Feat(GraphQL): This PR allows to return errors from custom REST endpoint.

graphql/e2e/custom_logic/cmd/main.go

@@ -249,6 +249,20 @@ func getDefaultResponse() []byte {
 	return []byte(resTemplate)
 }
 
+func getFavMoviesErrorHandler(w http.ResponseWriter, r *http.Request) {
+	err := verifyRequest(r, expectedRequest{
+		method:    http.MethodGet,
+		urlSuffix: "/0x123?name=Author&num=10",
+		body:      "",
+		headers:   nil,
+	})
+	if err != nil {
+		check2(w.Write([]byte(err.Error())))
+		return
+	}
+	check2(w.Write([]byte(`{"errors":[{"message": "Rest API returns Error for myFavoriteMovies query"}]}`)))
+}
+
 func getFavMoviesHandler(w http.ResponseWriter, r *http.Request) {
 	err := verifyRequest(r, expectedRequest{
 		method:    http.MethodGet,
@@ -398,6 +412,21 @@ func favMoviesCreateHandler(w http.ResponseWriter, r *http.Request) {
     ]`)))
 }
 
+func favMoviesCreateErrorHandler(w http.ResponseWriter, r *http.Request) {
+	err := verifyRequest(r, expectedRequest{
+		method:    http.MethodPost,
+		urlSuffix: "/favMoviesCreateError",
+		body:      `{"movies":[{"director":[{"name":"Dir1"}],"name":"Mov1"},{"name":"Mov2"}]}`,
+		headers:   nil,
+	})
+	if err != nil {
+		check2(w.Write([]byte(err.Error())))
+		return
+	}
+
+	check2(w.Write([]byte(`{"errors":[{"message": "Rest API returns Error for FavoriteMoviesCreate query"}]}`)))
+}
+
 func favMoviesCreateWithNullBodyHandler(w http.ResponseWriter, r *http.Request) {
 	err := verifyRequest(r, expectedRequest{
 		method:    http.MethodPost,
@@ -836,6 +865,10 @@ func userNameHandler(w http.ResponseWriter, r *http.Request) {
 	nameHandler(w, r, &inputBody)
 }
 
+func userNameErrorHandler(w http.ResponseWriter, r *http.Request) {
+	check2(w.Write([]byte(`{"errors":[{"message": "Rest API returns Error for field name"}]}`)))
+}
+
 func userNameWithoutAddressHandler(w http.ResponseWriter, r *http.Request) {
 	expectedRequest := expectedRequest{
 		body: `{"uid":"0x5"}`,
@@ -1210,6 +1243,7 @@ func main() {
 
 	// for queries
 	http.HandleFunc("/favMovies/", getFavMoviesHandler)
+	http.HandleFunc("/favMoviesError/", getFavMoviesErrorHandler)
 	http.HandleFunc("/favMoviesPost/", postFavMoviesHandler)
 	http.HandleFunc("/favMoviesPostWithBody/", postFavMoviesWithBodyHandler)
 	http.HandleFunc("/verifyHeaders", verifyHeadersHandler)
@@ -1218,6 +1252,7 @@ func main() {
 
 	// for mutations
 	http.HandleFunc("/favMoviesCreate", favMoviesCreateHandler)
+	http.HandleFunc("/favMoviesCreateError", favMoviesCreateErrorHandler)
 	http.HandleFunc("/favMoviesUpdate/", favMoviesUpdateHandler)
 	http.HandleFunc("/favMoviesDelete/", favMoviesDeleteHandler)
 	http.HandleFunc("/favMoviesCreateWithNullBody", favMoviesCreateWithNullBodyHandler)
@@ -1232,6 +1267,7 @@ func main() {
 
 	// for testing single mode
 	http.HandleFunc("/userName", userNameHandler)
+	http.HandleFunc("/userNameError", userNameErrorHandler)
 	http.HandleFunc("/userNameWithoutAddress", userNameWithoutAddressHandler)
 	http.HandleFunc("/checkHeadersForUserName", userNameHandlerWithHeaders)
 	http.HandleFunc("/car", carHandler)

graphql/e2e/custom_logic/custom_logic_test.go

@@ -2808,3 +2808,182 @@ func TestCustomDQL(t *testing.T) {
 		]
 	  }`, string(result.Data))
 }
+
+func TestCustomGetQuerywithRESTError(t *testing.T) {
+	schema := customTypes + `
+	 type Query {
+		 myFavoriteMovies(id: ID!, name: String!, num: Int): [Movie] @custom(http: {
+				 url: "http://mock:8888/favMoviesError/$id?name=$name&num=$num",
+				 method: "GET"
+		 })
+	 }`
+	updateSchemaRequireNoGQLErrors(t, schema)
+	time.Sleep(2 * time.Second)
+
+	query := `
+	 query {
+		 myFavoriteMovies(id: "0x123", name: "Author", num: 10) {
+			 id
+			 name
+			 director {
+				 id
+				 name
+			 }
+		 }
+	 }`
+	params := &common.GraphQLParams{
+		Query: query,
+	}
+
+	result := params.ExecuteAsPost(t, alphaURL)
+	require.Equal(t, x.GqlErrorList{
+		{
+			Message: "Rest API returns Error for myFavoriteMovies query",
+		},
+	}, result.Errors)
+
+}
+
+func TestCustomFieldsWithRestError(t *testing.T) {
+	schema := `
+    type Car @remote {
+		id: ID! 
+		name: String!
+	}
+
+	type User {
+		id: String! @id @search(by: [hash, regexp])
+		name: String
+			@custom(
+				http: {
+					url: "http://mock:8888//userNameError"
+					method: "GET"
+					body: "{uid: $id}"
+					mode: SINGLE,
+				}
+			)
+		age: Int! @search
+		cars: Car
+		@custom(
+			http: {
+			url: "http://mock:8888/cars"
+			method: "GET"
+			body: "{uid: $id}"
+			mode: BATCH,
+			}
+	      )		
+  	}
+  `
+
+	updateSchemaRequireNoGQLErrors(t, schema)
+	time.Sleep(2 * time.Second)
+
+	params := &common.GraphQLParams{
+		Query: `mutation addUser {
+			 addUser(input: [{ id:"0x1", age: 10 }]) {
+				 user {
+					 id
+					 age
+				 }
+			 }
+		 }`,
+	}
+
+	result := params.ExecuteAsPost(t, alphaURL)
+	common.RequireNoGQLErrors(t, result)
+
+	queryUser := `
+	query ($id: String!){
+		queryUser(filter: {id: {eq: $id}}) {
+			id
+			name
+			age
+			cars{
+			  name
+			}
+		}
+	}`
+
+	params = &common.GraphQLParams{
+		Query:     queryUser,
+		Variables: map[string]interface{}{"id": "0x1"},
+	}
+
+	result = params.ExecuteAsPost(t, alphaURL)
+
+	expected := `
+	{
+      "queryUser": [
+        {
+          "id": "0x1",
+          "name": null,
+          "age": 10,
+          "cars": {
+            "name": "car-0x1"
+        }	
+        }
+      ]
+    }`
+
+	require.Equal(t, x.GqlErrorList{
+		{
+			Message: "Rest API returns Error for field name",
+		},
+	}, result.Errors)
+
+	require.JSONEq(t, expected, string(result.Data))
+
+}
+
+func TestCustomPostMutationWithRESTError(t *testing.T) {
+	schema := customTypes + `
+	input MovieDirectorInput {
+		id: ID
+		name: String
+		directed: [MovieInput]
+	}
+	input MovieInput {
+		id: ID
+		name: String
+		director: [MovieDirectorInput]
+	}
+	type Mutation {
+        createMyFavouriteMovies(input: [MovieInput!]): [Movie] @custom(http: {
+			url: "http://mock:8888/favMoviesCreateError",
+			method: "POST",
+			body: "{ movies: $input}"
+        })
+	}`
+	updateSchemaRequireNoGQLErrors(t, schema)
+	time.Sleep(2 * time.Second)
+
+	params := &common.GraphQLParams{
+		Query: `
+		mutation createMovies($movs: [MovieInput!]) {
+			createMyFavouriteMovies(input: $movs) {
+				id
+				name
+				director {
+					id
+					name
+				}
+			}
+		}`,
+		Variables: map[string]interface{}{
+			"movs": []interface{}{
+				map[string]interface{}{
+					"name":     "Mov1",
+					"director": []interface{}{map[string]interface{}{"name": "Dir1"}},
+				},
+				map[string]interface{}{"name": "Mov2"},
+			}},
+	}
+
+	result := params.ExecuteAsPost(t, alphaURL)
+	require.Equal(t, x.GqlErrorList{
+		{
+			Message: "Rest API returns Error for FavoriteMoviesCreate query",
+		},
+	}, result.Errors)
+
+}

graphql/resolve/resolver.go

@@ -889,6 +889,10 @@ func resolveCustomField(f schema.Field, vals []interface{}, mu *sync.RWMutex, er
 		// To collect errors from remote GraphQL endpoint and those encountered during execution.
 		var errs error
 		var result []interface{}
+		type RESTErr struct{
+			Errors x.GqlErrorList `json:"errors,omitempty"`
+		}
+		var customErr RESTErr
 		if graphql {
 			resp := &graphqlResp{}
 			err = json.Unmarshal(b, resp)
@@ -906,6 +910,10 @@ func resolveCustomField(f schema.Field, vals []interface{}, mu *sync.RWMutex, er
 				errCh <- schema.AppendGQLErrs(errs, keyNotFoundError(f, fconf.RemoteGqlQueryName))
 				return
 			}
+		} else if err := json.Unmarshal(b, &customErr); err == nil && len(customErr.Errors)!=0 {
+			errCh<-customErr.Errors
+			return
+
 		} else if err := json.Unmarshal(b, &result); err != nil {
 			errCh <- x.GqlErrorList{jsonUnmarshalError(err, f)}
 			return
@@ -979,11 +987,14 @@ func resolveCustomField(f schema.Field, vals []interface{}, mu *sync.RWMutex, er
 			}
 
 			var result interface{}
+			type RESTErr struct{
+				Errors x.GqlErrorList `json:"errors,omitempty"`
+			}
+			var customErr RESTErr
 			var errs error
 			if graphql {
 				resp := &graphqlResp{}
-				err = json.Unmarshal(b, resp)
-				if err != nil {
+				if err = json.Unmarshal(b, resp); err != nil {
 					errChan <- x.GqlErrorList{jsonUnmarshalError(err, f)}
 					return
 				}
@@ -998,6 +1009,10 @@ func resolveCustomField(f schema.Field, vals []interface{}, mu *sync.RWMutex, er
 						keyNotFoundError(f, fconf.RemoteGqlQueryName))
 					return
 				}
+			} else if err := json.Unmarshal(b, &customErr); err == nil && len(customErr.Errors)!=0 {
+				errCh<-customErr.Errors
+				return
+
 			} else if err := json.Unmarshal(b, &result); err != nil {
 				errChan <- x.GqlErrorList{jsonUnmarshalError(err, f)}
 				return
@@ -1848,12 +1863,20 @@ func (hr *httpResolver) rewriteAndExecute(ctx context.Context, field schema.Fiel
 	// this means it had body and not graphql, so just unmarshal it and return
 	if hrc.RemoteGqlQueryName == "" {
 		var result interface{}
-		if err := json.Unmarshal(b, &result); err != nil {
-			return emptyResult(jsonUnmarshalError(err, field))
+		type RESTErr struct{
+			Errors x.GqlErrorList `json:"errors,omitempty"`
+		}
+		var customErr  RESTErr
+		if err := json.Unmarshal(b, &customErr); err != nil || len(customErr.Errors)==0 {
+			if err := json.Unmarshal(b, &result); err != nil {
+				return emptyResult(jsonUnmarshalError(err, field))
+			}
+
 		}
 		return &Resolved{
 			Data:  map[string]interface{}{field.Name(): result},
 			Field: field,
+			Err: customErr.Errors,
 		}
 	}