label_test.go

     1  // Copyright 2017 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 pprof
     6  
     7  import (
     8  	"context"
     9  	"reflect"
    10  	"sort"
    11  	"testing"
    12  )
    13  
    14  func labelsSorted(ctx context.Context) []label {
    15  	ls := []label{}
    16  	ForLabels(ctx, func(key, value string) bool {
    17  		ls = append(ls, label{key, value})
    18  		return true
    19  	})
    20  	sort.Sort(labelSorter(ls))
    21  	return ls
    22  }
    23  
    24  type labelSorter []label
    25  
    26  func (s labelSorter) Len() int           { return len(s) }
    27  func (s labelSorter) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
    28  func (s labelSorter) Less(i, j int) bool { return s[i].key < s[j].key }
    29  
    30  func TestContextLabels(t *testing.T) {
    31  	// Background context starts with no labels.
    32  	ctx := context.Background()
    33  	labels := labelsSorted(ctx)
    34  	if len(labels) != 0 {
    35  		t.Errorf("labels on background context: want [], got %v ", labels)
    36  	}
    37  
    38  	// Add a single label.
    39  	ctx = WithLabels(ctx, Labels("key", "value"))
    40  	// Retrieve it with Label.
    41  	v, ok := Label(ctx, "key")
    42  	if !ok || v != "value" {
    43  		t.Errorf(`Label(ctx, "key"): got %v, %v; want "value", ok`, v, ok)
    44  	}
    45  	gotLabels := labelsSorted(ctx)
    46  	wantLabels := []label{{"key", "value"}}
    47  	if !reflect.DeepEqual(gotLabels, wantLabels) {
    48  		t.Errorf("(sorted) labels on context: got %v, want %v", gotLabels, wantLabels)
    49  	}
    50  
    51  	// Add a label with a different key.
    52  	ctx = WithLabels(ctx, Labels("key2", "value2"))
    53  	v, ok = Label(ctx, "key2")
    54  	if !ok || v != "value2" {
    55  		t.Errorf(`Label(ctx, "key2"): got %v, %v; want "value2", ok`, v, ok)
    56  	}
    57  	gotLabels = labelsSorted(ctx)
    58  	wantLabels = []label{{"key", "value"}, {"key2", "value2"}}
    59  	if !reflect.DeepEqual(gotLabels, wantLabels) {
    60  		t.Errorf("(sorted) labels on context: got %v, want %v", gotLabels, wantLabels)
    61  	}
    62  
    63  	// Add label with first key to test label replacement.
    64  	ctx = WithLabels(ctx, Labels("key", "value3"))
    65  	v, ok = Label(ctx, "key")
    66  	if !ok || v != "value3" {
    67  		t.Errorf(`Label(ctx, "key3"): got %v, %v; want "value3", ok`, v, ok)
    68  	}
    69  	gotLabels = labelsSorted(ctx)
    70  	wantLabels = []label{{"key", "value3"}, {"key2", "value2"}}
    71  	if !reflect.DeepEqual(gotLabels, wantLabels) {
    72  		t.Errorf("(sorted) labels on context: got %v, want %v", gotLabels, wantLabels)
    73  	}
    74  
    75  	// Labels called with two labels with the same key should pick the second.
    76  	ctx = WithLabels(ctx, Labels("key4", "value4a", "key4", "value4b"))
    77  	v, ok = Label(ctx, "key4")
    78  	if !ok || v != "value4b" {
    79  		t.Errorf(`Label(ctx, "key4"): got %v, %v; want "value4b", ok`, v, ok)
    80  	}
    81  	gotLabels = labelsSorted(ctx)
    82  	wantLabels = []label{{"key", "value3"}, {"key2", "value2"}, {"key4", "value4b"}}
    83  	if !reflect.DeepEqual(gotLabels, wantLabels) {
    84  		t.Errorf("(sorted) labels on context: got %v, want %v", gotLabels, wantLabels)
    85  	}
    86  }
    87  
    88  func TestLabelMapStringer(t *testing.T) {
    89  	for _, tbl := range []struct {
    90  		m        labelMap
    91  		expected string
    92  	}{
    93  		{
    94  			m: labelMap{
    95  				// empty map
    96  			},
    97  			expected: "{}",
    98  		}, {
    99  			m: labelMap{
   100  				"foo": "bar",
   101  			},
   102  			expected: `{"foo":"bar"}`,
   103  		}, {
   104  			m: labelMap{
   105  				"foo":             "bar",
   106  				"key1":            "value1",
   107  				"key2":            "value2",
   108  				"key3":            "value3",
   109  				"key4WithNewline": "\nvalue4",
   110  			},
   111  			expected: `{"foo":"bar", "key1":"value1", "key2":"value2", "key3":"value3", "key4WithNewline":"\nvalue4"}`,
   112  		},
   113  	} {
   114  		if got := tbl.m.String(); tbl.expected != got {
   115  			t.Errorf("%#v.String() = %q; want %q", tbl.m, got, tbl.expected)
   116  		}
   117  	}
   118  }
   119
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