可以进行合理的单元测试？

Question

是否可以为此代码编写合理的单元测试,通过将其委托给主机系统上的有用工具(如果存在)来提取rar存档？我可以根据我的机器运行linux并安装unrar工具来编写一个测试用例,但是如果另一个运行windows的开发人员检查代码,测试会失败,尽管提取器代码没有任何问题.我需要找到一种方法来编写一个没有绑定到系统和unrar工具的有意义的测试.你会如何解决这个问题？

public class Extractor {

private EventBus eventBus;
private ExtractCommand[] linuxExtractCommands = new ExtractCommand[]{new LinuxUnrarCommand()};
private ExtractCommand[] windowsExtractCommands = new ExtractCommand[]{};
private ExtractCommand[] macExtractCommands = new ExtractCommand[]{};

@Inject
public Extractor(EventBus eventBus) {
    this.eventBus = eventBus;
}

public boolean extract(DownloadCandidate downloadCandidate) {
    for (ExtractCommand command : getSystemSpecificExtractCommands()) {
        if (command.extract(downloadCandidate)) {
            eventBus.fireEvent(this, new ExtractCompletedEvent());
            return true;
        }
    }

    eventBus.fireEvent(this, new ExtractFailedEvent());
    return false;
}

private ExtractCommand[] getSystemSpecificExtractCommands() {
    String os = System.getProperty("os.name");
    if (Pattern.compile("linux", Pattern.CASE_INSENSITIVE).matcher(os).find()) {
        return linuxExtractCommands;
    } else if (Pattern.compile("windows", Pattern.CASE_INSENSITIVE).matcher(os).find()) {
        return windowsExtractCommands;
    } else if (Pattern.compile("mac os x", Pattern.CASE_INSENSITIVE).matcher(os).find()) {
        return macExtractCommands;
    }

    return null;
}

}

Answer 1

您是否可以将类传递给Map<String,ExtractCommand[]>实例,然后创建一个抽象方法,例如GetOsName,使字符串匹配.然后你可以在地图中查找匹配字符串以获取getSystemSpecificExtractCommands方法中的提取命令.这将允许您注入包含模拟的列表ExtractCommand并覆盖该GetOsName方法以返回模拟命令的键,因此您可以测试当提取工作时,eventBus触发等.

private Map<String,EvenetCommand[]> eventMap;

@Inject
public Extractor(EventBus eventBus, Map<String,EventCommand[]> eventMap) {
    this.eventBus = eventBus;
    this.eventMap = eventMap;
}

private ExtractCommand[] getSystemSpecificExtractCommands() {
    String os = GetOsName();
    return eventMap.Get(os);
}

protected GetOsName();
{
    return System.getProperty("os.name");
}