github.com/blend/go-sdk@v1.20240719.1/datadog/rate_sampler_test.go (about)

     1  /*
     2  
     3  Copyright (c) 2024 - Present. Blend Labs, Inc. All rights reserved
     4  Use of this source code is governed by a MIT license that can be found in the LICENSE file.
     5  
     6  */
     7  
     8  package datadog
     9  
    10  import (
    11  	"fmt"
    12  	"testing"
    13  
    14  	"github.com/blend/go-sdk/assert"
    15  )
    16  
    17  func Test_RateSampler(t *testing.T) {
    18  	assert := assert.New(t)
    19  
    20  	// 25% sample (25% pass at infinity)
    21  	sampler := RateSampler(0.25)
    22  
    23  	var passed int
    24  	for x := 0; x < 102400; x++ {
    25  		if sampler.Sample(nil) {
    26  			passed++
    27  		}
    28  	}
    29  
    30  	// Since we are sampling incrementally, we cannot guarantee that we would
    31  	// sample exactly 25% of the population, so we add a buffer here to account
    32  	// for the errors. The ratio of errors gets smaller the larger the population.
    33  	expected := int(102400 * 0.25)
    34  	buffer := 1024
    35  	assert.True(passed > expected-buffer, fmt.Sprint(passed))
    36  	assert.True(passed < expected+buffer, fmt.Sprint(passed))
    37  }
    38  
    39  func Test_RateSampler_FullOn(t *testing.T) {
    40  	assert := assert.New(t)
    41  
    42  	// 100% sample (all pass)
    43  	sampler := RateSampler(1)
    44  
    45  	var passed int
    46  	for x := 0; x < 1024; x++ {
    47  		if sampler.Sample(nil) {
    48  			passed++
    49  		}
    50  	}
    51  	assert.Equal(passed, 1024)
    52  }
    53  
    54  func Test_RateSampler_FullOff(t *testing.T) {
    55  	assert := assert.New(t)
    56  
    57  	// 0% sample (none passes)
    58  	sampler := RateSampler(0)
    59  
    60  	var passed int
    61  	for x := 0; x < 1024; x++ {
    62  		if sampler.Sample(nil) {
    63  			passed++
    64  		}
    65  	}
    66  	assert.Zero(passed)
    67  }
    68  
    69  func Test_RateSampler_FullOff_Negative(t *testing.T) {
    70  	assert := assert.New(t)
    71  
    72  	// Negative sampling rate (none passes)
    73  	sampler := RateSampler(-1)
    74  
    75  	var passed int
    76  	for x := 0; x < 1024; x++ {
    77  		if sampler.Sample(nil) {
    78  			passed++
    79  		}
    80  	}
    81  	assert.Zero(passed)
    82  }