test: use T.TempDir to create temporary test directory (#2710)

This commit replaces `ioutil.TempDir` with `t.TempDir` in tests. The
directory created by `t.TempDir` is automatically removed when the test
and all its subtests complete.

Prior to this commit, temporary directory created using `ioutil.TempDir`
needs to be removed manually by calling `os.RemoveAll`, which is omitted
in some tests. The error handling boilerplate e.g.
	defer func() {
		if err := os.RemoveAll(dir); err != nil {
			t.Fatal(err)
		}
	}
is also tedious, but `t.TempDir` handles this for us nicely.

Reference: https://pkg.go.dev/testing#T.TempDir
Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>

Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>

cmd/kapacitord/run/command_test.go

@@ -13,11 +13,7 @@ import (
 )
 
 func TestCommand_PIDFile(t *testing.T) {
-	tmpdir, err := ioutil.TempDir(os.TempDir(), "kapacitord-test")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer os.RemoveAll(tmpdir)
+	tmpdir := t.TempDir()
 
 	// Write out a config file that does not attempt to connect to influxdb.
 	configFile := filepath.Join(tmpdir, "kapacitor.conf")

integrations/streamer_test.go

@@ -10602,11 +10602,7 @@ stream
 }
 
 func TestStream_AlertLog(t *testing.T) {
-	tmpDir, err := ioutil.TempDir("", "TestStream_AlertLog")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer os.RemoveAll(tmpDir)
+	tmpDir := t.TempDir()
 	normalPath := filepath.Join(tmpDir, "normal.log")
 	modePath := filepath.Join(tmpDir, "mode.log")
 

server/server_helper_test.go

@@ -78,15 +78,15 @@ func (s *Server) Restart() {
 }
 
 // OpenServer opens a test server.
-func OpenDefaultServer() (*Server, *client.Client) {
-	c := NewConfig()
+func OpenDefaultServer(t *testing.T) (*Server, *client.Client) {
+	c := NewConfig(t)
 	s := OpenServer(c)
 	client := Client(s)
 	return s, client
 }
 
-func OpenLoadServer() (*Server, *server.Config, *client.Client) {
-	c := NewConfig()
+func OpenLoadServer(t *testing.T) (*Server, *server.Config, *client.Client) {
+	c := NewConfig(t)
 	if err := copyFiles("testdata/load", c.Load.Dir); err != nil {
 		panic(err)
 	}
@@ -260,31 +260,23 @@ func (s *Server) Stats() (stats, error) {
 }
 
 // NewConfig returns the default config with temporary paths.
-func NewConfig() *server.Config {
+func NewConfig(t *testing.T) *server.Config {
 	c := server.NewConfig()
 	c.MQTT = mqtt.Configs{}
 	c.Slack = slack.Configs{slack.NewConfig()}
 	c.Reporting.Enabled = false
-	c.Replay.Dir = MustTempDir()
-	c.Storage.BoltDBPath = filepath.Join(MustTempDir(), "bolt.db")
-	c.DataDir = MustTempDir()
+	c.Replay.Dir = t.TempDir()
+	c.Storage.BoltDBPath = filepath.Join(t.TempDir(), "bolt.db")
+	c.DataDir = t.TempDir()
 	c.HTTP.BindAddress = "127.0.0.1:0"
 	//c.HTTP.BindAddress = "127.0.0.1:9092"
 	//c.HTTP.GZIP = false
 	c.InfluxDB[0].Enabled = false
 	c.Load.Enabled = true
-	c.Load.Dir = MustTempDir()
+	c.Load.Dir = t.TempDir()
 	return c
 }
 
-func MustTempDir() string {
-	d, err := ioutil.TempDir("", "kapacitord-")
-	if err != nil {
-		panic(err)
-	}
-	return d
-}
-
 func configureLogging() {
 	if testing.Verbose() {
 		wlog.SetLevel(wlog.DEBUG)