CODEWITHSUNDEEP
javajunit
Madhawas
Madhawas

Reputation: 391

JUnit force BufferedReader to throw IOException

I have following method 

    public static String readPostParams(Request request, String param) {

    BufferedReader br = new BufferedReader(new InputStreamReader(request.getBodyAsStream()));
    String line;

    try {
        while ((line = br.readLine()) != null) {
            if (line.contains(param)) {
                //System.out.println("---> " + param + " :" + getValue(line));
                return getValue(line);
            }
        }
    } catch (IOException ex) {
        // Ignore
    }
    return "";
}

I want a JUnit Unit test to force BufferedReader to throw IOException so I can cover that part also.

Upvotes: 0

Views: 2176

Answers (2)

Nicholas Robinson
Nicholas Robinson

Reputation: 1419

You should get an IOException if the file is "in use" So you can try this:
(I have never tested this)

In you test use

final RandomAccessFile lockFile = new RandomAccessFile(fileName, "rw");
lockFile.getChannel().lock();

Then call your method from above and unlock the file once you are done.

Upvotes: 1

Constantine
Constantine

Reputation: 1406

If you want to test this method for IOException, you should propagate the exception to the calling method by removing the try catch block and adding the throws clause to your method:

    public static String readPostParams(Request request, String param) throws IOException;

There is an attribute called as 'expected' for the @Test annotation which you can use to check for exceptions. Your test case which checks for IOexception from your method will look somewhat like this:

@Test(expected=IOException.class)
public void shouldReadPostParamsThrowIOExceptionIfInvalidRead(){
}

Upvotes: 0

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