feat(schema): Improve cloudformation If to accept structs (awslabs#368)

cloudformation/intrinsics.go

@@ -2,6 +2,7 @@ package cloudformation
 
 import (
 	"encoding/base64"
+	"encoding/json"
 	"fmt"
 	"strings"
 
@@ -180,8 +181,19 @@ func FindInMap(mapName, topLevelKey, secondLevelKey interface{}) string {
 }
 
 // If returns one value if the specified condition evaluates to true and another value if the specified condition evaluates to false. Currently, AWS CloudFormation supports the Fn::If intrinsic function in the metadata attribute, update policy attribute, and property values in the Resources section and Outputs sections of a template. You can use the AWS::NoValue pseudo parameter as a return value to remove the corresponding property.
-func If(value, ifEqual, ifNotEqual interface{}) string {
-	return encode(fmt.Sprintf(`{ "Fn::If" : [ %q, %q, %q ] }`, value, ifEqual, ifNotEqual))
+func If(value, ifEqual interface{}, ifNotEqual interface{}) string {
+
+	equal, err := json.Marshal(ifEqual)
+	if err != nil {
+		panic(err)
+	}
+
+	notEqual, err := json.Marshal(ifNotEqual)
+	if err != nil {
+		panic(err)
+	}
+
+	return encode(fmt.Sprintf(`{ "Fn::If" : [ %q, %v, %v ] }`, value, string(equal), string(notEqual)))
 }
 
 // (str, []str) -> str