Fix issues with resolver implementation resolution

codegen/build.go

@@ -125,6 +125,11 @@ func (cfg *Config) bind() (*Build, error) {
 	namedTypes := cfg.buildNamedTypes()
 
 	progLoader := newLoader(namedTypes, true)
+	for _, i := range cfg.Directives.Implementations() {
+		pkg, _ := pkgAndType(i)
+		progLoader.Import(pkg)
+	}
+
 	prog, err := progLoader.Load()
 	if err != nil {
 		return nil, errors.Wrap(err, "loading failed")

codegen/codegen.go

@@ -11,6 +11,7 @@ import (
 	"github.com/pkg/errors"
 	"github.com/vektah/gqlparser"
 	"github.com/vektah/gqlparser/ast"
+	"github.com/vektah/gqlparser/gqlerror"
 )
 
 func Generate(cfg Config) error {
@@ -160,9 +161,10 @@ func (cfg *Config) normalize() error {
 	}
 	srcs = append(srcs, pluginSrcs...)
 
-	cfg.schema, err = gqlparser.LoadSchema(srcs...)
-	if err != nil {
-		return err
+	var gqlerr *gqlerror.Error
+	cfg.schema, gqlerr = gqlparser.LoadSchema(srcs...)
+	if gqlerr != nil {
+		return gqlerr
 	}
 	return nil
 }

codegen/config.go

@@ -177,6 +177,16 @@ func (dm DirectiveMap) ImplementationFor(name string) string {
 	return d.Implementation
 }
 
+func (dm DirectiveMap) Implementations() []string {
+	impls := []string{}
+	for _, d := range dm {
+		if d.Implementation != "" {
+			impls = append(impls, d.Implementation)
+		}
+	}
+	return impls
+}
+
 // findCfg searches for the config file in this directory and all parents up the tree
 // looking for the closest match
 func findCfg() (string, error) {

codegen/plugin.go

@@ -1,27 +1,32 @@
 package codegen
 
-import "github.com/vektah/gqlparser/ast"
+import (
+	"github.com/vektah/gqlparser/ast"
+)
 
 type Plugin interface {
 	Execute(c *Config, schema *ast.Schema) error
 	Schema(cfg *Config) (*ast.Source, error)
 }
 
-type PluginRegistry []Plugin
+type PluginRegistry struct {
+	plugins []Plugin
+}
 
 var DefaultPluginRegistry = PluginRegistry{}
 
 // RegisterPlugin registers a plugin in the default plugin register
 func RegisterPlugin(p Plugin) {
+
 	DefaultPluginRegistry.Register(p)
 }
 
-func (r PluginRegistry) Register(p Plugin) {
-	r = append(r, p)
+func (r *PluginRegistry) Register(p Plugin) {
+	r.plugins = append(r.plugins, p)
 }
 
-func (r PluginRegistry) Schemas(c *Config) (srcs []*ast.Source, err error) {
-	for _, p := range r {
+func (r *PluginRegistry) Schemas(c *Config) (srcs []*ast.Source, err error) {
+	for _, p := range r.plugins {
 		src, err := p.Schema(c)
 		if err != nil {
 			return nil, err
@@ -33,8 +38,8 @@ func (r PluginRegistry) Schemas(c *Config) (srcs []*ast.Source, err error) {
 	return srcs, err
 }
 
-func (r PluginRegistry) Execute(cfg *Config, schema *ast.Schema) error {
-	for _, p := range r {
+func (r *PluginRegistry) Execute(cfg *Config, schema *ast.Schema) error {
+	for _, p := range r.plugins {
 		if err := p.Execute(cfg, schema); err != nil {
 			return err
 		}

codegen/plugins/resolver/plugin.go

@@ -31,6 +31,12 @@ func (p *Plugin) Execute(cfg *codegen.Config, schema *ast.Schema) error {
 				if _, ok := cfg.Models[typ.Name]; !ok {
 					cfg.Models[typ.Name] = codegen.TypeMapEntry{}
 				}
+				if cfg.Models[typ.Name].Fields == nil {
+					cfg.Models[typ.Name] = codegen.TypeMapEntry{
+						Model:  typ.Name,
+						Fields: make(map[string]codegen.TypeMapField),
+					}
+				}
 				if tmf, ok := cfg.Models[typ.Name].Fields[f.Name]; ok {
 					cfg.Models[typ.Name].Fields[f.Name] = codegen.TypeMapField{
 						ForceResolver: true,

codegen/testserver/gqlgen.yml

@@ -27,8 +27,6 @@ models:
     model: "github.com/99designs/gqlgen/codegen/testserver.Rectangle"
   ForcedResolver:
     model: "github.com/99designs/gqlgen/codegen/testserver.ForcedResolver"
-    fields:
-      field: { resolver: true }
   Error:
     model: "github.com/99designs/gqlgen/codegen/testserver.Error"
 

codegen/testserver/schema.graphql

@@ -129,7 +129,7 @@ type Rectangle implements Shape {
 union ShapeUnion = Circle | Rectangle
 
 type ForcedResolver {
-    field: Circle
+    field: Circle @resolver
 }
 
 input ComplexInput {