github.com/m3db/m3@v1.5.0/src/x/sampler/sampler_test.go (about)

     1  // Copyright (c) 2018 Uber Technologies, Inc.
     2  //
     3  // Permission is hereby granted, free of charge, to any person obtaining a copy
     4  // of this software and associated documentation files (the "Software"), to deal
     5  // in the Software without restriction, including without limitation the rights
     6  // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
     7  // copies of the Software, and to permit persons to whom the Software is
     8  // furnished to do so, subject to the following conditions:
     9  //
    10  // The above copyright notice and this permission notice shall be included in
    11  // all copies or substantial portions of the Software.
    12  //
    13  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    14  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    15  // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    16  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    17  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    18  // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
    19  // THE SOFTWARE.
    20  
    21  package sampler
    22  
    23  import (
    24  	"testing"
    25  
    26  	"github.com/stretchr/testify/assert"
    27  	"github.com/stretchr/testify/require"
    28  	"gopkg.in/yaml.v2"
    29  )
    30  
    31  func TestInvalidSampleRate(t *testing.T) {
    32  	_, err := NewSampler(-1.0)
    33  	require.Error(t, err)
    34  
    35  	_, err = NewSampler(0.0)
    36  	require.NoError(t, err)
    37  
    38  	_, err = NewSampler(1.0)
    39  	require.NoError(t, err)
    40  
    41  	_, err = NewSampler(2.0)
    42  	require.Error(t, err)
    43  }
    44  
    45  func TestSampler(t *testing.T) {
    46  	s, err := NewSampler(0.5)
    47  	require.NoError(t, err)
    48  	require.True(t, s.Sample())
    49  	require.False(t, s.Sample())
    50  	require.True(t, s.Sample())
    51  	require.False(t, s.Sample())
    52  	require.True(t, s.Sample())
    53  
    54  	s, err = NewSampler(0.25)
    55  	require.NoError(t, err)
    56  	require.True(t, s.Sample())
    57  	require.False(t, s.Sample())
    58  	require.False(t, s.Sample())
    59  	require.False(t, s.Sample())
    60  	require.True(t, s.Sample())
    61  	require.False(t, s.Sample())
    62  	require.False(t, s.Sample())
    63  	require.False(t, s.Sample())
    64  	require.True(t, s.Sample())
    65  }
    66  
    67  func TestRateUnmarshalYAML(t *testing.T) {
    68  	type config struct {
    69  		Rate Rate `yaml:"rate"`
    70  	}
    71  
    72  	tests := []struct {
    73  		input       []byte
    74  		expectValue float64
    75  		expectErr   bool
    76  	}{
    77  		{
    78  			input:       []byte("rate: foo\n"),
    79  			expectValue: 0,
    80  			expectErr:   true,
    81  		},
    82  		{
    83  			input:       []byte("rate: -1\n"),
    84  			expectValue: 0,
    85  			expectErr:   true,
    86  		},
    87  		{
    88  			input:       []byte("\n"),
    89  			expectValue: 0,
    90  			expectErr:   false,
    91  		},
    92  		{
    93  			input:       []byte("rate: 0\n"),
    94  			expectValue: 0,
    95  			expectErr:   false,
    96  		},
    97  		{
    98  			input:       []byte("rate: 1\n"),
    99  			expectValue: 1,
   100  			expectErr:   false,
   101  		},
   102  		{
   103  			input:       []byte("rate: 1.01\n"),
   104  			expectValue: 0,
   105  			expectErr:   true,
   106  		},
   107  	}
   108  
   109  	for _, test := range tests {
   110  		t.Run(string(test.input), func(t *testing.T) {
   111  			var c config
   112  			err := yaml.Unmarshal(test.input, &c)
   113  			if test.expectErr {
   114  				require.Error(t, err)
   115  			} else {
   116  				require.NoError(t, err)
   117  			}
   118  
   119  			assert.Equal(t, test.expectValue, c.Rate.Value())
   120  		})
   121  	}
   122  }