<!DOCTYPE HTML>
<html>
<head>
  <meta charset='UTF-8'>
  <script src='/tests/SimpleTest/SimpleTest.js'></script>
  <link rel='stylesheet' href='/tests/SimpleTest/test.css'>
</head>
<body>
<script>
'use strict';

function RunWithPrefs(prefPairList, func) {
  var prefEnv = {'set': prefPairList};
  try {
    SpecialPowers.pushPrefEnv(prefEnv, func);
  } catch (e) {
    console.log('Warning: Failed to set prefs: ' + JSON.stringify(prefPairList));
    func();
  }
}

////////////////////////////////////////

function Check(expr, text) {
  ok(expr, text);
  return expr;
}

function TestWhenDisabled() {
  var c = document.createElement('canvas');

  var generatedEvent = null;
  var f = function(event) { generatedEvent = event; };
  c.addEventListener('webglcontextcreationerror', f);

  var gl = c.getContext('webgl'); // Should fail.

  do {
    if (!Check(!gl, 'When disabled, context creation should fail.'))
      break;

    if (!Check(generatedEvent, 'Context creation failure should generate an event.'))
      break;

    var reason = generatedEvent.statusMessage;
    if (!Check(reason !== undefined, 'generatedEvent.statusMessage should be defined.'))
      break;

    ok(reason.length, 'statusMessage should be non-empty.');
  } while (false);

  SimpleTest.finish();
}

////////////////////////////////////////

SimpleTest.waitForExplicitFinish();

var prefPairList = [
  ['webgl.disabled', true],
];
RunWithPrefs(prefPairList, TestWhenDisabled);

</script>
</body>
</html>
