chore: add more tests (#3338)

core/proc/goroutines+polyfill.go

@@ -1,6 +0,0 @@
-//go:build windows
-
-package proc
-
-func dumpGoroutines() {
-}

core/proc/goroutines.go

@@ -18,7 +18,11 @@ const (
 	debugLevel       = 2
 )
 
-func dumpGoroutines() {
+type creator interface {
+	Create(name string) (file *os.File, err error)
+}
+
+func dumpGoroutines(ctor creator) {
 	command := path.Base(os.Args[0])
 	pid := syscall.Getpid()
 	dumpFile := path.Join(os.TempDir(), fmt.Sprintf("%s-%d-goroutines-%s.dump",
@@ -26,10 +30,16 @@ func dumpGoroutines() {
 
 	logx.Infof("Got dump goroutine signal, printing goroutine profile to %s", dumpFile)
 
-	if f, err := os.Create(dumpFile); err != nil {
+	if f, err := ctor.Create(dumpFile); err != nil {
 		logx.Errorf("Failed to dump goroutine profile, error: %v", err)
 	} else {
 		defer f.Close()
 		pprof.Lookup(goroutineProfile).WriteTo(f, debugLevel)
 	}
 }
+
+type fileCreator struct{}
+
+func (fc fileCreator) Create(name string) (file *os.File, err error) {
+	return os.Create(name)
+}

core/proc/goroutines_test.go

@@ -1,6 +1,10 @@
+//go:build linux || darwin
+
 package proc
 
 import (
+	"errors"
+	"os"
 	"strings"
 	"testing"
 
@@ -9,7 +13,29 @@ import (
 )
 
 func TestDumpGoroutines(t *testing.T) {
-	buf := logtest.NewCollector(t)
-	dumpGoroutines()
-	assert.True(t, strings.Contains(buf.String(), ".dump"))
+	t.Run("real file", func(t *testing.T) {
+		buf := logtest.NewCollector(t)
+		dumpGoroutines(fileCreator{})
+		assert.True(t, strings.Contains(buf.String(), ".dump"))
+	})
+
+	t.Run("fake file", func(t *testing.T) {
+		const msg = "any message"
+		buf := logtest.NewCollector(t)
+		err := errors.New(msg)
+		dumpGoroutines(fakeCreator{
+			file: &os.File{},
+			err:  err,
+		})
+		assert.True(t, strings.Contains(buf.String(), msg))
+	})
+}
+
+type fakeCreator struct {
+	file *os.File
+	err  error
+}
+
+func (fc fakeCreator) Create(name string) (file *os.File, err error) {
+	return fc.file, fc.err
 }

core/proc/signals.go

@@ -26,7 +26,7 @@ func init() {
 			v := <-signals
 			switch v {
 			case syscall.SIGUSR1:
-				dumpGoroutines()
+				dumpGoroutines(fileCreator{})
 			case syscall.SIGUSR2:
 				if profiler == nil {
 					profiler = StartProfile()

core/proc/signals_test.go

@@ -1,3 +1,5 @@
+//go:build linux || darwin
+
 package proc
 
 import (