Add fully customizable resolver errors

.gitattributes

@@ -1,2 +1,3 @@
 /codegen/templates/data.go linguist-generated
 /example/dataloader/*_gen.go linguist-generated
+generated.go linguist-generated

README.md

@@ -25,3 +25,4 @@ See the [docs](https://gqlgen.com/) for a getting started guide.
 | Hooks for error logging | :+1: | :no_entry: | :no_entry: | :no_entry: |
 | Dataloading | :+1: | :+1: | :no_entry: | :warning: |
 | Concurrency | :+1: | :+1: | :no_entry: [pr](https://github.com/graphql-go/graphql/pull/132) | :+1: |
+| Custom errors & error.path | :+1: | :no_entry: [is](https://github.com/graphql-go/graphql/issues/259) | :no_entry: | :no_entry: |

client/client.go

@@ -9,7 +9,6 @@ import (
 	"net/http"
 
 	"github.com/mitchellh/mapstructure"
-	"github.com/vektah/gqlgen/neelance/errors"
 )
 
 // Client for graphql requests
@@ -101,23 +100,28 @@ func (p *Client) Post(query string, response interface{}, options ...Option) err
 
 	// decode it into map string first, let mapstructure do the final decode
 	// because it can be much stricter about unknown fields.
-	respDataRaw := map[string]interface{}{}
+	respDataRaw := struct {
+		Data   interface{}
+		Errors json.RawMessage
+	}{}
 	err = json.Unmarshal(responseBody, &respDataRaw)
 	if err != nil {
 		return fmt.Errorf("decode: %s", err.Error())
 	}
 
-	if respDataRaw["errors"] != nil {
-		var errs []*errors.QueryError
-		if err := unpack(respDataRaw["errors"], &errs); err != nil {
-			return err
-		}
-		if len(errs) > 0 {
-			return fmt.Errorf("errors: %s", errs)
-		}
+	if respDataRaw.Errors != nil {
+		return RawJsonError{respDataRaw.Errors}
 	}
 
-	return unpack(respDataRaw["data"], response)
+	return unpack(respDataRaw.Data, response)
+}
+
+type RawJsonError struct {
+	json.RawMessage
+}
+
+func (r RawJsonError) Error() string {
+	return string(r.RawMessage)
 }
 
 func unpack(data interface{}, into interface{}) error {

codegen/codegen.go

@@ -168,7 +168,7 @@ func write(filename string, b []byte) error {
 
 	formatted, err := gofmt(filename, b)
 	if err != nil {
-		fmt.Fprintf(os.Stderr, "gofmt failed: %s", err.Error())
+		fmt.Fprintf(os.Stderr, "gofmt failed: %s\n", err.Error())
 		formatted = b
 	}
 

codegen/object.go

@@ -82,7 +82,7 @@ func (f *Field) CallArgs() string {
 	var args []string
 
 	if f.GoMethodName == "" {
-		args = append(args, "rctx")
+		args = append(args, "ctx")
 
 		if !f.Object.Root {
 			args = append(args, "obj")
@@ -115,7 +115,12 @@ func (f *Field) doWriteJson(val string, remainingMods []string, isPtr bool, dept
 
 		return tpl(`{{.arr}} := graphql.Array{}
 			for {{.index}} := range {{.val}} {
-				{{.arr}} = append({{.arr}}, func() graphql.Marshaler { {{ .next }} }())
+				{{.arr}} = append({{.arr}}, func() graphql.Marshaler {
+					rctx := graphql.GetResolverContext(ctx)
+					rctx.PushIndex({{.index}})
+					defer rctx.Pop()
+					{{ .next }} 
+				}())
 			}
 			return {{.arr}}`, map[string]interface{}{
 			"val":   val,

codegen/templates/args.gotpl

@@ -5,7 +5,7 @@
 			var err error
 			{{$arg.Unmarshal (print "arg" $i) "tmp" }}
 			if err != nil {
-				ec.Error(err)
+				ec.Error(ctx, err)
 				{{- if $arg.Object.Stream }}
 					return nil
 				{{- else }}
@@ -17,7 +17,7 @@
 			var err error
 			{{$arg.Unmarshal (print "arg" $i) "tmp" }}
 			if err != nil {
-				ec.Error(err)
+				ec.Error(ctx, err)
 				{{- if $arg.Object.Stream }}
 					return nil
 				{{- else }}

codegen/templates/field.gotpl

@@ -4,10 +4,10 @@
 {{- if $object.Stream }}
 	func (ec *executionContext) _{{$object.GQLType}}_{{$field.GQLName}}(ctx context.Context, field graphql.CollectedField) func() graphql.Marshaler {
 		{{- template "args.gotpl" $field.Args }}
-		rctx := graphql.WithResolverContext(ctx, &graphql.ResolverContext{Field: field})
+		ctx = graphql.WithResolverContext(ctx, &graphql.ResolverContext{Field: field})
 		results, err := ec.resolvers.{{ $object.GQLType }}_{{ $field.GQLName }}({{ $field.CallArgs }})
 		if err != nil {
-			ec.Error(err)
+			ec.Error(ctx, err)
 			return nil
 		}
 		return func() graphql.Marshaler {
@@ -25,14 +25,26 @@
 		{{- template "args.gotpl" $field.Args }}
 
 		{{- if $field.IsConcurrent }}
+			ctx = graphql.WithResolverContext(ctx, &graphql.ResolverContext{
+				Object: {{$object.GQLType|quote}},
+				Args: {{if $field.Args }}args{{else}}nil{{end}},
+				Field: field,
+			})
 			return graphql.Defer(func() (ret graphql.Marshaler) {
 				defer func() {
 					if r := recover(); r != nil {
 						userErr := ec.Recover(ctx, r)
-						ec.Error(userErr)
+						ec.Error(ctx, userErr)
 						ret = graphql.Null
 					}
 				}()
+		{{ else }}
+			rctx := graphql.GetResolverContext(ctx)
+			rctx.Object = {{$object.GQLType|quote}}
+			rctx.Args = {{if $field.Args }}args{{else}}nil{{end}}
+			rctx.Field = field
+			rctx.PushField(field.Alias)
+			defer rctx.Pop()
 		{{- end }}
 
 			{{- if $field.GoVarName }}
@@ -43,21 +55,17 @@
 				{{- else }}
 					res, err := {{$field.GoMethodName}}({{ $field.CallArgs }})
 					if err != nil {
-						ec.Error(err)
+						ec.Error(ctx, err)
 						return graphql.Null
 					}
 				{{- end }}
 			{{- else }}
-				rctx := graphql.WithResolverContext(ctx, &graphql.ResolverContext{
-					Object: {{$object.GQLType|quote}},
-					Args: {{if $field.Args }}args{{else}}nil{{end}},
-					Field: field,
-				})
-				resTmp, err := ec.ResolverMiddleware(rctx, func(rctx context.Context) (interface{}, error) {
+
+				resTmp, err := ec.ResolverMiddleware(ctx, func(ctx context.Context) (interface{}, error) {
 					return ec.resolvers.{{ $object.GQLType }}_{{ $field.GQLName }}({{ $field.CallArgs }})
 				})
 				if err != nil {
-					ec.Error(err)
+					ec.Error(ctx, err)
 					return graphql.Null
 				}
 				if resTmp == nil {

codegen/templates/generated.gotpl

@@ -44,7 +44,7 @@ func (e *executableSchema) Query(ctx context.Context, op *query.Operation) *grap
 			Errors: ec.Errors,
 		}
 	{{- else }}
-		return &graphql.Response{Errors: []*errors.QueryError{ {Message: "queries are not supported"} }}
+		return graphql.ErrorResponse(ctx, "queries are not supported")
 	{{- end }}
 }
 
@@ -64,7 +64,7 @@ func (e *executableSchema) Mutation(ctx context.Context, op *query.Operation) *g
 			Errors: ec.Errors,
 		}
 	{{- else }}
-		return &graphql.Response{Errors: []*errors.QueryError{ {Message: "mutations are not supported"} }}
+		return graphql.ErrorResponse(ctx, "mutations are not supported")
 	{{- end }}
 }
 
@@ -96,7 +96,7 @@ func (e *executableSchema) Subscription(ctx context.Context, op *query.Operation
 			}
 		}
 	{{- else }}
-		return graphql.OneShot(&graphql.Response{Errors: []*errors.QueryError{ {Message: "subscriptions are not supported"} }})
+		return graphql.OneShot(graphql.ErrorResponse(ctx, "subscriptions are not supported"))
 	{{- end }}
 }
 

codegen/templates/object.gotpl

@@ -6,9 +6,11 @@ var {{ $object.GQLType|lcFirst}}Implementors = {{$object.Implementors}}
 {{- if .Stream }}
 func (ec *executionContext) _{{$object.GQLType}}(ctx context.Context, sel []query.Selection) func() graphql.Marshaler {
 	fields := graphql.CollectFields(ec.Doc, sel, {{$object.GQLType|lcFirst}}Implementors, ec.Variables)
-
+	ctx = graphql.WithResolverContext(ctx, &graphql.ResolverContext{
+		Object: {{$object.GQLType|quote}},
+	})
 	if len(fields) != 1 {
-		ec.Errorf("must subscribe to exactly one stream")
+		ec.Errorf(ctx, "must subscribe to exactly one stream")
 		return nil
 	}
 
@@ -24,6 +26,11 @@ func (ec *executionContext) _{{$object.GQLType}}(ctx context.Context, sel []quer
 {{- else }}
 func (ec *executionContext) _{{$object.GQLType}}(ctx context.Context, sel []query.Selection{{if not $object.Root}}, obj *{{$object.FullName}} {{end}}) graphql.Marshaler {
 	fields := graphql.CollectFields(ec.Doc, sel, {{$object.GQLType|lcFirst}}Implementors, ec.Variables)
+	{{if $object.Root}}
+		ctx = graphql.WithResolverContext(ctx, &graphql.ResolverContext{
+			Object: {{$object.GQLType|quote}},
+		})
+	{{end}}
 	out := graphql.NewOrderedMap(len(fields))
 	for i, field := range fields {
 		out.Keys[i] = field.Alias

example/scalars/scalar_test.go

@@ -59,7 +59,7 @@ func TestScalars(t *testing.T) {
 		var resp struct{ Search []RawUser }
 
 		err := c.Post(`{ search(input:{createdAfter:"2014"}) { id } }`, &resp)
-		require.EqualError(t, err, "errors: [graphql: time should be a unix timestamp]")
+		require.EqualError(t, err, `[{"message":"time should be a unix timestamp"}]`)
 	})
 
 	t.Run("scalar resolver methods", func(t *testing.T) {

example/starwars/starwars_test.go

@@ -215,7 +215,7 @@ func TestStarwars(t *testing.T) {
 		  }
 		}`, &resp, client.Var("episode", "INVALID"))
 
-		require.EqualError(t, err, "errors: [graphql: INVALID is not a valid Episode]")
+		require.EqualError(t, err, `[{"message":"INVALID is not a valid Episode"}]`)
 	})
 
 	t.Run("introspection", func(t *testing.T) {

example/todo/server/server.go

@@ -16,7 +16,8 @@ func main() {
 	http.Handle("/query", handler.GraphQL(
 		todo.MakeExecutableSchema(todo.New()),
 		handler.RecoverFunc(func(ctx context.Context, err interface{}) error {
-			log.Printf("send this panic somewhere")
+			// send this panic somewhere
+			log.Print(err)
 			debug.PrintStack()
 			return errors.New("user message on panic")
 		}),

example/todo/todo_test.go

@@ -80,7 +80,7 @@ func TestTodo(t *testing.T) {
 		}
 		err := c.Post(`{ todo(id:666) { text } }`, &resp)
 
-		require.EqualError(t, err, "errors: [graphql: internal system error]")
+		require.EqualError(t, err, `[{"message":"internal system error","path":["todo"]}]`)
 	})
 
 	t.Run("select all", func(t *testing.T) {

graphql/context.go

@@ -3,7 +3,6 @@ package graphql
 import (
 	"context"
 
-	"github.com/vektah/gqlgen/neelance/errors"
 	"github.com/vektah/gqlgen/neelance/query"
 )
 
@@ -12,7 +11,7 @@ type ResolverMiddleware func(ctx context.Context, next Resolver) (res interface{
 type RequestMiddleware func(ctx context.Context, next func(ctx context.Context) []byte) []byte
 
 type RequestContext struct {
-	errors.Builder
+	ErrorBuilder
 
 	RawQuery           string
 	Variables          map[string]interface{}
@@ -49,6 +48,20 @@ type ResolverContext struct {
 	Args map[string]interface{}
 	// The raw field
 	Field CollectedField
+	// The path of fields to get to this resolver
+	Path []interface{}
+}
+
+func (r *ResolverContext) PushField(alias string) {
+	r.Path = append(r.Path, alias)
+}
+
+func (r *ResolverContext) PushIndex(index int) {
+	r.Path = append(r.Path, index)
+}
+
+func (r *ResolverContext) Pop() {
+	r.Path = r.Path[0 : len(r.Path)-1]
 }
 
 func GetResolverContext(ctx context.Context) *ResolverContext {
@@ -61,6 +74,14 @@ func GetResolverContext(ctx context.Context) *ResolverContext {
 }
 
 func WithResolverContext(ctx context.Context, rc *ResolverContext) context.Context {
+	parent := GetResolverContext(ctx)
+	rc.Path = nil
+	if parent != nil {
+		rc.Path = append(rc.Path, parent.Path...)
+	}
+	if rc.Field.Alias != "" {
+		rc.PushField(rc.Field.Alias)
+	}
 	return context.WithValue(ctx, resolver, rc)
 }
 

graphql/error.go

@@ -1,36 +1,49 @@
 package graphql
 
 import (
-	"github.com/vektah/gqlgen/neelance/errors"
+	"context"
+	"fmt"
+	"sync"
 )
 
-func MarshalErrors(errs []*errors.QueryError) Marshaler {
-	res := Array{}
-	for _, err := range errs {
-		res = append(res, MarshalError(err))
+type ErrorPresenterFunc func(context.Context, error) error
+
+func DefaultErrorPresenter(ctx context.Context, err error) error {
+	return &ResolverError{
+		Message: err.Error(),
+		Path:    GetResolverContext(ctx).Path,
 	}
-	return res
 }
 
-func MarshalError(err *errors.QueryError) Marshaler {
-	if err == nil {
-		return Null
-	}
+// ResolverError is the default error type returned by ErrorPresenter. You can replace it with your own by returning
+// something different from the ErrorPresenter
+type ResolverError struct {
+	Message string        `json:"message"`
+	Path    []interface{} `json:"path,omitempty"`
+}
 
-	errObj := &OrderedMap{}
-	errObj.Add("message", MarshalString(err.Message))
+func (r *ResolverError) Error() string {
+	return r.Message
+}
 
-	if len(err.Locations) > 0 {
-		locations := Array{}
-		for _, location := range err.Locations {
-			locationObj := &OrderedMap{}
-			locationObj.Add("line", MarshalInt(location.Line))
-			locationObj.Add("column", MarshalInt(location.Column))
+type ErrorBuilder struct {
+	Errors []error
+	// ErrorPresenter will be used to generate the error
+	// message from errors given to Error().
+	ErrorPresenter ErrorPresenterFunc
+	mu             sync.Mutex
+}
 
-			locations = append(locations, locationObj)
-		}
+func (c *ErrorBuilder) Errorf(ctx context.Context, format string, args ...interface{}) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
 
-		errObj.Add("locations", locations)
-	}
-	return errObj
+	c.Errors = append(c.Errors, c.ErrorPresenter(ctx, fmt.Errorf(format, args...)))
+}
+
+func (c *ErrorBuilder) Error(ctx context.Context, err error) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	c.Errors = append(c.Errors, c.ErrorPresenter(ctx, err))
 }