Hello World - 第一个测试

Hello World：PHPUnit 第一个测试

目标

学习 PHPUnit 基础：创建测试类、编写断言、运行测试、理解测试结果。

完整代码

1. 项目结构

math-app/
├── src/
│   └── Calculator.php
├── tests/
│   └── CalculatorTest.php
├── phpunit.xml
└── composer.json

2. src/Calculator.php

<?php

namespace App;

class Calculator
{
    public function add(float $a, float $b): float
    {
        return $a + $b;
    }

    public function subtract(float $a, float $b): float
    {
        return $a - $b;
    }

    public function multiply(float $a, float $b): float
    {
        return $a * $b;
    }

    public function divide(float $a, float $b): float
    {
        if ($b === 0.0) {
            throw new \InvalidArgumentException('Division by zero');
        }
        return $a / $b;
    }

    public function fibonacci(int $n): array
    {
        if ($n < 0) {
            throw new \InvalidArgumentException('Negative input');
        }

        $sequence = [0, 1];
        for ($i = 2; $i <= $n; $i++) {
            $sequence[] = $sequence[$i - 1] + $sequence[$i - 2];
        }

        return array_slice($sequence, 0, $n + 1);
    }
}

3. tests/CalculatorTest.php

<?php

namespace App\Tests;

use App\Calculator;
use PHPUnit\Framework\TestCase;

class CalculatorTest extends TestCase
{
    private Calculator $calculator;

    protected function setUp(): void
    {
        $this->calculator = new Calculator();
    }

    public function testAdd(): void
    {
        $this->assertSame(4.0, $this->calculator->add(2.0, 2.0));
        $this->assertSame(0.0, $this->calculator->add(-1.0, 1.0));
    }

    public function testSubtract(): void
    {
        $this->assertSame(3.0, $this->calculator->subtract(5.0, 2.0));
    }

    public function testMultiply(): void
    {
        $this->assertSame(6.0, $this->calculator->multiply(2.0, 3.0));
    }

    public function testDivide(): void
    {
        $this->assertSame(2.5, $this->calculator->divide(5.0, 2.0));
    }

    public function testDivideByZeroThrowsException(): void
    {
        $this->expectException(\InvalidArgumentException::class);
        $this->expectExceptionMessage('Division by zero');

        $this->calculator->divide(5.0, 0.0);
    }

    #[DataProvider('fibonacciProvider')]
    public function testFibonacci(int $input, array $expected): void
    {
        $this->assertSame($expected, $this->calculator->fibonacci($input));
    }

    public static function fibonacciProvider(): array
    {
        return [
            'zero'  => [0, [0]],
            'one'   => [1, [0, 1]],
            'five'  => [5, [0, 1, 1, 2, 3, 5]],
            'ten'   => [10, [0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55]],
        ];
    }

    public function testFibonacciNegativeThrowsException(): void
    {
        $this->expectException(\InvalidArgumentException::class);
        $this->calculator->fibonacci(-1);
    }
}

运行步骤

./vendor/bin/phpunit
# 或带详细输出
./vendor/bin/phpunit --testdox

预期输出

PHPUnit 11.0.x by Sebastian Bergmann and contributors.

.......                                                         7 / 7 (100%)

Time: 00:00.012, Memory: 6.00 MB

OK (7 tests, 15 assertions)

TestDox 格式：

Calculator
 ✔ Add
 ✔ Subtract
 ✔ Multiply
 ✔ Divide
 ✔ Divide by zero throws exception
 ✔ Fibonacci with data set "zero"
 ✔ Fibonacci with data set "one"
 ✔ Fibonacci with data set "five"
 ✔ Fibonacci with data set "ten"
 ✔ Fibonacci negative throws exception

常用断言速查

断言	用途
assertSame($a, $b)	严格等于（类型+值）
assertEquals($a, $b)	宽松等于
assertTrue($x)	为 true
assertFalse($x)	为 false
assertNull($x)	为 null
assertCount($n, $arr)	数组元素数
assertContains($v, $arr)	包含某值
expectException(Class::class)	预期异常