Fix errcheck warnings

Signed-off-by: z1cheng <imchench@gmail.com>

pkg/util/file/file_test.go

@@ -35,8 +35,12 @@ func TestSHA1(t *testing.T) {
 		if err != nil {
 			t.Fatal(err)
 		}
-		f.Write(test.content)
-		f.Sync()
+		if _, err := f.Write(test.content); err != nil {
+			t.Error(err)
+		}
+		if err := f.Sync(); err != nil {
+			t.Error(err)
+		}
 
 		sha := SHA1(f.Name())
 		f.Close()

pkg/util/file/file_watcher_test.go

@@ -59,7 +59,9 @@ func TestFileWatcher(t *testing.T) {
 		t.Fatalf("expected no events before writing a file")
 	case <-timeoutChan:
 	}
-	os.WriteFile(f.Name(), []byte{}, ReadWriteByUser)
+	if err := os.WriteFile(f.Name(), []byte{}, ReadWriteByUser); err != nil {
+		t.Errorf("unexpected error: %v", err)
+	}
 	select {
 	case <-events:
 	case <-timeoutChan:

pkg/util/process/sigterm_test.go

@@ -42,9 +42,9 @@ func (f *FakeProcess) exiterFunc(code int) {
 	f.exitCode = code
 }
 
-func sendDelayedSignal(delay time.Duration) {
+func sendDelayedSignal(delay time.Duration) error {
 	time.Sleep(delay * time.Second)
-	syscall.Kill(syscall.Getpid(), syscall.SIGTERM)
+	return syscall.Kill(syscall.Getpid(), syscall.SIGTERM)
 }
 
 func TestHandleSigterm(t *testing.T) {
@@ -66,7 +66,12 @@ func TestHandleSigterm(t *testing.T) {
 	for _, tt := range tests {
 		process := &FakeProcess{shouldError: tt.shouldError}
 		t.Run(tt.name, func(t *testing.T) {
-			go sendDelayedSignal(2) // Send a signal after 2 seconds
+			go func() {
+				err := sendDelayedSignal(2) // Send a signal after 2 seconds
+				if err != nil {
+					t.Errorf("error sending delayed signal: %v", err)
+				}
+			}()
 			HandleSigterm(process, tt.delay, process.exiterFunc)
 		})
 		if tt.shouldError && process.exitCode != 1 {