Merge pull request #588 from 99designs/fix-default-scalar-implementat…

…ion-regression

Fix default scalar implementation regression

codegen/testserver/resolver.go

@@ -116,6 +116,9 @@ func (r *queryResolver) DeprecatedField(ctx context.Context) (string, error) {
 func (r *queryResolver) Panics(ctx context.Context) (*Panics, error) {
 	panic("not implemented")
 }
+func (r *queryResolver) DefaultScalar(ctx context.Context, arg string) (string, error) {
+	panic("not implemented")
+}
 func (r *queryResolver) ValidType(ctx context.Context) (*ValidType, error) {
 	panic("not implemented")
 }

codegen/testserver/scalar_default.graphql

@@ -0,0 +1,6 @@
+extend type Query {
+    defaultScalar(arg: DefaultScalarImplementation! = "default"): DefaultScalarImplementation!
+}
+
+""" This doesnt have an implementation in the typemap, so it should act like a string """
+scalar DefaultScalarImplementation

codegen/testserver/scalar_default_test.go

@@ -0,0 +1,34 @@
+package testserver
+
+import (
+	"context"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/99designs/gqlgen/client"
+	"github.com/99designs/gqlgen/handler"
+	"github.com/stretchr/testify/require"
+)
+
+func TestDefaultScalarImplementation(t *testing.T) {
+	resolvers := &Stub{}
+
+	srv := httptest.NewServer(handler.GraphQL(NewExecutableSchema(Config{Resolvers: resolvers})))
+	c := client.New(srv.URL)
+
+	resolvers.QueryResolver.DefaultScalar = func(ctx context.Context, arg string) (i string, e error) {
+		return arg, nil
+	}
+
+	t.Run("with arg value", func(t *testing.T) {
+		var resp struct{ DefaultScalar string }
+		c.MustPost(`query { defaultScalar(arg: "fff") }`, &resp)
+		require.Equal(t, "fff", resp.DefaultScalar)
+	})
+
+	t.Run("with default value", func(t *testing.T) {
+		var resp struct{ DefaultScalar string }
+		c.MustPost(`query { defaultScalar  }`, &resp)
+		require.Equal(t, "default", resp.DefaultScalar)
+	})
+}

plugin/modelgen/models.go

@@ -4,10 +4,9 @@ import (
 	"go/types"
 	"sort"
 
-	"github.com/99designs/gqlgen/internal/code"
-
 	"github.com/99designs/gqlgen/codegen/config"
 	"github.com/99designs/gqlgen/codegen/templates"
+	"github.com/99designs/gqlgen/internal/code"
 	"github.com/99designs/gqlgen/plugin"
 	"github.com/vektah/gqlparser/ast"
 )
@@ -17,6 +16,7 @@ type ModelBuild struct {
 	Interfaces  []*Interface
 	Models      []*Object
 	Enums       []*Enum
+	Scalars     []string
 }
 
 type Interface struct {
@@ -159,6 +159,8 @@ func (m *Plugin) MutateConfig(cfg *config.Config) error {
 			}
 
 			b.Enums = append(b.Enums, it)
+		case ast.Scalar:
+			b.Scalars = append(b.Scalars, schemaType.Name)
 		}
 	}
 
@@ -175,6 +177,9 @@ func (m *Plugin) MutateConfig(cfg *config.Config) error {
 	for _, it := range b.Interfaces {
 		cfg.Models.Add(it.Name, cfg.Model.ImportPath()+"."+it.Name)
 	}
+	for _, it := range b.Scalars {
+		cfg.Models.Add(it, "github.com/99designs/gqlgen/graphql.String")
+	}
 
 	if len(b.Models) == 0 && len(b.Enums) == 0 {
 		return nil