Added a new stub for attempting to delete a missing asset

This is needed for testing how publishing applications react to attempting to delete a missing asset. At the moment they are not handling not found errors, meaning that the state of the publishing application remains out of sync with asset manager and causing other logical issues.

This commit also adds some test coverage for other asset deletion stubs and makes byebug available in the testing runtime.

lib/gds_api/test_helpers/asset_manager.rb

@@ -92,6 +92,11 @@ def stub_asset_manager_delete_asset(asset_id, body = {})
           .to_return(body: body.to_json, status: 200)
       end
 
+      def stub_asset_manager_delete_asset_missing(asset_id)
+        stub_request(:delete, "#{ASSET_MANAGER_ENDPOINT}/assets/#{asset_id}")
+          .to_return(status: 404)
+      end
+
       def stub_asset_manager_delete_asset_failure(asset_id)
         stub_request(:delete, "#{ASSET_MANAGER_ENDPOINT}/assets/#{asset_id}").to_return(status: 500)
       end

test/test_helpers/asset_manager_test.rb

@@ -64,4 +64,39 @@
       end
     end
   end
+
+  describe "#stub_asset_manager_delete_asset" do
+    it "returns an ok response and the provided body" do
+      asset_id = "some-asset-id"
+      body = { key: "value" }
+      stub_asset_manager_delete_asset(asset_id, body)
+
+      response = stub_asset_manager.delete_asset(asset_id)
+
+      assert_equal 200, response.code
+      assert_equal body[:key], response["key"]
+    end
+  end
+
+  describe "#stub_asset_manager_delete_asset_missing" do
+    it "raises a not found error" do
+      asset_id = "some-asset-id"
+      stub_asset_manager_delete_asset_missing(asset_id)
+
+      assert_raises GdsApi::HTTPNotFound do
+        stub_asset_manager.delete_asset(asset_id)
+      end
+    end
+  end
+
+  describe "#stub_asset_manager_delete_asset_failure" do
+    it "raises an internal server error" do
+      asset_id = "some-asset-id"
+      stub_asset_manager_delete_asset_failure(asset_id)
+
+      assert_raises GdsApi::HTTPInternalServerError do
+        stub_asset_manager.delete_asset(asset_id)
+      end
+    end
+  end
 end