handle errors in ExecuteSubscribe

Author: remorses

subscription.go

@@ -106,18 +106,18 @@ func ExecuteSubscription(p ExecuteParams) chan *Result {
 	}
 	var resultChannel = make(chan *Result)
 	go func() {
+		defer close(resultChannel)
 		defer func() {
 			if err := recover(); err != nil {
 				e, ok := err.(error)
 				if !ok {
 					fmt.Println("strange program path")
 					return
 				}
-				sendOneResultAndClose(&Result{
+				resultChannel <- &Result{
 					Errors: gqlerrors.FormatErrors(e),
-				})
+				}
 			}
-			// close(resultChannel)
 			return
 		}()
 
@@ -132,17 +132,19 @@ func ExecuteSubscription(p ExecuteParams) chan *Result {
 		})
 
 		if err != nil {
-			sendOneResultAndClose(&Result{
+			resultChannel <- &Result{
 				Errors: gqlerrors.FormatErrors(err),
-			})
+			}
+
 			return
 		}
 
 		operationType, err := getOperationRootType(p.Schema, exeContext.Operation)
 		if err != nil {
-			sendOneResultAndClose(&Result{
+			resultChannel <- &Result{
 				Errors: gqlerrors.FormatErrors(err),
-			})
+			}
+
 			return
 		}
 
@@ -163,18 +165,20 @@ func ExecuteSubscription(p ExecuteParams) chan *Result {
 		fieldDef := getFieldDef(p.Schema, operationType, fieldName)
 
 		if fieldDef == nil {
-			sendOneResultAndClose(&Result{
+			resultChannel <- &Result{
 				Errors: gqlerrors.FormatErrors(fmt.Errorf("the subscription field %q is not defined", fieldName)),
-			})
+			}
+
 			return
 		}
 
 		resolveFn := fieldDef.Subscribe
 
 		if resolveFn == nil {
-			sendOneResultAndClose(&Result{
+			resultChannel <- &Result{
 				Errors: gqlerrors.FormatErrors(fmt.Errorf("the subscription function %q is not defined", fieldName)),
-			})
+			}
+
 			return
 		}
 		fieldPath := &ResponsePath{
@@ -202,16 +206,18 @@ func ExecuteSubscription(p ExecuteParams) chan *Result {
 			Context: p.Context,
 		})
 		if err != nil {
-			sendOneResultAndClose(&Result{
+			resultChannel <- &Result{
 				Errors: gqlerrors.FormatErrors(err),
-			})
+			}
+
 			return
 		}
 
 		if fieldResult == nil {
-			sendOneResultAndClose(&Result{
+			resultChannel <- &Result{
 				Errors: gqlerrors.FormatErrors(fmt.Errorf("no field result")),
-			})
+			}
+
 			return
 		}
 
@@ -222,13 +228,13 @@ func ExecuteSubscription(p ExecuteParams) chan *Result {
 				select {
 				case <-p.Context.Done():
 					println("context cancelled")
-					close(resultChannel)
+
 					// TODO send the context error to the resultchannel
 					return
 
 				case res, more := <-sub:
 					if !more {
-						close(resultChannel)
+
 						return
 					}
 					resultChannel <- mapSourceToResponse(res)
@@ -237,7 +243,7 @@ func ExecuteSubscription(p ExecuteParams) chan *Result {
 		default:
 			fmt.Println(fieldResult)
 			resultChannel <- mapSourceToResponse(fieldResult)
-			close(resultChannel)
+
 			return
 		}
 	}()

subscription_test.go

@@ -1,6 +1,7 @@
 package graphql_test
 
 import (
+	"errors"
 	"fmt"
 	"testing"
 
@@ -84,7 +85,7 @@ func TestSchemaSubscribe(t *testing.T) {
 			},
 		},
 		{
-			Name: "receive parse error",
+			Name: "receive query validation error",
 			Schema: makeSubscriptionSchema(t, graphql.ObjectConfig{
 				Name: "Subscription",
 				Fields: graphql.Fields{
@@ -171,52 +172,30 @@ func TestSchemaSubscribe(t *testing.T) {
 			},
 		},
 
-		// {
-		// 	Name:   "parse_errors",
-		// 	Schema: schema,
-		// 	Query:  `invalid graphQL query`,
-		// 	ExpectedResults: []testutil.TestResponse{
-		// 		{
-		// 			Errors: []gqlerrors.FormattedError{{Message: ""}},
-		// 		},
-		// 	},
-		// },
-		// {
-		// 	Name:   "subscribe_to_query_succeeds",
-		// 	Schema: schema,
-		// 	Query: `
-		// 		query Hello {
-		// 			hello
-		// 		}
-		// 	`,
-		// 	ExpectedResults: []testutil.TestResponse{
-		// 		{
-		// 			Data: json.RawMessage(`
-		// 				{
-		// 					"hello": "Hello world!"
-		// 				}
-		// 			`),
-		// 		},
-		// 	},
-		// },
-		// {
-		// 	Name:   "subscription_resolver_can_error",
-		// 	Schema: schema,
-		// 	Query: `
-		// 		subscription onHelloSaid {
-		// 			helloSaid {
-		// 				msg
-		// 			}
-		// 		}
-		// 	`,
-		// 	ExpectedResults: []testutil.TestResponse{
-		// 		{
-		// 			Data: json.RawMessage(`
-		// 				null
-		// 			`),
-		// 			Errors: []gqlerrors.FormattedError{{Message: ""}}},
-		// 	},
-		// },
+		{
+			Name: "subscription_resolver_can_error",
+			Schema: makeSubscriptionSchema(t, graphql.ObjectConfig{
+				Name: "Subscription",
+				Fields: graphql.Fields{
+					"should_error": &graphql.Field{
+						Type: graphql.String,
+						Subscribe: func(p graphql.ResolveParams) (interface{}, error) {
+							return nil, errors.New("got a subscribe error")
+						},
+					},
+				},
+			}),
+			Query: `
+				subscription {
+					should_error
+				}
+			`,
+			ExpectedResults: []testutil.TestResponse{
+				{
+					Errors: []string{"got a subscribe error"},
+				},
+			},
+		},
 		// {
 		// 	Name:   "subscription_resolver_can_error_optional_msg",
 		// 	Schema: schema,