func Execute(p ExecuteParams) (result *Result) {
result = &Result{}
exeContext, err := buildExecutionContext(BuildExecutionCtxParams{
Schema: p.Schema,
Root: p.Root,
AST: p.AST,
OperationName: p.OperationName,
Args: p.Args,
Errors: nil,
Result: result,
Context: p.Context,
})
if err != nil {
result.Errors = append(result.Errors, gqlerrors.FormatError(err))
return
}
defer func() {
if r := recover(); r != nil {
var err error
if r, ok := r.(error); ok {
err = gqlerrors.FormatError(r)
}
exeContext.Errors = append(exeContext.Errors, gqlerrors.FormatError(err))
result.Errors = exeContext.Errors
}
}()
return executeOperation(ExecuteOperationParams{
ExecutionContext: exeContext,
Root: p.Root,
Operation: exeContext.Operation,
})
}
// completeListValue complete a list value by completing each item in the list with the inner type
func completeListValue(eCtx *ExecutionContext, returnType *List, fieldASTs []*ast.Field, info ResolveInfo, result interface{}) interface{} {
resultVal := reflect.ValueOf(result)
parentTypeName := ""
if info.ParentType != nil {
parentTypeName = info.ParentType.Name()
}
err := invariant(
resultVal.IsValid() && resultVal.Type().Kind() == reflect.Slice,
fmt.Sprintf("User Error: expected iterable, but did not find one "+
"for field %v.%v.", parentTypeName, info.FieldName),
)
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
}
func (ctx *ValidationContext) ReportError(err error) {
formattedErr := gqlerrors.FormatError(err)
ctx.errors = append(ctx.errors, formattedErr)
}
func completeValue(eCtx *ExecutionContext, returnType Type, fieldASTs []*ast.Field, info ResolveInfo, result interface{}) interface{} {
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 field type is NonNull, complete for inner type, and throw field error
// if result is null.
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 result value is null-ish (null, undefined, or NaN) then return null.
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 {
return completeListValue(eCtx, returnType, fieldASTs, info, result)
}
// If field type is a leaf type, Scalar or Enum, serialize to a valid value,
// returning null if serialization is not possible.
if returnType, ok := returnType.(*Scalar); ok {
return completeLeafValue(returnType, result)
}
if returnType, ok := returnType.(*Enum); ok {
return completeLeafValue(returnType, result)
}
// If field type is an abstract type, Interface or Union, determine the
// runtime Object type and complete for that type.
if returnType, ok := returnType.(*Union); ok {
return completeAbstractValue(eCtx, returnType, fieldASTs, info, result)
}
if returnType, ok := returnType.(*Interface); ok {
return completeAbstractValue(eCtx, returnType, fieldASTs, info, result)
}
// If field type is Object, execute and complete all sub-selections.
if returnType, ok := returnType.(*Object); ok {
return completeObjectValue(eCtx, returnType, fieldASTs, info, result)
}
// Not reachable. All possible output types have been considered.
err := invariant(false,
fmt.Sprintf(`Cannot complete value of unexpected type "%v."`, returnType),
)
if err != nil {
panic(gqlerrors.FormatError(err))
}
return nil
}
// Resolves the field on the given source object. In particular, this
// figures out the value that the field returns by calling its resolve function,
// then calls completeValue to complete promises, serialize scalars, or execute
// the sub-selection-set for objects.
func resolveField(eCtx *ExecutionContext, parentType *Object, source interface{}, fieldASTs []*ast.Field) (result interface{}, resultState resolveFieldResultState) {
// catch panic from resolveFn
var returnType Output
defer func() (interface{}, resolveFieldResultState) {
if r := recover(); r != nil {
var err error
if r, ok := r.(string); ok {
err = NewLocatedError(
fmt.Sprintf("%v", r),
FieldASTsToNodeASTs(fieldASTs),
)
}
if r, ok := r.(error); ok {
err = gqlerrors.FormatError(r)
}
// send panic upstream
if _, ok := returnType.(*NonNull); ok {
panic(gqlerrors.FormatError(err))
}
eCtx.Errors = append(eCtx.Errors, gqlerrors.FormatError(err))
return result, resultState
}
return result, resultState
}()
fieldAST := fieldASTs[0]
fieldName := ""
if fieldAST.Name != nil {
fieldName = fieldAST.Name.Value
}
fieldDef := getFieldDef(eCtx.Schema, parentType, fieldName)
if fieldDef == nil {
resultState.hasNoFieldDefs = true
return nil, resultState
}
returnType = fieldDef.Type
resolveFn := fieldDef.Resolve
if resolveFn == nil {
resolveFn = DefaultResolveFn
}
// Build a map of arguments from the field.arguments AST, using the
// variables scope to fulfill any variable references.
// TODO: find a way to memoize, in case this field is within a List type.
args, _ := getArgumentValues(fieldDef.Args, fieldAST.Arguments, eCtx.VariableValues)
info := ResolveInfo{
FieldName: fieldName,
FieldASTs: fieldASTs,
ReturnType: returnType,
ParentType: parentType,
Schema: eCtx.Schema,
Fragments: eCtx.Fragments,
RootValue: eCtx.Root,
Operation: eCtx.Operation,
VariableValues: eCtx.VariableValues,
}
var resolveFnError error
result, resolveFnError = resolveFn(ResolveParams{
Source: source,
Args: args,
Info: info,
Context: eCtx.Context,
})
if resolveFnError != nil {
panic(gqlerrors.FormatError(resolveFnError))
}
completed := completeValueCatchingError(eCtx, returnType, fieldASTs, info, result)
return completed, resultState
}