使用 Junit 测试 InputStream

Question

我正在尝试在我的 class "UserInput".

中测试函数 "DataFeatures"

无论我在测试中给出什么参数，它总是通过。

字段和构造函数

public @Getter class UserInput {
    FileType type;
    FileOperation operation;
    SynchronizationMethod method;
    String path;
    private static InputReader in = new InputReader();

    public UserInput() {
        // Dont need to do anything
    }

要测试的函数

    void getDataFeatures() {
    System.out.println("For encryption press 1");
    System.out.println("For decryption press 0");
    operation = FileOperation.fromInt(in.nextInt());

    System.out.println("For a file choose 1");
    System.out.println("For an entire directory choose 0");
    type = FileType.fromInt(in.nextInt());

    if (type == FileType.DIR) {
        System.out.println("For sync press 1");
        System.out.println("For async press 0");
        method = SynchronizationMethod.fromInt(in.nextInt());
    }
}

我的测试

public class UserInputTest {

UserInput UI;
private final ByteArrayOutputStream outContent = new ByteArrayOutputStream();
private final ByteArrayOutputStream errContent = new ByteArrayOutputStream();
private final PrintStream oldStdOut = System.out;
private final PrintStream oldStdErr = System.err;
private final InputStream oldStdIn = System.in;

@Before
public void initlize(){
    System.setOut(new PrintStream(outContent));
    System.setErr(new PrintStream(errContent));
    UI = new UserInput();
}

@Test
public void getDataFeaturesTest() {
    String data = "0" + "\n0" + "\n0";
    System.setIn(new ByteArrayInputStream(data.getBytes()));
    UI.getDataFeatures();
    System.out.println(UI.getOperation());
    assertThat(UI.getOperation(), is(equalTo(FileOperation.decryption)));
    assertThat(UI.getType(), is(equalTo(FileType.FILE)));
    assertThat(UI.getMethod(), is(equalTo(SynchronizationMethod.SYNC)));


}

@After
public void cleanUpStreams() {
    System.setOut(oldStdOut);
    System.setErr(oldStdErr);
    System.setIn(oldStdIn);
}

}

注1：FileOperation、FileType和SynchronizationMethod都是取1或0的枚举。

同步方法示例：

public enum SynchronizationMethod {
SYNC(1), ASYNC(0);

private int method;

private SynchronizationMethod(int meth) {
    this.method = meth;
}

public static SynchronizationMethod fromInt(int meth) {
    for (SynchronizationMethod SM : SynchronizationMethod.values()) {
        if (SM.method == meth) {
            return SM;
        }
    }
    throw new IllegalArgumentException("No constant with method " + meth + " found");
}

public String toString(){
    if (method == 1){
        return "Sync";
    }
    else if(method == 0){
        return "ASync";
    }
    else{
        throw new IllegalArgumentException("No constant with method " + method + " found in toString");
    }
}

}

解决方案

问题出在构造函数中的 class InputReader。

    public InputReader() {
    reader = new BufferedReader(new InputStreamReader(System.in));
    tokenizer = null;
}

这个函数中的 reader 和 Junit 函数中的 Input Stream 如评论中所建议的那样断开连接

Answer 1

猜测这里 - 你的 UserInput class 说：

private static InputReader in = new InputReader();

而你的测试用例说：

String data = "0" + "\n0" + "\n0";
System.setIn(new ByteArrayInputStream(data.getBytes()));

换句话说：可能断开连接。根据 InputReader 背后的实施，您可能只是从错误的来源阅读。

使用 Junit 测试 InputStream

Test InputStream with Junit

java

junit

inputstream