Go language foundation ------ 14 ------ gotest

1 precondition ：

• 1、 The file name must be in "_test.go" ending .
• 2、 Method name must be "Test" Lead , And the formal parameter is (t *testing.T).

2 give an example

gotest.go( This is only the internal file used in the test file , So there's no need to _test.go ending )：

package mytest

import (
    "errors"
)

func Division(a, b float64) (float64, error) {
    
    if b == 0 {
    
        return 0, errors.New(" The divisor cannot be zero 0")
    }
    return a / b, nil
}

This is the real test file ：
gotest_test.go：

package mytest

import (
	"testing"
)

func Test_Division_1(t *testing.T) {
    
	if i, e := Division(6, 2); i != 3 || e != nil {
     //try a unit test on function
		t.Error(" Division function test failed ") //  If it's not as expected, report an error 
	} else {
    
		t.Log(" The first test passed ") // Record some information you expect to record 
	}
}

func Test_Division_2(t *testing.T) {
    
	if _, e := Division(6, 0); e != nil {
     //try a unit test on function
		t.Error("Division did not work as expected.") //  If it's not as expected, report an error 
	} else {
    
		t.Log("one test passed.") // Record some information you expect to record 
	}
}

3 Go test test

1.  Execute... In the directory  go test  Is the test directory all with XXX_test.go  Final document .

2. Testing individual methods 
go test -v -run="Test_Division_1" -count 5

3. view help  go help test

 adopt go help test You can see go test Instructions for use ：
 The format is like ：
go test [-c] [-i] [build flags] [packages] [flags for test binary]
 Parameter interpretation ：
-c :  compile go test Become an executable binary , But don't run tests .
-i :  The installation test package depends on package, But don't run tests .
 About build flags, call go help build, These are the parameters that need to be used in compiling and running , Generally set to empty 
 About packages, call go help packages, These are about package management , Generally set to empty 
 About flags for test binary, call go help testflag, These are go test Parameters often used in the process 
-test.v :  Whether to output all unit test cases （ No matter success or failure ）, Default does not add , So just output failed unit test cases .
-test.run pattern:  Which unit test cases only to run 
-test.bench patten:  Run only those performance test cases 
-test.benchmem :  Whether to output the memory condition during the performance test 
-test.benchtime t :  Time of performance test run , The default is 1s
-test.cpuprofile cpu.out :  Whether the output cpu Performance analysis file 
-test.memprofile mem.out :  Whether to output memory performance analysis file 
-test.blockprofile block.out :  Whether to output internal goroutine Blocked performance analysis file 
-test.memprofilerate n :  During the memory performance analysis, there is a problem of how much memory is allocated before recording . This parameter is set to hit 
 Point memory allocation interval , That is to say profile In a sample Represents the memory size of . The default setting is 512 * 1024 Of . If you set it 
 by 1, Every memory block allocated will be in profile One of them is a little bit , So the generated profile Of sample There will be a lot of . If you set it to 0,
 That's to say, we don't need to do some maintenance .
 You can set up memprofilerate=1 and GOGC=off To turn off memory recycling , And observe the allocation of each memory block .
-test.blockprofilerate n:  Basically the same as above , Control is goroutine The number of nanoseconds in the block . Default no setting is equivalent to -
test.blockprofilerate=1, Record every nanosecond 
-test.parallel n :  Program parallelism in performance testing cpu Count , Default equal to GOMAXPROCS. -test.timeout t :  If the test case runs longer than t, Throw out panic
-test.cpu 1,2,4 :  Where does the program run CPU above , Use binary 1 On behalf of , and nginx Of nginx_worker_cpu_affinity It's one 
 A reason 
-test.short :  Reduce the running time of test cases with longer running time