Remove test temporary directories when finished

They're all grouped together in a parent directory that gets removed. Testing with mmap storage can generate very large files on bad filesystems.

client_test.go

@@ -6,7 +6,6 @@ import (
 	"fmt"
 	"io"
 	"io/ioutil"
-	"log"
 	"math/rand"
 	"net"
 	"os"
@@ -32,23 +31,19 @@ import (
 	"github.com/anacrolix/torrent/storage"
 )
 
-func init() {
-	log.SetFlags(log.LstdFlags | log.Llongfile)
-}
-
 func TestingConfig() *Config {
 	return &Config{
-		ListenAddr:      "localhost:0",
-		NoDHT:           true,
-		DisableTrackers: true,
+		ListenAddr: "localhost:0",
+		NoDHT:      true,
 		DataDir: func() string {
-			ret, err := ioutil.TempDir("", "")
+			ret, err := ioutil.TempDir(tempDir, "")
 			if err != nil {
 				panic(err)
 			}
 			return ret
 		}(),
-		Debug: true,
+		DisableTrackers: true,
+		Debug:           true,
 	}
 }
 

main_test.go

@@ -1,12 +1,26 @@
 package torrent
 
 import (
+	"io/ioutil"
+	"log"
 	"os"
 	"testing"
 )
 
+var tempDir string
+
+func init() {
+	log.SetFlags(log.LstdFlags | log.Llongfile)
+	var err error
+	tempDir, err = ioutil.TempDir("", "torrent.test")
+	if err != nil {
+		panic(err)
+	}
+}
+
 func TestMain(m *testing.M) {
 	code := m.Run()
+	os.RemoveAll(tempDir)
 	// select {}
 	os.Exit(code)
 }