+        subject.extend!
+
+        expect(hash).to eq original
+      end
+    end
+
+    context 'when circular depenency gets detected' do
+      let(:hash) do
+        { test: { extends: 'test' } }
+      end
+
+      it 'raises an error' do
+        expect { subject.extend! }
+          .to raise_error(described_class::CircularDependencyError,
+                          /circular dependency detected/)
+      end
+    end
+
+    context 'when nesting level is too deep' do
+      before do
+        stub_const("#{described_class}::MAX_NESTING_LEVELS", 0)
+      end
+
+      let(:hash) do
+        {
+          first: { script: 'my value' },
+          second: { extends: 'first' },
+          test: { extends: 'second' }
+        }
+      end
+
+      it 'raises an error' do
+        expect { subject.extend! }
+          .to raise_error(described_class::NestingTooDeepError)
+      end
+    end
+  end
+end