libgo/go/runtime/pprof/label_test.go

   1 package pprof
   2
   3 import (
   4         "context"
   5         "reflect"
   6         "sort"
   7         "testing"
   8 )
   9
  10 func labelsSorted(ctx context.Context) []label {
  11         ls := []label{}
  12         ForLabels(ctx, func(key, value string) bool {
  13                 ls = append(ls, label{key, value})
  14                 return true
  15         })
  16         sort.Sort(labelSorter(ls))
  17         return ls
  18 }
  19
  20 type labelSorter []label
  21
  22 func (s labelSorter) Len() int           { return len(s) }
  23 func (s labelSorter) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
  24 func (s labelSorter) Less(i, j int) bool { return s[i].key < s[j].key }
  25
  26 func TestContextLabels(t *testing.T) {
  27         // Background context starts with no lablels.
  28         ctx := context.Background()
  29         labels := labelsSorted(ctx)
  30         if len(labels) != 0 {
  31                 t.Errorf("labels on background context: want [], got %v ", labels)
  32         }
  33
  34         // Add a single label.
  35         ctx = WithLabels(ctx, Labels("key", "value"))
  36         // Retrieve it with Label.
  37         v, ok := Label(ctx, "key")
  38         if !ok || v != "value" {
  39                 t.Errorf(`Label(ctx, "key"): got %v, %v; want "value", ok`, v, ok)
  40         }
  41         gotLabels := labelsSorted(ctx)
  42         wantLabels := []label{{"key", "value"}}
  43         if !reflect.DeepEqual(gotLabels, wantLabels) {
  44                 t.Errorf("(sorted) labels on context: got %v, want %v", gotLabels, wantLabels)
  45         }
  46
  47         // Add a label with a different key.
  48         ctx = WithLabels(ctx, Labels("key2", "value2"))
  49         v, ok = Label(ctx, "key2")
  50         if !ok || v != "value2" {
  51                 t.Errorf(`Label(ctx, "key2"): got %v, %v; want "value2", ok`, v, ok)
  52         }
  53         gotLabels = labelsSorted(ctx)
  54         wantLabels = []label{{"key", "value"}, {"key2", "value2"}}
  55         if !reflect.DeepEqual(gotLabels, wantLabels) {
  56                 t.Errorf("(sorted) labels on context: got %v, want %v", gotLabels, wantLabels)
  57         }
  58
  59         // Add label with first key to test label replacement.
  60         ctx = WithLabels(ctx, Labels("key", "value3"))
  61         v, ok = Label(ctx, "key")
  62         if !ok || v != "value3" {
  63                 t.Errorf(`Label(ctx, "key3"): got %v, %v; want "value3", ok`, v, ok)
  64         }
  65         gotLabels = labelsSorted(ctx)
  66         wantLabels = []label{{"key", "value3"}, {"key2", "value2"}}
  67         if !reflect.DeepEqual(gotLabels, wantLabels) {
  68                 t.Errorf("(sorted) labels on context: got %v, want %v", gotLabels, wantLabels)
  69         }
  70
  71         // Labels called with two labels with the same key should pick the second.
  72         ctx = WithLabels(ctx, Labels("key4", "value4a", "key4", "value4b"))
  73         v, ok = Label(ctx, "key4")
  74         if !ok || v != "value4b" {
  75                 t.Errorf(`Label(ctx, "key4"): got %v, %v; want "value4b", ok`, v, ok)
  76         }
  77         gotLabels = labelsSorted(ctx)
  78         wantLabels = []label{{"key", "value3"}, {"key2", "value2"}, {"key4", "value4b"}}
  79         if !reflect.DeepEqual(gotLabels, wantLabels) {
  80                 t.Errorf("(sorted) labels on context: got %v, want %v", gotLabels, wantLabels)
  81         }
  82 }