fix(parser): Select the correct AWS CloudFormation resource type base…

…d on similarity (awslabs#183)

* [Fix] Select the correct polymorphic type

cloudformation/resources/awsserverlessapi_definitionuri.go

@@ -1,9 +1,9 @@
 package resources
 
 import (
-	"encoding/json"
+	"sort"
 
-	"reflect"
+	"encoding/json"
 
 	"github.com/mitchellh/mapstructure"
 )
@@ -21,12 +21,15 @@ func (r AWSServerlessApi_DefinitionUri) value() interface{} {
 		return r.String
 	}
 
-	if r.S3Location != nil && !reflect.DeepEqual(r.S3Location, &AWSServerlessApi_S3Location{}) {
-		return r.S3Location
-	}
+	ret := []interface{}{}
 
 	if r.S3Location != nil {
-		return r.S3Location
+		ret = append(ret, *r.S3Location)
+	}
+
+	sort.Sort(byJSONLength(ret))
+	if len(ret) > 0 {
+		return ret[0]
 	}
 
 	return nil

cloudformation/resources/awsserverlessapplication_location.go

@@ -1,9 +1,9 @@
 package resources
 
 import (
-	"encoding/json"
+	"sort"
 
-	"reflect"
+	"encoding/json"
 
 	"github.com/mitchellh/mapstructure"
 )
@@ -21,12 +21,15 @@ func (r AWSServerlessApplication_Location) value() interface{} {
 		return r.String
 	}
 
-	if r.ApplicationLocation != nil && !reflect.DeepEqual(r.ApplicationLocation, &AWSServerlessApplication_ApplicationLocation{}) {
-		return r.ApplicationLocation
-	}
+	ret := []interface{}{}
 
 	if r.ApplicationLocation != nil {
-		return r.ApplicationLocation
+		ret = append(ret, *r.ApplicationLocation)
+	}
+
+	sort.Sort(byJSONLength(ret))
+	if len(ret) > 0 {
+		return ret[0]
 	}
 
 	return nil

cloudformation/resources/awsserverlessfunction_codeuri.go

@@ -1,9 +1,9 @@
 package resources
 
 import (
-	"encoding/json"
+	"sort"
 
-	"reflect"
+	"encoding/json"
 
 	"github.com/mitchellh/mapstructure"
 )
@@ -21,12 +21,15 @@ func (r AWSServerlessFunction_CodeUri) value() interface{} {
 		return r.String
 	}
 
-	if r.S3Location != nil && !reflect.DeepEqual(r.S3Location, &AWSServerlessFunction_S3Location{}) {
-		return r.S3Location
-	}
+	ret := []interface{}{}
 
 	if r.S3Location != nil {
-		return r.S3Location
+		ret = append(ret, *r.S3Location)
+	}
+
+	sort.Sort(byJSONLength(ret))
+	if len(ret) > 0 {
+		return ret[0]
 	}
 
 	return nil

cloudformation/resources/awsserverlessfunction_policies.go

@@ -1,9 +1,9 @@
 package resources
 
 import (
-	"encoding/json"
+	"sort"
 
-	"reflect"
+	"encoding/json"
 
 	"github.com/mitchellh/mapstructure"
 )
@@ -29,12 +29,15 @@ func (r AWSServerlessFunction_Policies) value() interface{} {
 		return r.StringArray
 	}
 
-	if r.IAMPolicyDocument != nil && !reflect.DeepEqual(r.IAMPolicyDocument, &AWSServerlessFunction_IAMPolicyDocument{}) {
-		return r.IAMPolicyDocument
-	}
+	ret := []interface{}{}
 
 	if r.IAMPolicyDocument != nil {
-		return r.IAMPolicyDocument
+		ret = append(ret, *r.IAMPolicyDocument)
+	}
+
+	sort.Sort(byJSONLength(ret))
+	if len(ret) > 0 {
+		return ret[0]
 	}
 
 	if r.IAMPolicyDocumentArray != nil {

cloudformation/resources/awsserverlessfunction_properties.go

@@ -1,9 +1,9 @@
 package resources
 
 import (
-	"encoding/json"
+	"sort"
 
-	"reflect"
+	"encoding/json"
 
 	"github.com/mitchellh/mapstructure"
 )
@@ -24,84 +24,51 @@ type AWSServerlessFunction_Properties struct {
 
 func (r AWSServerlessFunction_Properties) value() interface{} {
 
-	if r.S3Event != nil && !reflect.DeepEqual(r.S3Event, &AWSServerlessFunction_S3Event{}) {
-		return r.S3Event
-	}
-
-	if r.SNSEvent != nil && !reflect.DeepEqual(r.SNSEvent, &AWSServerlessFunction_SNSEvent{}) {
-		return r.SNSEvent
-	}
-
-	if r.SQSEvent != nil && !reflect.DeepEqual(r.SQSEvent, &AWSServerlessFunction_SQSEvent{}) {
-		return r.SQSEvent
-	}
-
-	if r.KinesisEvent != nil && !reflect.DeepEqual(r.KinesisEvent, &AWSServerlessFunction_KinesisEvent{}) {
-		return r.KinesisEvent
-	}
-
-	if r.DynamoDBEvent != nil && !reflect.DeepEqual(r.DynamoDBEvent, &AWSServerlessFunction_DynamoDBEvent{}) {
-		return r.DynamoDBEvent
-	}
-
-	if r.ApiEvent != nil && !reflect.DeepEqual(r.ApiEvent, &AWSServerlessFunction_ApiEvent{}) {
-		return r.ApiEvent
-	}
-
-	if r.ScheduleEvent != nil && !reflect.DeepEqual(r.ScheduleEvent, &AWSServerlessFunction_ScheduleEvent{}) {
-		return r.ScheduleEvent
-	}
-
-	if r.CloudWatchEventEvent != nil && !reflect.DeepEqual(r.CloudWatchEventEvent, &AWSServerlessFunction_CloudWatchEventEvent{}) {
-		return r.CloudWatchEventEvent
-	}
-
-	if r.IoTRuleEvent != nil && !reflect.DeepEqual(r.IoTRuleEvent, &AWSServerlessFunction_IoTRuleEvent{}) {
-		return r.IoTRuleEvent
-	}
-
-	if r.AlexaSkillEvent != nil && !reflect.DeepEqual(r.AlexaSkillEvent, &AWSServerlessFunction_AlexaSkillEvent{}) {
-		return r.AlexaSkillEvent
-	}
+	ret := []interface{}{}
 
 	if r.S3Event != nil {
-		return r.S3Event
+		ret = append(ret, *r.S3Event)
 	}
 
 	if r.SNSEvent != nil {
-		return r.SNSEvent
+		ret = append(ret, *r.SNSEvent)
 	}
 
 	if r.SQSEvent != nil {
-		return r.SQSEvent
+		ret = append(ret, *r.SQSEvent)
 	}
 
 	if r.KinesisEvent != nil {
-		return r.KinesisEvent
+		ret = append(ret, *r.KinesisEvent)
 	}
 
 	if r.DynamoDBEvent != nil {
-		return r.DynamoDBEvent
+		ret = append(ret, *r.DynamoDBEvent)
 	}
 
 	if r.ApiEvent != nil {
-		return r.ApiEvent
+		ret = append(ret, *r.ApiEvent)
 	}
 
 	if r.ScheduleEvent != nil {
-		return r.ScheduleEvent
+		ret = append(ret, *r.ScheduleEvent)
 	}
 
 	if r.CloudWatchEventEvent != nil {
-		return r.CloudWatchEventEvent
+		ret = append(ret, *r.CloudWatchEventEvent)
 	}
 
 	if r.IoTRuleEvent != nil {
-		return r.IoTRuleEvent
+		ret = append(ret, *r.IoTRuleEvent)
 	}
 
 	if r.AlexaSkillEvent != nil {
-		return r.AlexaSkillEvent
+		ret = append(ret, *r.AlexaSkillEvent)
+	}
+
+	sort.Sort(byJSONLength(ret))
+	if len(ret) > 0 {
+		return ret[0]
 	}
 
 	return nil

cloudformation/resources/utils.go

@@ -0,0 +1,36 @@
+package resources
+
+import (
+	"encoding/json"
+)
+
+type byJSONLength []interface{}
+
+func (s byJSONLength) Len() int {
+	return len(s)
+}
+
+func (s byJSONLength) Swap(i, j int) {
+	s[i], s[j] = s[j], s[i]
+}
+
+func (s byJSONLength) Less(i, j int) bool {
+	// Nil is always at the end
+	if s[i] == nil {
+		return false
+	}
+	if s[j] == nil {
+		return true
+	}
+	jsoni, _ := json.Marshal(s[i])
+	jsonj, _ := json.Marshal(s[j])
+
+	if jsoni == nil {
+		return false
+	}
+	if jsonj == nil {
+		return true
+	}
+
+	return len(jsoni) > len(jsonj)
+}

generate/property_test.go

@@ -50,6 +50,43 @@ var _ = Describe("Goformation Code Generator", func() {
 
 	Context("with a polymorphic property", func() {
 
+		Context("with multiple types", func() {
+
+			Context("properly marshals and unmarshals values", func() {
+
+				property := []byte(`{"Properties":{"BatchSize":10,"StartingPosition":"LATEST","Stream":"arn"},"Type":"Kinesis"}`)
+
+				result := &resources.AWSServerlessFunction_EventSource{}
+				err := json.Unmarshal(property, result)
+				output, err2 := json.Marshal(result)
+
+				It("should marshal and unmarhal to same value", func() {
+					Expect(err).To(BeNil())
+					Expect(err2).To(BeNil())
+					Expect(output).To(Equal(property))
+				})
+
+			})
+
+			Context("properly Marshals best value", func() {
+				expected := []byte(`{"BatchSize":10,"Stream":"arn"}`)
+
+				result := &resources.AWSServerlessFunction_Properties{
+					SQSEvent:     &resources.AWSServerlessFunction_SQSEvent{BatchSize: 10},
+					KinesisEvent: &resources.AWSServerlessFunction_KinesisEvent{BatchSize: 10, Stream: "arn"},
+				}
+
+				output, err := result.MarshalJSON()
+
+				It("should marshal and unmarhal to same value", func() {
+					Expect(err).To(BeNil())
+					Expect(output).To(Equal(expected))
+				})
+
+			})
+
+		})
+
 		Context("with a primitive value", func() {
 
 			Context("specified as a Go struct", func() {

generate/templates/polymorphic-property.template

@@ -1,18 +1,17 @@
 package resources
 
 import (
-	"encoding/json"
 	{{ if (.Property.Types) }}
-	"reflect"
+	"sort"
 	{{end}}
+	"encoding/json"
 	{{ if (or .Property.Types .Property.ItemTypes .Property.PrimitiveItemTypes)}}
 	"github.com/mitchellh/mapstructure"
 	{{end}}
 )
 
 // {{.Name}} is a helper struct that can hold either a {{.TypesJoined}} value
 type {{.Name}} struct {
-
 	{{range $type := $.Property.PrimitiveTypes}}
 	{{$type}} *{{convertToGoType $type}}{{end}}
 
@@ -40,15 +39,16 @@ func (r {{.Name}}) value() interface{} {
 		}
 	{{end}}
 
-	{{range $type := $.Property.Types}}
-    		if r.{{$type}} != nil && !reflect.DeepEqual(r.{{$type}}, &{{$.Basename}}_{{$type}}{}) {
-      			return r.{{$type}}
-    		}
-  	{{end}}
-
-	{{range $type := $.Property.Types}}
-		if r.{{$type}} != nil {
-			return r.{{$type}}
+	{{ if (.Property.Types) }}
+		ret := []interface{}{}
+		{{range $type := $.Property.Types}}
+			if r.{{$type}} != nil {
+				ret = append(ret, *r.{{$type}})
+			}
+		{{end}}
+		sort.Sort(byJSONLength(ret))
+		if len(ret) > 0 {
+			return ret[0]
 		}
 	{{end}}