WIP: remove toJson helper – not sure I like this...

lib/src/json_serializable_generator.dart

@@ -166,7 +166,7 @@ class JsonSerializableGenerator
 
         // If `fieldName` collides with one of the local helpers, prefix
         // access with `this.`.
-        if (fieldName == toJsonMapVarName || fieldName == toJsonMapHelperName) {
+        if (fieldName == toJsonMapVarName) {
           fieldName = 'this.$fieldName';
         }
 
@@ -184,18 +184,14 @@ class JsonSerializableGenerator
             buffer.writeln('};');
             buffer.writeln();
 
-            // write the helper to be used by all following null-excluding
-            // fields
-            buffer.writeln('''
-void $toJsonMapHelperName(String key, dynamic value) {
-  if (value != null) {
-    $toJsonMapVarName[key] = value;
-  }
-}''');
             directWrite = false;
           }
-          buffer.writeln('$toJsonMapHelperName($safeJsonKeyString, '
-              '${_serialize(field.type, fieldName, _nullable(field))});');
+          buffer.writeln('''if ($fieldName != null) { 
+  $toJsonMapVarName[$safeJsonKeyString] = ${_serialize(field.type, fieldName, _nullable(field))};
+}''');
+
+          //$toJsonMapHelperName($safeJsonKeyString, '
+          //'${_serialize(field.type, fieldName, _nullable(field))});');
         }
       } on UnsupportedTypeError {
         throw new InvalidGenerationSourceError(

lib/src/utils.dart

@@ -45,4 +45,3 @@ void log(object) {
 }
 
 final toJsonMapVarName = 'val';
-final toJsonMapHelperName = 'writeNotNull';

test/json_serializable_test.dart

@@ -199,13 +199,11 @@ abstract class _$OrderSerializerMixin {
     test('some', () async {
       var output = await _runForElementNamed('IncludeIfNullAll');
       expect(output, isNot(contains(toJsonMapVarName)));
-      expect(output, isNot(contains(toJsonMapHelperName)));
     });
 
     test('all', () async {
       var output = await _runForElementNamed('IncludeIfNullOverride');
       expect(output, contains("'number': number,"));
-      expect(output, contains("$toJsonMapHelperName('str', str);"));
     });
   });
 }

test/kitchen_sink_test.dart

@@ -190,6 +190,5 @@ final _expectedOrder = [
   'stringDateTimeMap',
   'crazyComplex',
   toJsonMapVarName,
-  toJsonMapHelperName,
   r'$string'
 ];

test/test_files/bathtub.dart

@@ -84,8 +84,6 @@ class Bathtub extends Object
   // Handle fields with names that collide with helper names
   @JsonKey(nullable: false, includeIfNull: false)
   Map<String, bool> val = {};
-  @JsonKey(nullable: false)
-  bool writeNotNull;
   @JsonKey(nullable: false, name: r'$string')
   String string;
 

test/test_files/kitchen_sink.dart

@@ -74,7 +74,6 @@ class KitchenSink extends Object with _$KitchenSinkSerializerMixin {
   // Handle fields with names that collide with helper names
   @JsonKey(includeIfNull: false)
   Map<String, bool> val;
-  bool writeNotNull;
   @JsonKey(name: r'$string')
   String string;