Unit test with go

  • brief introduction
  • unit testing
  • performance testing
  • performance analysis
  • Test coverage
  • summary
  • Code of current part

brief introduction

In daily development, testing is indispensable

One of the go standard libraries is calledtestingIt can be used in unit test and performance test
It’s a commandgo testIntegrated

Test files are suffixed with_test.goNamed, usually in the same package as the file being tested

unit testing

The format of unit test is as follows:

func TestAbs(t *testing.T) {
  got := Abs(-1)
  if got != 1 {
    t.Errorf("Abs(-1) = %d; want 1", got)

stayutilCreate a file in the directoryutil_test.go, add a unit test:

package util

import "testing"

//Common test
func TestGenShortID(t *testing.T) {
    shortID, err := GenShortID()
    if shortID == "" || err != nil {
        t.Error("GenShortID failed")

Then, run it in the root directorygo test -v ./util/, the test results are as follows:

[email protected]:/workspace# go test -v ./util/
=== RUN   TestGenShortID
--- PASS: TestGenShortID (0.00s)
ok      tzh.com/web/util        0.006s

performance testing

The results of performance test are as follows:

func BenchmarkHello(b *testing.B) {
  for i := 0; i < b.N; i++ {

stayutil_test.goAdd performance test:

//Performance test
func BenchmarkGenShortID(b *testing.B) {
    for i := 0; i < b.N; i++ {

The results are as follows (using--run=noneAvoid running normal test functions because there is usually no match for function namesnone):

[email protected]:/workspace# go test -v -bench="BenchmarkGenShortID$" --run=none ./util/
goos: linux
goarch: amd64
pkg: tzh.com/web/util
BenchmarkGenShortID-2             507237              2352 ns/op
ok      tzh.com/web/util        1.229s

This means that the average operationGenShortID()It takes 2352 nanoseconds

performance analysis

When running the test, you can specify some parameters to generate the performance file profile

-blockprofile block.out
    Write a goroutine blocking profile to the specified file
    when all tests are complete.
    Writes test binary as -c would.

-blockprofilerate n
    Control the detail provided in goroutine blocking profiles by
    calling runtime.SetBlockProfileRate with n.
    See 'go doc runtime.SetBlockProfileRate'.
    The profiler aims to sample, on average, one blocking event every
    n nanoseconds the program spends blocked. By default,
    if -test.blockprofile is set without this flag, all blocking events
    are recorded, equivalent to -test.blockprofilerate=1.

-coverprofile cover.out
    Write a coverage profile to the file after all tests have passed.
    Sets -cover.

-cpuprofile cpu.out
    Write a CPU profile to the specified file before exiting.
    Writes test binary as -c would.

-memprofile mem.out
    Write an allocation profile to the file after all tests have passed.
    Writes test binary as -c would.

-memprofilerate n
    Enable more precise (and expensive) memory allocation profiles by
    setting runtime.MemProfileRate. See 'go doc runtime.MemProfileRate'.
    To profile all memory allocations, use -test.memprofilerate=1.

-mutexprofile mutex.out
    Write a mutex contention profile to the specified file
    when all tests are complete.
    Writes test binary as -c would.

-mutexprofilefraction n
    Sample 1 in n stack traces of goroutines holding a
    contended mutex.

Use the following command to generate the CPU profile:

go test -v -bench="BenchmarkGenShortID$" --run=none -cpuprofile cpu.out ./util/

Under the current directory, it should generatecpu.outDocument andutil.testDocuments.

Use the following command to observe the time-consuming operation:

#Enter interactive mode
go tool pprof cpu.out

After you install graphviz, you can generate a visual analysis diagram

apt install graphviz
go tool pprof -http=":" cpu.out

Test coverage

[email protected]:/workspace# go test -v -coverprofile=cover.out ./util/
=== RUN   TestGenShortID
--- PASS: TestGenShortID (0.00s)
coverage: 9.1% of statements
ok      tzh.com/web/util        0.005s  coverage: 9.1% of statements

[email protected]:/workspace# go tool cover -func=cover.out
tzh.com/web/util/util.go:12:    GenShortID      100.0%
tzh.com/web/util/util.go:17:    GetReqID        0.0%
tzh.com/web/util/util.go:22:    TimeToStr       0.0%
tzh.com/web/util/util.go:30:    GetTag          0.0%
total:                          (statements)    9.1%

Use-coverprofile=cover.outOption to count test coverage
Usego tool cover -func=cover.outYou can view more detailed test coverage results,
Count the test coverage of each function


Testing is a very important part of development, to ensure the quality of software, must not be lazy

Code of current part

As version v0.15.0