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Testing GrepCommand CLI Parser Implementation in Alibaba Arthas

This test suite validates the functionality of the GrepCommand class in Alibaba Arthas, focusing on command-line argument parsing and configuration injection. The tests verify various grep command options including inverse matching, context lines, and string trimming behavior.

Test Coverage Overview

The test suite provides comprehensive coverage of GrepCommand functionality, focusing on three main command-line options.

Validates inverse matching with -v flag
Tests before-context line number specification
Verifies trim-end behavior configuration

Each test case ensures proper parsing and injection of command-line arguments into the GrepCommand instance.

Implementation Analysis

The testing approach utilizes JUnit framework with a setup-execute-verify pattern. Tests leverage the CLIConfigurator for command definition and parsing, demonstrating clean separation of concerns.

Each test follows a consistent structure:

Command argument preparation
Command instance creation
Parsing and injection
Assertion verification

Technical Details

Testing infrastructure includes:

JUnit 4 testing framework
CLI parsing utilities from taobao.middleware
CLIConfigurator for dependency injection
Assert class for test validations

Setup includes @Before annotation for CLI definition initialization before each test execution.

Best Practices Demonstrated

The test suite exemplifies several testing best practices:

Single responsibility principle with focused test methods
Proper exception handling and runtime error management
Clear test method naming convention
Consistent setup and teardown management
Isolated test cases with specific assertions

alibaba/arthas

core/src/test/java/com/taobao/arthas/core/command/basic1000/GrepCommandTest.java

            
package com.taobao.arthas.core.command.basic1000;

import java.util.Arrays;
import java.util.List;

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

import com.taobao.middleware.cli.CLI;
import com.taobao.middleware.cli.CommandLine;
import com.taobao.middleware.cli.annotations.CLIConfigurator;

/**
 * 
 * @author hengyunabc 2019-10-31
 *
 */
public class GrepCommandTest {

    private static CLI cli = null;

    @Before
    public void before() {
        cli = CLIConfigurator.define(GrepCommand.class);
    }

    @Test
    public void test() {
        List<String> args = Arrays.asList("-v", "ppp");
        GrepCommand grepCommand = new GrepCommand();
        CommandLine commandLine = cli.parse(args, true);

        try {
            CLIConfigurator.inject(commandLine, grepCommand);
        } catch (Throwable e) {
            throw new RuntimeException(e);
        }
        Assert.assertTrue(grepCommand.isInvertMatch());
    }

    @Test
    public void test2() {
        List<String> args = Arrays.asList("--before-context=6", "ppp");
        GrepCommand grepCommand = new GrepCommand();
        CommandLine commandLine = cli.parse(args, true);

        try {
            CLIConfigurator.inject(commandLine, grepCommand);
        } catch (Throwable e) {
            throw new RuntimeException(e);
        }
        Assert.assertEquals(6, grepCommand.getBeforeLines());
    }

    @Test
    public void test3() {
        List<String> args = Arrays.asList("--trim-end=false", "ppp");
        GrepCommand grepCommand = new GrepCommand();
        CommandLine commandLine = cli.parse(args, true);

        try {
            CLIConfigurator.inject(commandLine, grepCommand);
        } catch (Throwable e) {
            throw new RuntimeException(e);
        }
        Assert.assertFalse(grepCommand.isTrimEnd());
    }
}