[Java] JUnit: How create assertTrue: Image exists or not ?

Supposing you are fully on the Java level:

use
Match m = Screen.exists("some-image.png")
or
Match m = Region.exists("some-image.png")

m is set to null, if the image could not be found.

Can I ask for some clarification on this answer?

I'm in the same boat here and using match is always coming back with a match whether or not the image appears on the screen. I never get a null result. My console is always showing results such as:

Match[247,102 157x16] score 1.00, target=center

the height of the match lets me think you are searching for some text on the screen?

If it is really an image, you are looking for, than in this case it is there at 247,102 157x16.

(exception: totally black and totally white images, there we have a bug)

So what are you doing?

I'm using Sikuli in Eclipse to simply double click on an icon and verify the application launches. I've purposely set it up to verify a completely incorrect image comes up as I want to see it fail but it never does. It launches the application correctly but always passes the ensureExists method no matter what image I try to match.

I created the following method to verify the failure as the following:

public boolean ensureExists(String image) {

 Match m = s.exists(image);
 System.out.println("Result of m is " + s.exists(image));

 if (s.exists(image) != null) {
  return true;
 }
 return false;
}

This is the test that pulls in that method

Screen s = new Screen();

@Test
public void testLaunchApp() throws FindFailed {
 s.doubleClick(img, 0);
 Assert.assertTrue(ensureExists(screenshot));
}

No idea, seems ok.

But I would write it:

public boolean ensureExists(String image) {

 Match m = s.exists(image);

 if (m != null) {
 System.out.println("Result of m is " + m);
 return true;
 }
 return false;
}

Only to be sure: screenshot is a string containing a filename ending with .png?

Yes the image name is a filename ending with .png extension.

Strange enough after modifying my code to match what you wrote it all started failing. After putting it back it to what I had it now works correctly with the right things passing and the wrong things failing. When that starts happening I feel a case of testers tourrets coming on.

Thanks for the help.