adding error interface for better separation of library errors and cl…

…ient errors
tokopedia · Sep 28, 2018 · 02135ef · 02135ef
1 parent b09572f
commit 02135ef
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Showing 3 changed files with 9 additions and 8 deletions.
diff --git a/errors/errors.go b/errors/errors.go
@@ -4,6 +4,10 @@ import (
 	"fmt"
 )
 
+type GraphQLError interface {
+	PrepareExtErr() *QueryError
+}
+
 type QueryError struct {
 	Message       string        `json:"message"`
 	Locations     []Location    `json:"locations,omitempty"`
@@ -78,7 +82,3 @@ func (err *QueryError) AddErrTimestamp(errTime string) *QueryError {
 	err.Extensions.Timestamp = errTime
 	return err
 }
-
-func PrepareExtErr(msg string) *QueryError {
-	return Errorf("%s", msg)
-}
diff --git a/internal/exec/exec.go b/internal/exec/exec.go
@@ -184,8 +184,9 @@ func execFieldSelection(ctx context.Context, r *Request, f *fieldToExec, path *p
 		callOut := f.resolver.Method(f.field.MethodIndex).Call(in)
 		result = callOut[0]
 		if f.field.HasError && !callOut[1].IsNil() {
-			extnErr, ok := callOut[1].Interface().(*errors.QueryError)
+			graphQLErr, ok := callOut[1].Interface().(errors.GraphQLError)
 			if ok {
+				extnErr := graphQLErr.PrepareExtErr()
 				extnErr.Path = path.toSlice()
 				extnErr.ResolverError = errlib.New(extnErr.Message)
 				return extnErr

diff --git a/internal/exec/resolvable/resolvable.go b/internal/exec/resolvable/resolvable.go
@@ -253,7 +253,7 @@ func (b *execBuilder) makeObjectExec(typeName string, fields schema.FieldList, p
 
 var contextType = reflect.TypeOf((*context.Context)(nil)).Elem()
 var errorType = reflect.TypeOf((*error)(nil)).Elem()
-var extnErrorType = reflect.TypeOf((**errors.QueryError)(nil)).Elem()
+var extnErrorInterfaceType = reflect.TypeOf((*errors.GraphQLError)(nil)).Elem()
 
 func (b *execBuilder) makeFieldExec(typeName string, f *schema.Field, m reflect.Method, methodIndex int, methodHasReceiver bool) (*Field, error) {
 	in := make([]reflect.Type, m.Type.NumIn())
@@ -292,8 +292,8 @@ func (b *execBuilder) makeFieldExec(typeName string, f *schema.Field, m reflect.
 
 	hasError := m.Type.NumOut() == 2
 	if hasError {
-		if m.Type.Out(1) != errorType && m.Type.Out(1) != extnErrorType {
-			return nil, fmt.Errorf(`must have "error" or "*errors.QueryError" as its second return value`)
+		if m.Type.Out(1) != errorType && !m.Type.Out(1).Implements(extnErrorInterfaceType) {
+			return nil, fmt.Errorf(`must have "error" or implements errors.GraphQLError interface as its second return value but the type is %v`, m.Type.Out(1))
 		}
 	}