github.com/twelsh-aw/go/src@v0.0.0-20230516233729-a56fe86a7c81/internal/godebug/godebug_test.go (about)

     1  // Copyright 2021 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package godebug_test
     6  
     7  import (
     8  	"fmt"
     9  	. "internal/godebug"
    10  	"internal/testenv"
    11  	"os"
    12  	"os/exec"
    13  	"reflect"
    14  	"runtime/metrics"
    15  	"sort"
    16  	"strings"
    17  	"testing"
    18  )
    19  
    20  func TestGet(t *testing.T) {
    21  	foo := New("#foo")
    22  	tests := []struct {
    23  		godebug string
    24  		setting *Setting
    25  		want    string
    26  	}{
    27  		{"", New("#"), ""},
    28  		{"", foo, ""},
    29  		{"foo=bar", foo, "bar"},
    30  		{"foo=bar,after=x", foo, "bar"},
    31  		{"before=x,foo=bar,after=x", foo, "bar"},
    32  		{"before=x,foo=bar", foo, "bar"},
    33  		{",,,foo=bar,,,", foo, "bar"},
    34  		{"foodecoy=wrong,foo=bar", foo, "bar"},
    35  		{"foo=", foo, ""},
    36  		{"foo", foo, ""},
    37  		{",foo", foo, ""},
    38  		{"foo=bar,baz", New("#loooooooong"), ""},
    39  	}
    40  	for _, tt := range tests {
    41  		t.Setenv("GODEBUG", tt.godebug)
    42  		got := tt.setting.Value()
    43  		if got != tt.want {
    44  			t.Errorf("get(%q, %q) = %q; want %q", tt.godebug, tt.setting.Name(), got, tt.want)
    45  		}
    46  	}
    47  }
    48  
    49  func TestMetrics(t *testing.T) {
    50  	const name = "http2client" // must be a real name so runtime will accept it
    51  
    52  	var m [1]metrics.Sample
    53  	m[0].Name = "/godebug/non-default-behavior/" + name + ":events"
    54  	metrics.Read(m[:])
    55  	if kind := m[0].Value.Kind(); kind != metrics.KindUint64 {
    56  		t.Fatalf("NonDefault kind = %v, want uint64", kind)
    57  	}
    58  
    59  	s := New(name)
    60  	s.Value()
    61  	s.IncNonDefault()
    62  	s.IncNonDefault()
    63  	s.IncNonDefault()
    64  	metrics.Read(m[:])
    65  	if kind := m[0].Value.Kind(); kind != metrics.KindUint64 {
    66  		t.Fatalf("NonDefault kind = %v, want uint64", kind)
    67  	}
    68  	if count := m[0].Value.Uint64(); count != 3 {
    69  		t.Fatalf("NonDefault value = %d, want 3", count)
    70  	}
    71  }
    72  
    73  func TestCmdBisect(t *testing.T) {
    74  	testenv.MustHaveGoBuild(t)
    75  	out, err := exec.Command("go", "run", "cmd/vendor/golang.org/x/tools/cmd/bisect", "GODEBUG=buggy=1#PATTERN", os.Args[0], "-test.run=BisectTestCase").CombinedOutput()
    76  	if err != nil {
    77  		t.Fatalf("exec bisect: %v\n%s", err, out)
    78  	}
    79  
    80  	var want []string
    81  	src, err := os.ReadFile("godebug_test.go")
    82  	for i, line := range strings.Split(string(src), "\n") {
    83  		if strings.Contains(line, "BISECT"+" "+"BUG") {
    84  			want = append(want, fmt.Sprintf("godebug_test.go:%d", i+1))
    85  		}
    86  	}
    87  	sort.Strings(want)
    88  
    89  	var have []string
    90  	for _, line := range strings.Split(string(out), "\n") {
    91  		if strings.Contains(line, "godebug_test.go:") {
    92  			have = append(have, line[strings.LastIndex(line, "godebug_test.go:"):])
    93  		}
    94  	}
    95  	sort.Strings(have)
    96  
    97  	if !reflect.DeepEqual(have, want) {
    98  		t.Errorf("bad bisect output:\nhave %v\nwant %v\ncomplete output:\n%s", have, want, string(out))
    99  	}
   100  }
   101  
   102  // This test does nothing by itself, but you can run
   103  //
   104  //	bisect 'GODEBUG=buggy=1#PATTERN' go test -run=BisectTestCase
   105  //
   106  // to see that the GODEBUG bisect support is working.
   107  // TestCmdBisect above does exactly that.
   108  func TestBisectTestCase(t *testing.T) {
   109  	s := New("#buggy")
   110  	for i := 0; i < 10; i++ {
   111  		a := s.Value() == "1"
   112  		b := s.Value() == "1"
   113  		c := s.Value() == "1" // BISECT BUG
   114  		d := s.Value() == "1" // BISECT BUG
   115  		e := s.Value() == "1" // BISECT BUG
   116  
   117  		if a {
   118  			t.Log("ok")
   119  		}
   120  		if b {
   121  			t.Log("ok")
   122  		}
   123  		if c {
   124  			t.Error("bug")
   125  		}
   126  		if d &&
   127  			e {
   128  			t.Error("bug")
   129  		}
   130  	}
   131  }