問(wèn)題描述

從 PowerMock 主頁(yè)上的示例中，我看到了以下示例使用 Mockito 部分模擬私有方法:

From the examples on the PowerMock homepage, I see the following example for partially mocking a private method with Mockito:

@RunWith(PowerMockRunner.class)
// We prepare PartialMockClass for test because it's final or we need to mock private or static methods
@PrepareForTest(PartialMockClass.class)
public class YourTestCase {
@Test
public void privatePartialMockingWithPowerMock() {        
    PartialMockClass classUnderTest = PowerMockito.spy(new PartialMockClass());

    // use PowerMockito to set up your expectation
    PowerMockito.doReturn(value).when(classUnderTest, "methodToMock", "parameter1");

    // execute your test
    classUnderTest.execute();

    // Use PowerMockito.verify() to verify result
    PowerMockito.verifyPrivate(classUnderTest, times(2)).invoke("methodToMock", "parameter1");
}

但是，當(dāng)我們希望模擬的私有方法是靜態(tài)的時(shí)，這種方法似乎不起作用.我希望創(chuàng)建以下類(lèi)的部分模擬，并模擬 readFile 方法:

However, this approach does not seem to work when the private method we wish to mock is static. I wish to create a partial mock of the below class, with the readFile method mocked:

package org.rich.powermockexample;

import java.io.File;
import java.io.IOException;
import java.nio.charset.Charset;
import java.util.List;

import static com.google.common.io.Files.readLines;

public class DataProvider {

    public static List<String> getData() {
        List<String> data = null;
        try {
            data = readFile();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return data;
    }

    private static List<String> readFile() throws IOException {
        File file = new File("/some/path/to/file");
        List<String> lines = readLines(file, Charset.forName("utf-8"));
        return lines;
    }

}

請(qǐng)有人告訴我這是如何實(shí)現(xiàn)的嗎?

Please could someone let me know how this can be achieved?

推薦答案

經(jīng)過(guò)一番研究，這里似乎需要 PowerMockito.spy() 和 PowerMockito.doReturn() :

After doing a bit more research, it seems that PowerMockito.spy() and PowerMockito.doReturn() are what is required here:

package com.richashworth.powermockexample;

import org.junit.Before;
import org.junit.BeforeClass;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.powermock.api.mockito.PowerMockito;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;

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

import static org.junit.Assert.assertEquals;


@RunWith(PowerMockRunner.class)
@PrepareForTest({DataProvider.class})
public class ResultsWriterTest {

    private static List<String> mockData = new ArrayList<String>();
    private ResultsWriter resultsWriter;

    @BeforeClass
    public static void setUpOnce() {
        final String firstLine = "Line 1";
        final String secondLine = "Line 2";
        mockData.add(firstLine);
        mockData.add(secondLine);
    }

    @Before
    public void setUp() {
        resultsWriter = new ResultsWriter();
    }

    @Test
    public void testGetDataAsString() throws Exception {
        PowerMockito.spy(DataProvider.class);
        PowerMockito.doReturn(mockData).when(DataProvider.class, "readFile");

        final String expectedData = "Line 1
Line 2
";
        final String returnedString = resultsWriter.getDataAsString();

        assertEquals(expectedData, returnedString);
    }

}

有關(guān)更多詳細(xì)信息和完整代碼清單，請(qǐng)?jiān)诖颂幉榭次业牟┛臀恼?https://richashworth.com/post/turbocharge-your-mocking-framework-with-powermock/

For further details and the complete code listing, check out my blog post here: https://richashworth.com/post/turbocharge-your-mocking-framework-with-powermock/

這篇關(guān)于是否可以在 PowerMock 中對(duì)私有靜態(tài)方法使用部分模擬?的文章就介紹到這了，希望我們推薦的答案對(duì)大家有所幫助，也希望大家多多支持html5模板網(wǎng)！