Mockito Mocking Android Context PackageManager Exception

Posted 2023-02-04

我开始使用Mockito进行android无头单元测试。我要测试的部分是在后端，它依赖于Context。我尝试模拟上下文，但是当我运行测试时我得到null。

在这个例子中看到的模拟上下文并没有告诉我它是如何被嘲笑的：https://developer.android.com/training/testing/unit-testing/local-unit-tests.html#setup

上面链接中提到的示例（https://github.com/googlesamples/android-testing/tree/master/unit/BasicSample）没有关于如何模拟上下文的示例。

所以我有点失落。

我的gradle依赖项中包含以下内容：

testCompile 'junit:junit:4.12'
    androidTestCompile 'com.android.support.test:runner:0.4'
    androidTestCompile 'com.android.support.test:rules:0.4'
    androidTestCompile 'com.android.support:support-annotations:23.0.1'
    testCompile 'org.mockito:mockito-core:1.10.19'
    androidTestCompile('com.android.support.test:testing-support-lib:0.+')

代码片段：

@RunWith(MockitoJUnitRunner.cass)
public static Test 
  @Mock Context mContext;
  RequestQueue mQueue;

@Test public void getCategories()
final String SERVER = "http://.../categories";
mContext = mock(Context.class);
int size = 20;
when(mContext.getResources().getInteger(R.integer.cache_size)).thenReturn(size);
mQueue = VolleyUtil.newRequestQueue(mContext, null, size);

final Response.Listener<String> listener = new Response.Listener()
//...


Response.ErrorListener error = new Response.ErrorListener()
///...


mQueue.add(new JsonRequest(SERVER, listener, error);


VolleyUtil.newRequestQueue(final Context context, HttpStack stack, final int cacheMB)
final File cacheDir = new File(context.getCacheDir(), "volley");
  if(stack == null) 
     if(Build.VERSION.SDK_INT >= 9) 
        stack = new HurlStack();
      else 
        String userAgent = "volley/0";

        try 
           final String network = context.getPackageName();
           final PackageInfo queue = context.getPackageManager().getPackageInfo(network, 0);
           userAgent = network + "/" + queue.versionCode;
         catch (PackageManager.NameNotFoundException e) 
           e.printStacktrace();
        

        stack = new HttpClientStack(AndroidHttpClient.newInstance(userAgent));
     
  

  final BasicNetwork network = new BasicNetwork((HttpStack)stack);
  final RequestQueue queue = new RequestQueue(new DiskBasedCache(cacheDir,diskCacheMB*1000000), network);
  queue.start();
  return queue;

我的null异常发生在：

final PackageInfo queue = context.getPackageManager().getPackageInfo(network, 0);

我想模拟包管理器或应用程序实例？

答案

既然你没有在JUnit上测试android资源，你也需要模拟它。例如：

PackageInfo pi = new PackgeInfo();
// modify it's value the way you desire
when(mContext.getPackageManager().getPackageInfo(network, 0)).thenReturn(pi);

然后继续进行单元测试。