代码异味 - 未经测试的正则表达式-java教程-PHP中文网

没有测试的正则表达式是自找麻烦 - 不要偷懒。它是免费的人工智能！

TL;DR：使用清晰简洁的正则表达式，并彻底测试它们。

问题

可读性
没有测试用例
错过了边缘情况
调试挑战
不清楚的失败
隐藏缺陷

解决方案

让你最喜欢的人工智能编写测试用例
将复杂的正则表达式分解为更小、更易读的部分。
检查边缘情况
验证输出
创建测试后重构正则表达式
改进错误消息

语境

正则表达式很强大，但也很棘手。

如果您在没有测试的情况下编写正则表达式，则会出现意外错误。

如果您编写神秘的正则表达式并跳过自动化测试，您可能会错过重要的案例，从而导致安全问题或用户沮丧。

示例代码

错误的

public class PasswordValidator {
    public static boolean isValidPassword(String password) {
        return password.matches(
            "^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)[a-zA-Z\d]{8,}$");
        // This is a cryptic Regular Expression
    }
}

登录后复制

正确的

import java.util.ArrayList;
import java.util.List;

public class PasswordValidator {
    public static List<String> validatePassword(String password) {
        List<String> errors = new ArrayList<>();

        if (password.length() < 8) {
            errors.add(
                "Password must be at least 8 characters long.");
        }
        if (!password.matches(".*[A-Z].*")) {
            errors.add(
                "Password must contain at least one uppercase letter.");
        }
        if (!password.matches(".*[a-z].*")) {
            errors.add(
                "Password must contain at least one lowercase letter.");
        }
        if (!password.matches(".*\d.*")) {
            errors.add(
                "Password must contain at least one digit.");
        }
        if (errors.isEmpty()) {
            errors.add(
                "Password is valid.");
        }
        return errors;
        // You no longer need a Regular Expression!!
    }
}

import static org.junit.Assert.*;
import org.junit.Test;

public class PasswordValidatorTest {
    // Now you have a lot of tests
    // You can use a Regular Expression,
    // a String Validator
    // an External Library
    // Whatever you want as long as it passes the tests!

    @Test
    public void testValidPassword() {
        List<String> result = 
            PasswordValidator.validatePassword(
            "StrongPass1");
        assertEquals("Password is valid.", result.get(0));
    }

    @Test
    public void testTooShortPassword() {
        List<String> result = PasswordValidator.validatePassword(
            "Short1");
        assertTrue(result.contains(
            "Password must be at least 8 characters long."));
    }

    @Test
    public void testNoUppercase() {
        List<String> result = PasswordValidator.validatePassword(
            "nouppercase1");
        assertTrue(
            result.contains(
                "Password must contain at least one uppercase letter."));
    }

    @Test
    public void testNoLowercase() {
        List<String> result = PasswordValidator.validatePassword(
            "NOLOWERCASE1");
        assertTrue(result.contains(
            "Password must contain at least one lowercase letter."));
    }

    @Test
    public void testNoNumber() {
        List<String> result = PasswordValidator.validatePassword(
            "NoNumberPass");
        assertTrue(result.contains(
            "Password must contain at least one digit."));
    }
}

登录后复制