all: modernize code (#868)

Use `go fix ./...` to modernize the code.

mcp/cmd_test.go

@@ -200,8 +200,7 @@ func TestStdioContextCancellation(t *testing.T) {
 func TestCmdTransport(t *testing.T) {
 	requireExec(t)
 
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
+	ctx := t.Context()
 
 	cmd := createServerCommand(t, "default")
 
@@ -287,8 +286,7 @@ func TestCommandTransportTerminateDuration(t *testing.T) {
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			ctx, cancel := context.WithCancel(context.Background())
-			defer cancel()
+			ctx := t.Context()
 
 			// Use a command that won't exit when stdin is closed
 			cmd := exec.Command("sleep", "20")

mcp/content_nil_test.go

@@ -22,8 +22,8 @@ func TestContentUnmarshalNil(t *testing.T) {
 	tests := []struct {
 		name    string
 		json    string
-		content interface{}
-		want    interface{}
+		content any
+		want    any
 	}{
 		{
 			name:    "CallToolResult nil Content",
@@ -83,7 +83,7 @@ func TestContentUnmarshalNilWithDifferentTypes(t *testing.T) {
 	tests := []struct {
 		name        string
 		json        string
-		content     interface{}
+		content     any
 		expectError bool
 	}{
 		{
@@ -145,7 +145,7 @@ func TestContentUnmarshalNilWithEmptyContent(t *testing.T) {
 	tests := []struct {
 		name        string
 		json        string
-		content     interface{}
+		content     any
 		expectError bool
 	}{
 		{
@@ -186,7 +186,7 @@ func TestContentUnmarshalNilWithInvalidContent(t *testing.T) {
 	tests := []struct {
 		name        string
 		json        string
-		content     interface{}
+		content     any
 		expectError bool
 	}{
 		{

mcp/mcp_test.go

@@ -676,13 +676,11 @@ func TestServerClosing(t *testing.T) {
 
 	ctx := context.Background()
 	var wg sync.WaitGroup
-	wg.Add(1)
-	go func() {
+	wg.Go(func() {
 		if err := cs.Wait(); err != nil {
 			t.Errorf("server connection failed: %v", err)
 		}
-		wg.Done()
-	}()
+	})
 	if _, err := cs.CallTool(ctx, &CallToolParams{
 		Name:      "greet",
 		Arguments: map[string]any{"Name": "user"},

mcp/schema_cache_test.go

@@ -194,7 +194,7 @@ func TestAddToolWithSharedCache(t *testing.T) {
 	}
 
 	// Simulate stateless server pattern: new server per request, shared cache.
-	for i := 0; i < 3; i++ {
+	for range 3 {
 		s := NewServer(&Implementation{Name: "test", Version: "1.0"}, &ServerOptions{
 			SchemaCache: cache,
 		})

mcp/streamable_bench_test.go

@@ -5,7 +5,6 @@
 package mcp_test
 
 import (
-	"context"
 	"flag"
 	"log"
 	"net/http"
@@ -51,8 +50,7 @@ func BenchmarkStreamableServing(b *testing.B) {
 	httpServer := httptest.NewServer(handler)
 	defer httpServer.Close()
 
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
+	ctx := b.Context()
 	session, err := mcp.NewClient(testImpl, nil).Connect(ctx, &mcp.StreamableClientTransport{Endpoint: httpServer.URL}, nil)
 	if err != nil {
 		b.Fatal(err)
@@ -84,8 +82,7 @@ func BenchmarkStreamableServing_BadSessions(b *testing.B) {
 	httpServer := httptest.NewServer(handler)
 	defer httpServer.Close()
 
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
+	ctx := b.Context()
 
 	if *streamableHeap != "" {
 		writeHeap := func(file string) {

mcp/streamable_test.go

@@ -108,9 +108,7 @@ func TestStreamableTransports(t *testing.T) {
 				}
 				// Now, spin off a goroutine that runs after the sampling request, to
 				// check behavior when the client request has completed.
-				sampleWG.Add(1)
-				go func() {
-					defer sampleWG.Done()
+				sampleWG.Go(func() {
 					<-sampleDone
 					// Test that sampling requests in the tool context fail outside of
 					// tool handling, but succeed on the background context.
@@ -120,7 +118,7 @@ func TestStreamableTransports(t *testing.T) {
 					} {
 						testSample(test)
 					}
-				}()
+				})
 				return &CallToolResult{}, nil, nil
 			})
 
@@ -268,9 +266,7 @@ func TestStreamableConcurrentHandling(t *testing.T) {
 	client := NewClient(testImpl, nil)
 	var wg sync.WaitGroup
 	for range 100 {
-		wg.Add(1)
-		go func() {
-			defer wg.Done()
+		wg.Go(func() {
 			clientSession, err := client.Connect(ctx, &StreamableClientTransport{Endpoint: httpServer.URL}, nil)
 			if err != nil {
 				t.Errorf("Connect failed: %v", err)
@@ -287,7 +283,7 @@ func TestStreamableConcurrentHandling(t *testing.T) {
 					t.Errorf("got count %d, want %d", got, i)
 				}
 			}
-		}()
+		})
 	}
 	wg.Wait()
 }
@@ -1293,9 +1289,7 @@ func testStreamableHandler(t *testing.T, handler http.Handler, requests []stream
 		ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
 
 		var wg sync.WaitGroup
-		wg.Add(1)
-		go func() {
-			defer wg.Done()
+		wg.Go(func() {
 
 			for m := range out {
 				if req, ok := m.(*jsonrpc.Request); ok && req.IsCall() {
@@ -1315,7 +1309,7 @@ func testStreamableHandler(t *testing.T, handler http.Handler, requests []stream
 					cancel()
 				}
 			}
-		}()
+		})
 
 		gotSessionID, gotStatusCode, gotBody, err := request.do(ctx, httpServer.URL, sessionID.Load().(string), out)
 
@@ -1353,11 +1347,9 @@ func testStreamableHandler(t *testing.T, handler http.Handler, requests []stream
 	var wg sync.WaitGroup
 	for i, request := range requests {
 		if request.async || request.onRequest > 0 {
-			wg.Add(1)
-			go func() {
-				defer wg.Done()
+			wg.Go(func() {
 				doStep(t, i, request)
-			}()
+			})
 		} else {
 			doStep(t, i, request)
 		}
@@ -2071,18 +2063,15 @@ func TestStreamableSessionTimeout(t *testing.T) {
 	// Spin up two goroutines, each making a request every 10ms. These requests
 	// should keep the server from timing out.
 	var wg sync.WaitGroup
-	wg.Add(2)
 	for range 2 {
-		go func() {
-			defer wg.Done()
-
+		wg.Go(func() {
 			for range 20 {
 				if _, err := session.ListTools(ctx, nil); err != nil {
 					t.Errorf("ListTools failed: %v", err)
 				}
 				time.Sleep(10 * time.Millisecond)
 			}
-		}()
+		})
 	}
 
 	wg.Wait()
@@ -2154,8 +2143,7 @@ data: keepalive
 	}
 
 	// Create a minimal streamableClientConn for testing
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
+	ctx := t.Context()
 
 	incoming := make(chan jsonrpc.Message, 10)
 	done := make(chan struct{})