Maps as changesets

codegen/config/binder.go

@@ -204,6 +204,13 @@ func (t *TypeReference) IsPtr() bool {
 	return isPtr
 }
 
+func (t *TypeReference) IsNilable() bool {
+	_, isPtr := t.GO.(*types.Pointer)
+	_, isMap := t.GO.(*types.Map)
+	_, isInterface := t.GO.(*types.Interface)
+	return isPtr || isMap || isInterface
+}
+
 func (t *TypeReference) IsSlice() bool {
 	_, isSlice := t.GO.(*types.Slice)
 	return isSlice

codegen/field.go

@@ -102,6 +102,7 @@ func (b *builder) bindField(obj *Object, f *Field) error {
 		f.IsResolver = true
 		return nil
 	case obj.Type == config.MapType:
+		f.GoFieldType = GoFieldMap
 		return nil
 	case b.Config.Models[obj.Name].Fields[f.Name].FieldName != "":
 		f.GoFieldName = b.Config.Models[obj.Name].Fields[f.Name].FieldName
@@ -298,6 +299,10 @@ func (f *Field) IsVariable() bool {
 	return f.GoFieldType == GoFieldVariable
 }
 
+func (f *Field) IsMap() bool {
+	return f.GoFieldType == GoFieldMap
+}
+
 func (f *Field) IsConcurrent() bool {
 	if f.Object.DisableConcurrency {
 		return false

codegen/field.gotpl

@@ -37,7 +37,7 @@
 		}
 	}
 {{ else }}
-	func (ec *executionContext) _{{$object.Name}}_{{$field.Name}}(ctx context.Context, field graphql.CollectedField{{ if not $object.Root }}, obj *{{$object.Type | ref}}{{end}}) graphql.Marshaler {
+	func (ec *executionContext) _{{$object.Name}}_{{$field.Name}}(ctx context.Context, field graphql.CollectedField{{ if not $object.Root }}, obj {{$object.Reference | ref}}{{end}}) graphql.Marshaler {
 		ctx = ec.Tracer.StartFieldExecution(ctx, field)
 		defer func () { ec.Tracer.EndFieldExecution(ctx) }()
 		rctx := &graphql.ResolverContext{
@@ -60,6 +60,17 @@
 			ctx = rctx  // use context from middleware stack in children
 			{{- if $field.IsResolver }}
 				return ec.resolvers.{{ $field.ShortInvocation }}
+			{{- else if $field.IsMap }}
+				switch v := {{$field.GoReceiverName}}[{{$field.Name|quote}}].(type) {
+				case {{$field.TypeReference.GO | ref}}:
+					return v, nil
+				case {{$field.TypeReference.Elem.GO | ref}}:
+					return &v, nil
+				case nil:
+					return ({{$field.TypeReference.GO | ref}})(nil), nil
+				default:
+					return nil, fmt.Errorf("unexpected type %T for field %s", v, {{ $field.Name | quote}})
+				}
 			{{- else if $field.IsMethod }}
 				{{- if $field.NoErr }}
 					return {{$field.GoReceiverName}}.{{$field.GoFieldName}}({{ $field.CallArgs }}), nil

codegen/object.go

@@ -17,6 +17,7 @@ const (
 	GoFieldUndefined GoFieldType = iota
 	GoFieldMethod
 	GoFieldVariable
+	GoFieldMap
 )
 
 type Object struct {
@@ -80,6 +81,15 @@ func (b *builder) buildObject(typ *ast.Definition) (*Object, error) {
 	return obj, nil
 }
 
+func (o *Object) Reference() types.Type {
+	switch o.Type.(type) {
+	case *types.Pointer, *types.Slice, *types.Map:
+		return o.Type
+	}
+
+	return types.NewPointer(o.Type)
+}
+
 type Objects []*Object
 
 func (o *Object) Implementors() string {

codegen/object.gotpl

@@ -23,7 +23,7 @@ func (ec *executionContext) _{{$object.Name}}(ctx context.Context, sel ast.Selec
 	}
 }
 {{- else }}
-func (ec *executionContext) _{{$object.Name}}(ctx context.Context, sel ast.SelectionSet{{ if not $object.Root }},obj *{{$object.Type | ref }}{{ end }}) graphql.Marshaler {
+func (ec *executionContext) _{{$object.Name}}(ctx context.Context, sel ast.SelectionSet{{ if not $object.Root }},obj {{$object.Reference | ref }}{{ end }}) graphql.Marshaler {
 	fields := graphql.CollectFields(ctx, sel, {{$object.Name|lcFirst}}Implementors)
 	{{if $object.Root}}
 		ctx = graphql.WithResolverContext(ctx, &graphql.ResolverContext{

codegen/testdata/schema.graphql

@@ -1,7 +1,6 @@
 type Query {
     invalidIdentifier: InvalidIdentifier
     collision: It
-    mapInput(input: Changes): Boolean
     recursive(input: RecursiveInputSlice): Boolean
     nestedInputs(input: [[OuterInput]] = [[{inner: {id: 1}}]]): Boolean
     nestedOutputs: [[OuterObject]]
@@ -49,11 +48,6 @@ type It {
     id: ID!
 }
 
-input Changes {
-    a: Int
-    b: Int
-}
-
 input RecursiveInputSlice {
     self: [RecursiveInputSlice!]
 }