使用多个输入来测试函数的效果

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我正在通过测试学习 go。我最终得到了“head first go”中第 2 章末尾的以下程序。

它让用户尝试猜测 1 到 10 之间的数字 3 次：

guess.go

package main

import (
    "fmt"
    "math/rand"
    "time"
    "bufio"
    "os"
    "log"
    "strconv"
    "strings"
)

func generaterandomnumber() int {
    rand.seed(time.now().unix())       // seed value based on time to generate non-deterministic random values
    randomnum := rand.intn(10) + 1     // range: [0, 10); produces the same value without seed(), i.e., pseudo-random
    return randomnum
}

func guess() int {
    var success bool = false
    target := generaterandomnumber()

    fmt.println("guess a number between 1 and 10")
    guess  := bufio.newreader(os.stdin)

    for attempts := 0; attempts < 3; attempts++ {
        fmt.println("you have", 3-attempts, "guesses left")
        userval, err := guess.readstring('\n')
        if err != nil {
            log.fatal(err)
        }
    
        input := strings.trimspace(userval)
        answer, err := strconv.atoi(input)
        if err != nil {
            log.fatal(err)
        }
    
        if answer == target {
            fmt.println("congratulations !!")
            return answer
        } else if answer > target {
            fmt.println("your guess was higher")
        } else if answer < target {
            fmt.println("your guess was lower")
        }
    }

    if !success {
        fmt.printf("sorry, you've run out of attempts... the correct value is %d\n", target)
        return target   
    }
    return 0
}

func main() {
    guess()
}

guess_test.go

package main

import (
    "testing"
)

func TestRandomNumber(t *testing.T) {
    want := generateRandomNumber()
    
    if 7 != want {
        t.Fail()
        t.Logf("Incorrect guess; The random number was %d", want)
    }
}

如何通过传入三个不同的输入来测试 guess()？

我想通过比较 guess() 和 generaterandomnumber() 的返回值来执行测试。

正确答案

您可以更改 guess 函数以从输入中获取阅读器，这样我们就可以将其传递给我们想要的任何阅读器：在 main 中，我们传递 stdin reader ，在测试中，我们传递模拟阅读器：

guess.go

package main

import (
    "bufio"
    "fmt"
    "log"
    "math/rand"
    "os"
    "strconv"
    "strings"
    "time"
)

func generaterandomnumber() int {
    rand.seed(time.now().unix())   // seed value based on time to generate non-deterministic random values
    randomnum := rand.intn(10) + 1 // range: [0, 10); produces the same value without seed(), i.e., pseudo-random
    return randomnum
}

func guess(reader *bufio.reader) (int, error) {
    target := generaterandomnumber()

    fmt.println("guess a number between 1 and 10")

    for attempts := 0; attempts < 3; attempts++ {
        fmt.println("you have", 3-attempts, "guesses left")
        userval, err := reader.readstring('\n')
        if err != nil {
            log.fatal(err)
        }

        input := strings.trimspace(userval)
        answer, err := strconv.atoi(input)
        if err != nil {
            log.fatal(err)
        }

        if answer == target {
            fmt.println("congratulations !!")
            return answer, nil
        } else if answer > target {
            fmt.println("your guess was higher")
        } else if answer < target {
            fmt.println("your guess was lower")
        }
    }

    fmt.printf("sorry, you've run out of attempts... the correct value is %d\n", target)
    return target, fmt.errorf("attempts is over")
}

func main() {
    reader := bufio.newreader(os.stdin)
    guess(reader)
}

用于测试：

guess_test.go

package main

import (
    "bufio"
    "fmt"
    "strings"
    "testing"
)

func TestRandomNumberOk(t *testing.T) {
    want := generateRandomNumber()
    msg := fmt.Sprintf("3\n4\n%d\n", want)
    reader := strings.NewReader(msg)
    r := bufio.NewReader(reader)
    _, err := guess(r)
    if err != nil {
        t.Errorf("guess must successfull")
    }
}

func TestRandomNumberFail(t *testing.T) {
    want := generateRandomNumber()
    msg := fmt.Sprintf("3\n4\n%d\n", want+1)
    reader := strings.NewReader(msg)
    r := bufio.NewReader(reader)
    _, err := guess(r)
    if err == nil {
        t.Errorf("guess must unsuccessfull")
    }
}

我必须改变你的猜测返回值，因为不知道什么时候成功或失败

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