func completeValueCatchingError(eCtx *ExecutionContext, returnType Type, fieldASTs []*ast.Field, info ResolveInfo, result interface{}) (completed interface{}) {
// catch panic
defer func() interface{} {
if r := recover(); r != nil {
//send panic upstream
if _, ok := returnType.(*NonNull); ok {
panic(r)
}
if err, ok := r.(gqlerrors.FormattedError); ok {
eCtx.Errors = append(eCtx.Errors, err)
}
return completed
}
return completed
}()
if returnType, ok := returnType.(*NonNull); ok {
completed := completeValue(eCtx, returnType, fieldASTs, info, result)
return completed
}
completed = completeValue(eCtx, returnType, fieldASTs, info, result)
resultVal := reflect.ValueOf(completed)
if resultVal.IsValid() && resultVal.Type().Kind() == reflect.Func {
if propertyFn, ok := completed.(func() interface{}); ok {
return propertyFn()
}
err := gqlerrors.NewFormattedError("Error resolving func. Expected `func() interface{}` signature")
panic(gqlerrors.FormatError(err))
}
return completed
}
func invariant(condition bool, message string) error {
if !condition {
return gqlerrors.NewFormattedError(message)
}
return nil
}
func completeValue(eCtx *ExecutionContext, returnType Type, fieldASTs []*ast.Field, info ResolveInfo, result interface{}) interface{} {
// TODO: explore resolving go-routines in completeValue
resultVal := reflect.ValueOf(result)
if resultVal.IsValid() && resultVal.Type().Kind() == reflect.Func {
if propertyFn, ok := result.(func() interface{}); ok {
return propertyFn()
}
err := gqlerrors.NewFormattedError("Error resolving func. Expected `func() interface{}` signature")
panic(gqlerrors.FormatError(err))
}
if returnType, ok := returnType.(*NonNull); ok {
completed := completeValue(eCtx, returnType.OfType, fieldASTs, info, result)
if completed == nil {
err := NewLocatedError(
fmt.Sprintf("Cannot return null for non-nullable field %v.%v.", info.ParentType, info.FieldName),
FieldASTsToNodeASTs(fieldASTs),
)
panic(gqlerrors.FormatError(err))
}
return completed
}
if isNullish(result) {
return nil
}
// If field type is List, complete each item in the list with the inner type
if returnType, ok := returnType.(*List); ok {
resultVal := reflect.ValueOf(result)
err := invariant(
resultVal.IsValid() && resultVal.Type().Kind() == reflect.Slice,
"User Error: expected iterable, but did not find one.",
)
if err != nil {
panic(gqlerrors.FormatError(err))
}
itemType := returnType.OfType
completedResults := []interface{}{}
for i := 0; i < resultVal.Len(); i++ {
val := resultVal.Index(i).Interface()
completedItem := completeValueCatchingError(eCtx, itemType, fieldASTs, info, val)
completedResults = append(completedResults, completedItem)
}
return completedResults
}
// If field type is Scalar or Enum, serialize to a valid value, returning
// null if serialization is not possible.
if returnType, ok := returnType.(*Scalar); ok {
serializedResult := returnType.Serialize(result)
if isNullish(serializedResult) {
return nil
}
return serializedResult
}
if returnType, ok := returnType.(*Enum); ok {
serializedResult := returnType.Serialize(result)
if isNullish(serializedResult) {
return nil
}
return serializedResult
}
// ast.Field type must be Object, Interface or Union and expect sub-selections.
var objectType *Object
switch returnType := returnType.(type) {
case *Object:
objectType = returnType
case Abstract:
objectType = returnType.ObjectType(result, info)
if objectType != nil && !returnType.IsPossibleType(objectType) {
panic(gqlerrors.NewFormattedError(
fmt.Sprintf(`Runtime Object type "%v" is not a possible type `+
`for "%v".`, objectType, returnType),
))
}
}
if objectType == nil {
return nil
}
// If there is an isTypeOf predicate function, call it with the
// current result. If isTypeOf returns false, then raise an error rather
// than continuing execution.
if objectType.IsTypeOf != nil && !objectType.IsTypeOf(result, info) {
panic(gqlerrors.NewFormattedError(
fmt.Sprintf(`Expected value of type "%v" but got: %T.`, objectType, result),
))
}
// Collect sub-fields to execute to complete this value.
subFieldASTs := map[string][]*ast.Field{}
visitedFragmentNames := map[string]bool{}
for _, fieldAST := range fieldASTs {
if fieldAST == nil {
continue
}
selectionSet := fieldAST.SelectionSet
if selectionSet != nil {
innerParams := CollectFieldsParams{
ExeContext: eCtx,
OperationType: objectType,
SelectionSet: selectionSet,
Fields: subFieldASTs,
VisitedFragmentNames: visitedFragmentNames,
}
subFieldASTs = collectFields(innerParams)
}
}
executeFieldsParams := ExecuteFieldsParams{
ExecutionContext: eCtx,
ParentType: objectType,
Source: result,
Fields: subFieldASTs,
}
results := executeFields(executeFieldsParams)
return results.Data
}