test(fetch_namespace): add initial specs

spec/lib/convenient_service/support/dependency_container/commands/fetch_namespace_spec.rb

@@ -0,0 +1,56 @@
+# frozen_string_literal: true
+
+require "spec_helper"
+
+require "convenient_service"
+
+RSpec.describe ConvenientService::Support::DependencyContainer::Commands::FetchNamespace do
+  example_group "class methods" do
+    describe ".call" do
+      subject(:command_result) { described_class.call(importing_module: importing_module, scope: scope, prepend: prepend) }
+
+      let(:scope) { :class }
+      let(:prepend) { false }
+
+      let(:importing_module) do
+        Class.new do
+          include ConvenientService::Support::DependencyContainer::Import
+        end
+      end
+
+      let(:container) do
+        Module.new do
+          include ConvenientService::Support::DependencyContainer::Export
+
+          export :foo do
+            "foo"
+          end
+
+          export :bar, scope: :class do
+            "bar"
+          end
+        end
+      end
+
+      describe "importing module" do
+        context "when `importing module` imports method" do
+          before do
+            importing_module.import(method, from: container, scope: scope)
+          end
+
+          let(:method) { :bar }
+
+          it "returns valid constant" do
+            expect(command_result).to eq(importing_module::ImportedIncludedClassMethods)
+          end
+        end
+
+        context "when `importing module` does NOT import any method" do
+          it "returns valid constant" do
+            expect(command_result).to eq(importing_module::ImportedIncludedClassMethods)
+          end
+        end
+      end
+    end
+  end
+end