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Validating Regex Pattern Matching Implementation in Alibaba Arthas

This test suite validates the RegexMatcher utility in Alibaba Arthas, focusing on regular expression pattern matching functionality. The suite comprehensively tests various regex patterns and edge cases to ensure robust string matching capabilities.

Test Coverage Overview

The test suite provides extensive coverage of regex pattern matching scenarios.

Key areas tested include:

Null input handling
Basic regex grammar elements (?, ., *, +)
Character classes (\s, \S, \w, \W)
Complex regex patterns (IP addresses, email validation)
Boundary conditions (^, $)

Implementation Analysis

The testing approach utilizes JUnit’s assertion framework to validate regex matching behavior systematically. The implementation follows a progressive complexity pattern, starting with basic null checks and advancing to complex pattern matching scenarios.

Test methods are organized into three distinct categories:

Null input validation
Regular grammar testing
Complex pattern matching

Technical Details

Testing tools and configuration:

JUnit 4 testing framework
Assert class for validation
RegexMatcher custom utility class
Java-based pattern matching implementation
Test cases structured with @Test annotations

Best Practices Demonstrated

The test suite exemplifies several testing best practices.

Notable aspects include:

Comprehensive edge case coverage
Clear test method naming conventions
Systematic progression from simple to complex scenarios
Thorough validation of both positive and negative test cases
Well-documented test cases with clear purpose

alibaba/arthas

core/src/test/java/com/taobao/arthas/core/util/matcher/RegexMatcherTest.java

            
package com.taobao.arthas.core.util.matcher;

import org.junit.Assert;
import org.junit.Test;

/**
 * @author earayu
 */
public class RegexMatcherTest {

    @Test
    public void testMatchingWithNullInputs(){
        Assert.assertFalse(new RegexMatcher(null).matching(null));
        Assert.assertFalse(new RegexMatcher(null).matching("foobar"));
        Assert.assertFalse(new RegexMatcher("foobar").matching(null));
        Assert.assertTrue(new RegexMatcher("foobar").matching("foobar"));
    }

    /**
     * test regux with . | * + ? \s \S \w \W and so on...
     */
    @Test
    public void testMatchingWithRegularGrammar(){
        Assert.assertTrue(new RegexMatcher("foo?").matching("fo"));
        Assert.assertTrue(new RegexMatcher("foo?").matching("foo"));
        Assert.assertTrue(new RegexMatcher("foo.").matching("fooo"));
        Assert.assertTrue(new RegexMatcher("foo*").matching("fooooo"));
        Assert.assertTrue(new RegexMatcher("foo.*").matching("foobarbarbar"));
        Assert.assertFalse(new RegexMatcher("foo+").matching("fo"));
        Assert.assertTrue(new RegexMatcher("foo+").matching("fooooo"));

        Assert.assertTrue(new RegexMatcher("foo\\s").matching("foo "));
        Assert.assertFalse(new RegexMatcher("foo\\S").matching("foo "));
        Assert.assertTrue(new RegexMatcher("foo\\w").matching("fooo"));
        Assert.assertTrue(new RegexMatcher("foo\\W").matching("foo "));
        Assert.assertFalse(new RegexMatcher("foo\\W").matching("fooo"));


        Assert.assertTrue(new RegexMatcher("foo[1234]").matching("foo1"));
        Assert.assertFalse(new RegexMatcher("foo[1234]").matching("foo5"));
        Assert.assertTrue(new RegexMatcher("foo\\\\").matching("foo\\"));
        Assert.assertTrue(new RegexMatcher("foo\\d").matching("foo5"));
        Assert.assertTrue(new RegexMatcher("fo{1,3}").matching("fo"));
        Assert.assertFalse(new RegexMatcher("fo{1,3}").matching("foooo"));
    }

    @Test
    public void testMatchingComplexRegex(){
        String ipAddressPattern = "((2[0-4]\\d|25[0-5]|[01]?\\d\\d?)\\.){3}(2[0-4]\\d|25[0-5]|[01]?\\d\\d?)";
        Assert.assertTrue(new RegexMatcher(ipAddressPattern).matching("1.1.1.1"));
        Assert.assertFalse(new RegexMatcher(ipAddressPattern).matching("255.256.255.0"));
        Assert.assertFalse(new RegexMatcher(ipAddressPattern).matching("1.1.1"));

        Assert.assertTrue(new RegexMatcher("^foobar$").matching("foobar"));
        Assert.assertFalse(new RegexMatcher("^foobar$").matching("\nfoobar"));
        Assert.assertFalse(new RegexMatcher("^foobar$").matching("foobar\n"));

        String emailAddressPattern = "[a-z\\d]+(\\.[a-z\\d]+)*@([\\da-z](-[\\da-z])?)+(\\.{1,2}[a-z]+)+";
        Assert.assertTrue(new RegexMatcher(emailAddressPattern).matching("[email protected]"));
        Assert.assertFalse(new RegexMatcher(emailAddressPattern).matching("asdfghjkl"));
    }

}