Fix lint errors.

handler/graphql.go

@@ -543,17 +543,20 @@ func processMultipart(r *http.Request, request *params, uploadMaxMemory int64) e
 	for key, path := range uploadsMap {
 		file, header, err := r.FormFile(key)
 		if err != nil {
-			return errors.New(fmt.Sprintf("failed to get key %s from form", key))
+			return fmt.Errorf("failed to get key %s from form", key)
 		}
 		upload = graphql.Upload{
 			File:     file,
 			Size:     header.Size,
 			Filename: header.Filename,
 		}
 		if len(path) != 1 || !strings.HasPrefix(path[0], "variables.") {
-			return errors.New(fmt.Sprintf("invalid value for key %s", key))
+			return fmt.Errorf("invalid value for key %s", key)
+		}
+		err = addUploadToOperations(operations, upload, path[0])
+		if err != nil {
+			return err
 		}
-		addUploadToOperations(operations, upload, path[0])
 	}
 
 	// set request variables
@@ -585,7 +588,7 @@ func addUploadToOperations(operations interface{}, upload graphql.Upload, path s
 		switch idx := p.(type) {
 		case string:
 			if operations == nil {
-				return errors.New(fmt.Sprintf("variables is missing, path: %s", path))
+				return fmt.Errorf("variables is missing, path: %s", path)
 			}
 			if last {
 				operations.(map[string]interface{})[idx] = upload
@@ -594,7 +597,7 @@ func addUploadToOperations(operations interface{}, upload graphql.Upload, path s
 			}
 		case int:
 			if operations == nil {
-				return errors.New(fmt.Sprintf("variables is missing, path: %s", path))
+				return fmt.Errorf("variables is missing, path: %s", path)
 			}
 			if last {
 				operations.([]interface{})[idx] = upload

handler/graphql_test.go

@@ -402,6 +402,7 @@ func TestAddUploadToOperations(t *testing.T) {
 
 	t.Run("fail missing all variables", func(t *testing.T) {
 		file, err := os.Open("path/to/file")
+		require.Nil(t, err)
 		var operations map[string]interface{}
 		upload := graphql.Upload{
 			File:     file,
@@ -421,6 +422,7 @@ func TestAddUploadToOperations(t *testing.T) {
 				"file": nil,
 			},
 		}
+		require.Nil(t, err)
 
 		upload := graphql.Upload{
 			File:     file,
@@ -443,6 +445,7 @@ func TestAddUploadToOperations(t *testing.T) {
 
 	t.Run("valid nested variable", func(t *testing.T) {
 		file, err := os.Open("path/to/file")
+		require.Nil(t, err)
 		operations := map[string]interface{}{
 			"variables": map[string]interface{}{
 				"req": []interface{}{

handler/mock.go

@@ -51,9 +51,7 @@ func (e *executableSchemaMock) Mutation(ctx context.Context, op *ast.OperationDe
 
 func (e *executableSchemaMock) Subscription(ctx context.Context, op *ast.OperationDefinition) func() *graphql.Response {
 	return func() *graphql.Response {
-		select {
-		case <-ctx.Done():
-			return nil
-		}
+		<-ctx.Done()
+		return nil
 	}
 }