Bug: printer can print non-parsable value

This fixes a bug where an empty "block" list could be skipped by the printer.

Commit:
ea5b241487c884edb561b12e0a92e947107bbfc1 [ea5b241]
Parents:
ec05b5404b
Author:
Lee Byron <[email protected]>
Date:
5 May 2016 at 7:26:11 AM SGT
Commit Date:
5 May 2016 at 7:26:13 AM SGT

Author: sogko

language/printer/printer.go

@@ -92,11 +92,13 @@ func wrap(start, maybeString, end string) string {
 	}
 	return start + maybeString + end
 }
+
+// Given array, print each item on its own line, wrapped in an indented "{ }" block.
 func block(maybeArray interface{}) string {
-	if maybeArray == nil {
-		return ""
-	}
 	s := toSliceString(maybeArray)
+	if len(s) == 0 {
+		return "{}"
+	}
 	return indent("{\n"+join(s, "\n")) + "\n}"
 }
 

language/printer/schema_printer_test.go

@@ -90,6 +90,8 @@ extend type Foo {
   seven(argument: [String]): Type
 }
 
+type NoFields {}
+
 directive @skip(if: Boolean!) on FIELD | FRAGMENT_SPREAD | INLINE_FRAGMENT
 
 directive @include(if: Boolean!) on FIELD | FRAGMENT_SPREAD | INLINE_FRAGMENT

schema-kitchen-sink.graphql

@@ -37,6 +37,8 @@ extend type Foo {
   seven(argument: [String]): Type
 }
 
+type NoFields {}
+
 directive @skip(if: Boolean!) on FIELD | FRAGMENT_SPREAD | INLINE_FRAGMENT
 
 directive @include(if: Boolean!)