1 files changed, 147 insertions, 0 deletions
diff --git a/spec/lib/declarative_enum_spec.rb b/spec/lib/declarative_enum_spec.rb
new file mode 100644
index 00000000000..66cda9fc3a8
--- /dev/null
+++ b/spec/lib/declarative_enum_spec.rb
@@ -0,0 +1,147 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe DeclarativeEnum do
+  let(:enum_module) do
+    Module.new do
+      extend DeclarativeEnum
+
+      key :my_enum
+      name 'MyEnumName'
+
+      description "Enum description"
+
+      define do
+        foo value: 0, description: 'description of foo'
+        bar value: 1, description: 'description of bar'
+      end
+    end
+  end
+
+  let(:original_definition) do
+    {
+      foo: { description: 'description of foo', value: 0 },
+      bar: { description: 'description of bar', value: 1 }
+    }
+  end
+
+  describe '.key' do
+    subject(:key) { enum_module.key(new_key) }
+
+    context 'when the argument is set' do
+      let(:new_key) { :new_enum_key }
+
+      it 'changes the key' do
+        expect { key }.to change { enum_module.key }.from(:my_enum).to(:new_enum_key)
+      end
+    end
+
+    context 'when the argument is `nil`' do
+      let(:new_key) { nil }
+
+      it { is_expected.to eq(:my_enum) }
+    end
+  end
+
+  describe '.name' do
+    subject(:name) { enum_module.name(new_name) }
+
+    context 'when the argument is set' do
+      let(:new_name) { 'NewMyEnumName' }
+
+      it 'changes the name' do
+        expect { name }.to change { enum_module.name }.from('MyEnumName').to('NewMyEnumName')
+      end
+    end
+
+    context 'when the argument is `nil`' do
+      let(:new_name) { nil }
+
+      it { is_expected.to eq('MyEnumName') }
+    end
+  end
+
+  describe '.description' do
+    subject(:description) { enum_module.description(new_description) }
+
+    context 'when the argument is set' do
+      let(:new_description) { 'New enum description' }
+
+      it 'changes the description' do
+        expect { description }.to change { enum_module.description }.from('Enum description').to('New enum description')
+      end
+    end
+
+    context 'when the argument is `nil`' do
+      let(:new_description) { nil }
+
+      it { is_expected.to eq('Enum description') }
+    end
+  end
+
+  describe '.define' do
+    subject(:define) { enum_module.define(&block) }
+
+    context 'when there is a block given' do
+      context 'when the given block tries to register the same key' do
+        let(:block) do
+          proc do
+            foo value: 2, description: 'description of foo'
+          end
+        end
+
+        it 'raises a `KeyCollisionError`' do
+          expect { define }.to raise_error(DeclarativeEnum::Builder::KeyCollisionError)
+        end
+      end
+
+      context 'when the given block does not try to register the same key' do
+        let(:expected_new_definition) { original_definition.merge(zoo: { description: 'description of zoo', value: 0 }) }
+        let(:block) do
+          proc do
+            zoo value: 0, description: 'description of zoo'
+          end
+        end
+
+        it 'appends the new definition' do
+          expect { define }.to change { enum_module.definition }.from(original_definition).to(expected_new_definition)
+        end
+      end
+    end
+
+    context 'when there is no block given' do
+      let(:block) { nil }
+
+      it 'raises a LocalJumpError' do
+        expect { define }.to raise_error(LocalJumpError)
+      end
+    end
+  end
+
+  describe '.definition' do
+    subject { enum_module.definition }
+
+    it { is_expected.to eq(original_definition) }
+  end
+
+  describe 'extending the enum module' do
+    let(:extended_definition) { original_definition.merge(zoo: { value: 2, description: 'description of zoo' }) }
+    let(:new_enum_module) do
+      Module.new do
+        extend DeclarativeEnum
+
+        define do
+          zoo value: 2, description: 'description of zoo'
+        end
+      end
+    end
+
+    subject(:prepend_new_enum_module) { enum_module.prepend(new_enum_module) }
+
+    it 'extends the values of the base enum module' do
+      expect { prepend_new_enum_module }.to change { enum_module.definition }.from(original_definition)
+                                                                             .to(extended_definition)
+    end
+  end
+end