Create initialiser integration test

spec/features/initialiser_spec.rb

@@ -0,0 +1,87 @@
+RSpec.describe "Initialising Kangaru in a target gem", :with_gem do
+  subject(:require_gem) { gem.load! }
+
+  before do
+    gem.gem_file("foobar").write(<<~RUBY)
+      module SomeGem
+        class Foobar
+        end
+      end
+    RUBY
+  end
+
+  context "when the target gem does not extend the initialiser" do
+    before do
+      gem.main_file.write(<<~RUBY)
+        require "kangaru"
+
+        module SomeGem
+        end
+      RUBY
+    end
+
+    it "loads the gem module" do
+      expect { require_gem }
+        .to change { Object.const_defined?(:SomeGem) }
+        .from(false)
+        .to(true)
+    end
+
+    it "does not autoload gem files" do
+      expect { require_gem }
+        .not_to change { Object.const_defined?("SomeGem::Foobar") }
+        .from(false)
+    end
+
+    it "does not set the Kangaru application reference" do
+      expect { require_gem }.not_to change { Kangaru.application }.from(nil)
+    end
+  end
+
+  context "when the target gem extends the initialiser" do
+    before do
+      gem.main_file.write(<<~RUBY)
+        require "kangaru"
+
+        module SomeGem
+          extend Kangaru::Initialiser
+        end
+      RUBY
+    end
+
+    it "loads the gem module" do
+      expect { require_gem }
+        .to change { Object.const_defined?("SomeGem") }
+        .from(false)
+        .to(true)
+    end
+
+    it "autoloads gem files" do
+      expect { require_gem }
+        .to change { Object.const_defined?("SomeGem::Foobar") }
+        .from(false)
+        .to(true)
+    end
+
+    it "sets the Kangaru application reference" do
+      expect { require_gem }
+        .to change { Kangaru.application }
+        .from(nil)
+        .to(a_kind_of(Kangaru::Application))
+    end
+
+    describe "application reference" do
+      subject(:application) { Kangaru.application }
+
+      before { require_gem }
+
+      it "sets the application root dir to the gem lib path" do
+        expect(application.root_dir).to eq(gem.lib_path)
+      end
+
+      it "sets the application root file to the main gem file" do
+        expect(application.root_file).to eq(gem.main_file)
+      end
+    end
+  end
+end

spec/kangaru/testing/gem_spec.rb

@@ -79,6 +79,10 @@
   describe "#load!" do
     subject(:load!) { gem.load! }
 
+    after do
+      Object.send(:remove_const, :SomeGem) if Object.const_defined?(:SomeGem)
+    end
+
     context "when gem has not been created" do
       it "raises an error" do
         expect { load! }.to raise_error(