test: cleanup goroutines at end of test (#1084)

Close test instances at the end of the test so that the do not leak beyond the end of the test. This will allow goroutine leak detection to work and will allow these tests to be wrapped in a synctest time bubble in the future.

Author: gammazero

bitswap/bitswap_test.go

@@ -332,6 +332,13 @@ func PerformDistributionTest(t *testing.T, numInstances, numBlocks int) {
 			t.Fatal(err)
 		}
 	}
+
+	for _, inst := range instances {
+		err := inst.Exchange.Close()
+		if err != nil {
+			t.Fatal(err)
+		}
+	}
 }
 
 // TODO simplify this test. get to the _essence_!
@@ -375,6 +382,13 @@ func TestSendToWantingPeer(t *testing.T) {
 	if !blkrecvd.Cid().Equals(alpha.Cid()) {
 		t.Fatal("Wrong block!")
 	}
+
+	for _, inst := range peers {
+		err := inst.Exchange.Close()
+		if err != nil {
+			t.Fatal(err)
+		}
+	}
 }
 
 func TestEmptyKey(t *testing.T) {
@@ -391,6 +405,10 @@ func TestEmptyKey(t *testing.T) {
 	if !ipld.IsNotFound(err) {
 		t.Error("empty string key should return ErrNotFound")
 	}
+
+	if err = bs.Close(); err != nil {
+		t.Fatal(err)
+	}
 }
 
 func assertStat(t *testing.T, st *bitswap.Stat, sblks, rblks, sdata, rdata uint64) {
@@ -557,6 +575,8 @@ func TestWantlistCleanup(t *testing.T) {
 	instances := ig.Instances(2)
 	instance := instances[0]
 	bswap := instance.Exchange
+	defer bswap.Close()
+	defer instances[1].Exchange.Close()
 	blocks := random.BlocksOfSize(20, blockSize)
 
 	var keys []cid.Cid