【翻译】【Go】Go Modules的用法

简介

go.modgo.modgo.modGOPATHGOPATHgo.modGOPATH

创建模块

$GOPATH/srchello.go

package hello

func Hello() string {
    return "Hello, world"
}

hello_test.go

package hello

import "testing"

func TestHello(t *testing.T) {
	want := "Hello,world"
	if got := Hello(); got != want {
		t.Errorf("Hello() = %q, want %q", got, want)
	}
}

go.modgo test

D:\Code\go>go test
PASS
ok      _/D_/Code/go    0.327s
D:\Code\go>

$GOPATH_/D_/Code/gogo mod initgo test

D:\Code\go>go mod init example.com/hello
go: creating new go.mod: module example.com/hello

D:\Code\go>go test
PASS
ok      example.com/hello       0.393s

D:\Code\go>

go mod initgo.mod

PS D:\Code\go> cat .\go.mod                                                                                                                                                                   module example.com/hello                                                                                                                                                                      
go 1.12
PS D:\Code\go>

go.modworldgo mod initexample.com/helloexample.com/hello/world

添加依赖

hello.gorsc.io/quote

package hello

import "rsc.io/quote"

func Hello() string {
	return quote.Hello()
}

go test

D:\Code\go>go test
go: finding golang.org/x/text v0.0.0-20170915032832-14c0d48ead0c
go: downloading rsc.io/sampler v1.3.0
go: extracting rsc.io/sampler v1.3.0
go: downloading golang.org/x/text v0.0.0-20170915032832-14c0d48ead0c
go: extracting golang.org/x/text v0.0.0-20170915032832-14c0d48ead0c
--- FAIL: TestHello (0.00s)
    hello_test.go:10: Hello() = "Hello, world.", want "Hello, world"
FAIL
exit status 1
FAIL    example.com/hello       0.431s

D:\Code\go>

go.modgo.modgo.modgo testrsc.io/quotersc.io/quotersc.io/samplergolang.org/x/testgo.mod

D:\Code\go>type go.mod
module example.com/hello

go 1.12

require rsc.io/quote v1.5.2

D:\Code\go>

go testgo.modgo list -m

yankeweideMacBook-Pro:hello yankewei$ go list -m all
hello
golang.org/x/text v0.0.0-20170915032832-14c0d48ead0c
rsc.io/quote v1.5.2
rsc.io/sampler v1.3.0
yankeweideMacBook-Pro:hello yankewei$ 

golang.org/x/text v0.0.0-20170915032832-14c0d48ead0c

yankeweideMacBook-Pro:hello yankewei$ cat go.sum
golang.org/x/text v0.0.0-20170915032832-14c0d48ead0c h1:qgOY6WgZOaTkIIMiVjBQcw93ERBE4m30iBm00nkL0i8=
golang.org/x/text v0.0.0-20170915032832-14c0d48ead0c/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
rsc.io/quote v1.5.2 h1:w5fcysjrx7yqtD/aO+QwRjYZOKnaM9Uh2b40tElTs3Y=
rsc.io/quote v1.5.2/go.mod h1:LzX7hefJvL54yjefDEDHNONDjII0t9xZLPXsUe+TKr0=
rsc.io/sampler v1.3.0 h1:7uVkIFmeBqHfdjD+gZwtXXI+RODJ2Wc4O7MPEh/QiW4=
rsc.io/sampler v1.3.0/go.mod h1:T1hPZKmBbMNahiBKFy5HrXp6adAjACjK9JXDnKaTXpA=
yankeweideMacBook-Pro:hello yankewei$ 

go使用go.sum文件来确保未来下载这些模块的时候保证和第一次下载的一样，也确保你项目的依赖不会改变，所以go.mod和go.sum都应该纳入版本控制中。

更新依赖

go list -m allgolang.org/x/text

$ go get golang.org/x/text
go: finding golang.org/x/text v0.3.0
go: downloading golang.org/x/text v0.3.0
go: extracting golang.org/x/text v0.3.0
$ go test
PASS
ok      example.com/hello    0.013s
$

go list -m all

$ go list -m all
example.com/hello
golang.org/x/text v0.3.0
rsc.io/quote v1.5.2
rsc.io/sampler v1.3.0
$ cat go.mod
module example.com/hello

go 1.12

require (
    golang.org/x/text v0.3.0 // indirect
    rsc.io/quote v1.5.2
)
$

golang.org/x/testindirectgo help modules

rsc.io/sampler

$ go get rsc.io/sampler
go: finding rsc.io/sampler v1.99.99
go: downloading rsc.io/sampler v1.99.99
go: extracting rsc.io/sampler v1.99.99
$ go test
--- FAIL: TestHello (0.00s)
    hello_test.go:8: Hello() = "99 bottles of beer on the wall, 99 bottles of beer, ...", want "Hello, world."
FAIL
exit status 1
FAIL    example.com/hello    0.014s
$

Shit！测试失败了，最新的版本和我们要使用的不兼容，先看一下这个模块的可用版本：

$ go list -m -versions rsc.io/sampler
rsc.io/sampler v1.0.0 v1.2.0 v1.2.1 v1.3.0 v1.3.1 v1.99.99
$

我们已经使用过v1.3.0；v1.99.99版本不兼容，可以尝试使用v1.3.1:

$ go get rsc.io/sampler@v1.3.1
go: finding rsc.io/sampler v1.3.1
go: downloading rsc.io/sampler v1.3.1
go: extracting rsc.io/sampler v1.3.1
$ go test
PASS
ok      example.com/hello    0.022s
$

go get@v1.3.1@latest

添加一个新的主版本

func Proverbrsc.io/quote/v3quote.Concurrency

package hello

import (
	"rsc.io/quote"
	quoteV3 "rsc.io/quote/v3"
)

func Hello() string {
	return quote.Hello()
}

func Proverb() string {
	return quoteV3.Concurrency()
}

然后在hello_test.go添加一个测试：

func TestProverb(t *testing.T) {
    want := "Concurrency is not parallelism."
    if got := Proverb(); got != want {
        t.Errorf("Proverb() = %q, want %q", got, want)
    }
}

现在可以执行代码：

$ go test
go: finding rsc.io/quote/v3 v3.1.0
go: downloading rsc.io/quote/v3 v3.1.0
go: extracting rsc.io/quote/v3 v3.1.0
PASS
ok      example.com/hello    0.024s
$

rsc.io/quotersc.io/quote/v3

更新依赖为新的主版本

rsc.io/quotersc.io/quote/v3

$ go doc rsc.io/quote/v3
package quote // import "rsc.io/quote/v3"

Package quote collects pithy sayings.

func Concurrency() string
func GlassV3() string
func GoV3() string
func HelloV3() string
func OptV3() string**

可以看到原来的 Hello 改为了 HelloV3，那我们就可以把使用的 Hello 改为 HelloV3，并且文件中没有对旧版本的依赖了，可以把导入重命名去掉：

package hello

import (
	"rsc.io/quote/v3"
)

func Hello() string {
	return quote.HelloV3()
}

func Proverb() string {
	return quote.Concurrency()
}

可以自行测试，就不演示了。

删除未使用的依赖

go mod tidy