fix multi-goroutine request error (#54)

* fix multi-goroutine bug and add multi-goroutine request test
1. panic: concurrent write to websocket connection
2. request GetSceneList: mismatched ID: expected response with ID c30f63f4-0065-4cb0-5873-19e12a676ee1, but got 97362273-a871-415b-6610-45894239012e

* generate goroutine test

* these tests actually don't have to be generated

put them in a separate file

* add goroutine test

---------

Co-authored-by: Andrey Kaipov <andreykaipov@users.noreply.github.com>

api/client.go

@@ -3,6 +3,7 @@ package api
 import (
 	"encoding/json"
 	"fmt"
+	"sync"
 	"time"
 
 	"github.com/andreykaipov/goobs/api/opcodes"
@@ -24,6 +25,7 @@ type Client struct {
 	IncomingResponses chan *opcodes.RequestResponse
 	Opcodes           chan opcodes.Opcode
 	Log               Logger
+	mutex             sync.Mutex
 }
 
 // SendRequest abstracts the logic every subclient uses to send a request and
@@ -56,6 +58,9 @@ func (c *Client) SendRequest(requestBody Params, responseBody interface{}) error
 
 	c.Log.Printf("[INFO] Sending %s Request with ID %s", name, id)
 
+	c.mutex.Lock()
+	defer c.mutex.Unlock()
+
 	c.Opcodes <- &opcodes.Request{
 		Type: name,
 		ID:   id,

client_test.go

@@ -0,0 +1,54 @@
+package goobs_test
+
+import (
+	"net"
+	"net/http"
+	"os"
+	"sync"
+	"testing"
+
+	goobs "github.com/andreykaipov/goobs"
+	"github.com/gorilla/websocket"
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_client(t *testing.T) {
+	var err error
+	_, err = goobs.New(
+		"localhost:"+os.Getenv("OBS_PORT"),
+		goobs.WithPassword("wrongpassword"),
+		goobs.WithRequestHeader(http.Header{"User-Agent": []string{"goobs-e2e/0.0.0"}}),
+	)
+	assert.Error(t, err)
+	assert.IsType(t, &websocket.CloseError{}, err)
+	assert.Equal(t, err.(*websocket.CloseError).Code, 4009)
+	_, err = goobs.New(
+		"localhost:42069",
+		goobs.WithPassword("wrongpassword"),
+		goobs.WithRequestHeader(http.Header{"User-Agent": []string{"goobs-e2e/0.0.0"}}),
+	)
+	assert.Error(t, err)
+	assert.IsType(t, &net.OpError{}, err)
+}
+
+func Test_multi_goroutine(t *testing.T) {
+	client, err := goobs.New(
+		"localhost:"+os.Getenv("OBS_PORT"),
+		goobs.WithPassword("goodpassword"),
+		goobs.WithRequestHeader(http.Header{"User-Agent": []string{"goobs-e2e/0.0.0"}}),
+	)
+	assert.NoError(t, err)
+	t.Cleanup(func() {
+		client.Disconnect()
+	})
+	wg := sync.WaitGroup{}
+	for i := 0; i < 1000; i++ {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			_, err := client.Scenes.GetSceneList()
+			assert.NoError(t, err)
+		}()
+	}
+	wg.Wait()
+}

internal/generate/tests/main.go

@@ -84,8 +84,6 @@ func main() {
 	f := NewFile("goobs_test")
 	f.HeaderComment("This file has been automatically generated. Don't edit it.")
 
-	f.Add(generateClientTest().Line())
-
 	// find subclients at the root of goobs, using that to then find the
 	// structs within each of the subclient categories
 
@@ -114,38 +112,6 @@ func main() {
 	}
 }
 
-func generateClientTest() *Statement {
-	s := Line()
-
-	s.Func().Id("Test_client").Params(Id("t").Op("*").Qual("testing", "T")).Block(
-		Var().Id("err").Error(),
-		// tries to connect incorrectly
-		List(Id("_"), Id("err")).Op("=").Qual(goobs, "New").Call(
-			Lit("localhost:").Op("+").Qual("os", "Getenv").Call(Lit("OBS_PORT")),
-			Qual(goobs, "WithPassword").Call(Lit("wrongpassword")),
-			Qual(goobs, "WithRequestHeader").Call(Qual("net/http", "Header").Values(Dict{
-				Lit("User-Agent"): Index().String().Values(Lit("goobs-e2e/0.0.0")),
-			})),
-		),
-		Qual(assert, "Error").Call(Id("t"), Id("err")),
-		Qual(assert, "IsType").Call(Id("t"), Op("&").Qual(websocket, "CloseError").Block(), Id("err")),
-		Qual(assert, "Equal").Call(Id("t"), Id("err").Assert(Op("*").Qual(websocket, "CloseError")).Dot("Code"), Lit(4009)),
-
-		// tries to connect to a nonrunning server
-		List(Id("_"), Id("err")).Op("=").Qual(goobs, "New").Call(
-			Lit("localhost:42069"),
-			Qual(goobs, "WithPassword").Call(Lit("wrongpassword")),
-			Qual(goobs, "WithRequestHeader").Call(Qual("net/http", "Header").Values(Dict{
-				Lit("User-Agent"): Index().String().Values(Lit("goobs-e2e/0.0.0")),
-			})),
-		),
-		Qual(assert, "Error").Call(Id("t"), Id("err")),
-		Qual(assert, "IsType").Call(Id("t"), Op("&").Qual("net", "OpError").Block(), Id("err")),
-	)
-
-	return s
-}
-
 func generateRequestTest(subclient, category string, structs map[string]StructFieldMap) *Statement {
 	paramsMapper := func(request, field, fieldType string) *Statement {
 		var val *Statement

test.sh

@@ -11,6 +11,7 @@ setup() {
                 echo "Main OBS container is already running"
         else
                 docker run --rm --detach --name obs -e vnc=1 -p 5900:5900 -p 4455:1234 ghcr.io/andreykaipov/goobs
+                sleep 3
         fi
 
         # record and stream categories aren't totally idempotent so we need
@@ -26,7 +27,7 @@ setup() {
 
 gotest() {
         category="$1"
-        go test -v -run="^Test_$category$" -coverprofile=cover.out -coverpkg=./... -covermode=$covermode ./zz_generated.*test.go
+        go test -v -run="^Test_$category$" -coverprofile=cover.out -coverpkg=./... -covermode=$covermode ./...
         awk 'NR>1' cover.out >>coverall.out
 }
 
@@ -39,20 +40,21 @@ main() {
         # note: `scenes` and `transitions` must be ran after `ui`
         #
         categories='
-		client
-		config
-		filters
-		general
-		inputs
-		mediainputs
-		outputs
-		rconfig
-		sceneitems
-		sources
-		ui
-		scenes
-		transitions
-	'
+                client
+                multi_goroutine
+                config
+                filters
+                general
+                inputs
+                mediainputs
+                outputs
+                rconfig
+                sceneitems
+                sources
+                ui
+                scenes
+                transitions
+        '
 
         for category in $categories; do
                 echo "$category"

zz_generated._test.go

@@ -3,7 +3,6 @@
 package goobs_test
 
 import (
-	"net"
 	"net/http"
 	"os"
 	"testing"
@@ -23,29 +22,9 @@ import (
 	transitions "github.com/andreykaipov/goobs/api/requests/transitions"
 	ui "github.com/andreykaipov/goobs/api/requests/ui"
 	typedefs "github.com/andreykaipov/goobs/api/typedefs"
-	websocket "github.com/gorilla/websocket"
 	assert "github.com/stretchr/testify/assert"
 )
 
-func Test_client(t *testing.T) {
-	var err error
-	_, err = goobs.New(
-		"localhost:"+os.Getenv("OBS_PORT"),
-		goobs.WithPassword("wrongpassword"),
-		goobs.WithRequestHeader(http.Header{"User-Agent": []string{"goobs-e2e/0.0.0"}}),
-	)
-	assert.Error(t, err)
-	assert.IsType(t, &websocket.CloseError{}, err)
-	assert.Equal(t, err.(*websocket.CloseError).Code, 4009)
-	_, err = goobs.New(
-		"localhost:42069",
-		goobs.WithPassword("wrongpassword"),
-		goobs.WithRequestHeader(http.Header{"User-Agent": []string{"goobs-e2e/0.0.0"}}),
-	)
-	assert.Error(t, err)
-	assert.IsType(t, &net.OpError{}, err)
-}
-
 func Test_config(t *testing.T) {
 	client, err := goobs.New(
 		"localhost:"+os.Getenv("OBS_PORT"),