added cleaner to prevent null values from being output (#81)

* added cleaner to prevent null values from being output

* updated api test case

pkg/plugins/api/api_test.go

@@ -69,18 +69,29 @@ func TestRegisterParser(t *testing.T) {
 				transform types.TemplateObject,
 				errors []error,
 			) {
-				resources = types.TemplateObject{
+				resources = make(types.TemplateObject)
+
+				resources[name] = types.TemplateObject{
 					"Name": name,
 					"Data": data,
 				}
 
 				return
 			},
 			output: apiTypes.PluginParserResult{
+				Conditions: types.TemplateObject{},
+				Metadata:   types.TemplateObject{},
+				Mappings:   types.TemplateObject{},
+				Outputs:    types.TemplateObject{},
+				Parameters: types.TemplateObject{},
 				Resources: types.TemplateObject{
-					"Name": "TestName",
-					"Data": "TestData",
+					"TestName": map[string]interface{}{
+						"Name": "TestName",
+						"Data": "TestData",
+					},
 				},
+				Transform: types.TemplateObject{},
+				Errors:    []error(nil),
 			},
 		},
 	}
@@ -101,6 +112,6 @@ func TestRegisterParser(t *testing.T) {
 			t.Error(err)
 		}
 
-		assert.Equal(pluginResult, test.output, fmt.Sprintf("Test %d", i))
+		assert.Equal(test.output, pluginResult, fmt.Sprintf("Test %d", i))
 	}
 }

pkg/plugins/api/marshalling.go

@@ -3,6 +3,8 @@ package api
 import (
 	"log"
 
+	"github.com/KablamoOSS/yaml"
+
 	pluginTypes "github.com/KablamoOSS/kombustion/pkg/plugins/api/types"
 	kombustionTypes "github.com/KablamoOSS/kombustion/types"
 
@@ -26,16 +28,16 @@ func marshallParserResult(
 	resources kombustionTypes.TemplateObject,
 	transform kombustionTypes.TemplateObject,
 	errors []error,
-
 ) (blob []byte) {
+
 	result := pluginTypes.PluginParserResult{
-		Conditions: conditions,
-		Metadata:   metadata,
-		Mappings:   mappings,
-		Outputs:    outputs,
-		Parameters: parameters,
-		Resources:  resources,
-		Transform:  transform,
+		Conditions: cleanResult(conditions),
+		Metadata:   cleanResult(metadata),
+		Mappings:   cleanResult(mappings),
+		Outputs:    cleanResult(outputs),
+		Parameters: cleanResult(parameters),
+		Resources:  cleanResult(resources),
+		Transform:  cleanResult(transform),
 		Errors:     errors,
 	}
 	blob, err := msgpack.Marshal(&result)
@@ -44,3 +46,24 @@ func marshallParserResult(
 	}
 	return
 }
+
+// Clean the templateObject by parsing to YAML and back
+// This needs to happen before being marshalled to binary (msgpack)
+// because the tags on the struct's are not stored in msgpack,
+// therefore the omitempty directive is lost
+//
+// This prevents null values being output
+func cleanResult(objects kombustionTypes.TemplateObject) (result kombustionTypes.TemplateObject) {
+	result = make(kombustionTypes.TemplateObject)
+
+	for k, v := range objects {
+		if obj, err := yaml.Marshal(v); err == nil {
+			var tempObject kombustionTypes.TemplateObject
+			if err = yaml.Unmarshal(obj, &tempObject); err == nil {
+				result[k] = tempObject
+			}
+		}
+	}
+
+	return
+}