用go和ginkgo测试Stdout

Question

在这里,我正在尝试在go命令行应用程序上进行BDD.我正在使用Ginkgo,它包装了testing.go并让你做更具表现力的BDD.https://github.com/onsi/ginkgo

我在阅读stdout以解决问题时遇到了问题.

发现在pkg/testing示例中运行之前存根输出但我无法找到读取该输出的方法:http://golang.org/src/pkg/testing/example.go

这就是我想做的事情:

cli.go

 package cli

 import "fmt"

 func Run() {
        fmt.Println("Running cli")
 }

cli_test.go

package cli_test

import (
        . "github.com/altoros/bosh_deployer_cli/lib/cli"

        . "github.com/onsi/ginkgo"
        . "github.com/onsi/gomega"
)

var _ = Describe("Cli", func() {
        It("should parse update stemcell flag", func() {
                Run()
                Expect(stdout).To(Equal("running cli"))
        })
})

Answer 1

测试Stdout可能很棘手.你有多种选择.

您可以在测试期间覆盖os.Stdout :(想想检查错误)

var _ = Describe("Cli", func() {
        It("should parse update stemcell flag", func() {
                r, w, _ := os.Pipe()
                tmp := os.Stdout
                defer func() {
                        os.Stdout = tmp
                }()
                os.Stdout = w
                go func() {
                        Run()
                        w.Close()
                }()
                stdout, _ := ioutil.ReadAll(r)
                Expect(string(stdout)).To(Equal("Running cli\n"))
        })
})

或者您可以将作者传递给您的函数:

cli.go

package cli

import (
        "fmt"
        "io"
)

func Run(w io.Writer) {
        fmt.Fprintln(w, "Running cli")
}

cli_test.go

package cli_test

import (
        . "cli"
        "io"
        "io/ioutil"

        . "github.com/onsi/ginkgo"
        . "github.com/onsi/gomega"
)

var _ = Describe("Cli", func() {
        It("should parse update stemcell flag", func() {
                r, w := io.Pipe()
                go func() {
                        Run(w)
                        w.Close()
                }()
                stdout, _ := ioutil.ReadAll(r)
                Expect(string(stdout)).To(Equal("Running cli\n"))
        })
})

main.go

package main

import (
        "cli"
        "os"
)

func main() {
        cli.Run(os.Stdout)
}