From 8ecee476f6ae1a1ae7a09b86187dc7d3f7759c61 Mon Sep 17 00:00:00 2001
From: Brad Fitzpatrick <bradfitz@tailscale.com>
Date: Fri, 4 Sep 2020 08:36:07 -0700
Subject: [PATCH] ipn: simplify TestLocalLogLines, defer a Shutdown of its
 LocalBackend

The test's LocalBackend was not shut down (Shutdown both releases
resources and waits for its various goroutines to end). This should
fix the test race we were seeing. It definitely fixes the file
descriptor leak that preventing -race -count=500 from passing before.
---
 ipn/loglines_test.go | 32 +++++++-------------------------
 1 file changed, 7 insertions(+), 25 deletions(-)

diff --git a/ipn/loglines_test.go b/ipn/loglines_test.go
index 5f317e5de..5e6519151 100644
--- a/ipn/loglines_test.go
+++ b/ipn/loglines_test.go
@@ -5,6 +5,7 @@
 package ipn
 
 import (
+	"reflect"
 	"testing"
 	"time"
 
@@ -48,6 +49,7 @@ func TestLocalLogLines(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
+	defer lb.Shutdown()
 
 	// custom adjustments for required non-nil fields
 	lb.prefs = NewPrefs()
@@ -55,30 +57,10 @@ func TestLocalLogLines(t *testing.T) {
 	// hacky manual override of the usual log-on-change behaviour of keylogf
 	lb.keyLogf = logListen.Logf
 
-	// testing infrastructure
-	type linesTest struct {
-		name string
-		want []string
-	}
-
-	tests := []linesTest{
-		{
-			name: "after prefs",
-			want: []string{
-				"peer keys: %s",
-				"v%v peers: %v",
-			},
-		},
-		{
-			name: "after peers",
-			want: []string{},
-		},
-	}
-
-	testLogs := func(want linesTest) func(t *testing.T) {
+	testWantRemain := func(wantRemain ...string) func(t *testing.T) {
 		return func(t *testing.T) {
-			if linesLeft := logListen.Check(); len(linesLeft) != len(want.want) {
-				t.Errorf("got %v, expected %v", linesLeft, want)
+			if remain := logListen.Check(); !reflect.DeepEqual(remain, wantRemain) {
+				t.Errorf("remain %q, want %q", remain, wantRemain)
 			}
 		}
 	}
@@ -89,7 +71,7 @@ func TestLocalLogLines(t *testing.T) {
 	prefs.Persist = persist
 	lb.SetPrefs(prefs)
 
-	t.Run(tests[0].name, testLogs(tests[0]))
+	t.Run("after_prefs", testWantRemain("peer keys: %s", "v%v peers: %v"))
 
 	// log peers, peer keys
 	status := &wgengine.Status{
@@ -103,5 +85,5 @@ func TestLocalLogLines(t *testing.T) {
 	}
 	lb.parseWgStatus(status)
 
-	t.Run(tests[1].name, testLogs(tests[1]))
+	t.Run("after_peers", testWantRemain())
 }