<!--
Copyright (c) 2019 The Khronos Group Inc.
Use of this source code is governed by an MIT-style license that can be
found in the LICENSE.txt file.
-->
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<link rel="stylesheet" href="../../resources/js-test-style.css"/>
<script src="../../js/js-test-pre.js"></script>
<script src="../../js/webgl-test-utils.js"></script>
<script src="../../js/tests/canvas-tests-utils.js"></script>
<script>
function init()
{
    description("Tests behavior under a lost context for OffscreenCanvas");

    if (!window.OffscreenCanvas) {
      testPassed("No OffscreenCanvas support");
      finishTest();
      return;
    }

    canvas = new OffscreenCanvas(10, 10);
    gl = canvas.getContext('webgl');

    // call testValidContext() before checking for the extension, because this is where we check
    // for the isContextLost() method, which we want to do regardless of the extension's presence.
    if (!testValidContext()) {
        testFailed("Some tests failed");
        finishTest();
        return;
    }

    extension = gl.getExtension("WEBGL_lose_context");
    // need an extension that exposes new API methods.
    OES_vertex_array_object = gl.getExtension("OES_vertex_array_object");
    if (extension == null || OES_vertex_array_object == null) {
        testFailed("Some tests failed");
        finishTest();
        return;
    }

    // We need to initialize |uniformLocation| before losing context.
    // Otherwise gl.getUniform() when context is lost will throw.
    uniformLocation = gl.getUniformLocation(program, "tex");
    extension.loseContext();

    canvas.addEventListener("webglcontextlost", function() {
        if (testLostContextWithoutRestore()) {
            testPassed("All tests passed");
            finishTest();
            return;
        } else {
            testFailed("Some tests failed");
            finishTest();
            return;
        }
    }, false);
}

</script>
</head>
<body onload="init()">
<div id="description"></div>
<div id="console"></div>
</body>
</html>
