Contributing WebGL conformance tests Guidelines

Thank you for contributing to the WebGL conformance tests. Please try to follow these guidelines when submitting a test.

  • If you're new to git here's a terse set of instructions.

  • All changes and/or new tests should go in the sdk/tests folder:

  • Tests that apply to WebGL 1 to sdk/tests/conformance

  • Tests that only concern WebGL 2 to sdk/tests/conformance2

The tests under conformance-suites are snapshots and are only to be updated by the WebGL Working Group when “official” snapshots are taken.

  • Please use the Khronos Group License (MIT)

These lines must appear in a comment at the top of every code file under sdk/tests/conformance

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.
  • Please use code similar to the code in existing tests

    Ideally, copy an existing test and modify it for your new test. Try not to duplicate code that already exists where appropriate. In particular

    • use the functions in WebGLTestUtils rather than duplicating functionality.

      In particular, as much as possible, keep the WebGL code in your test specific to the issue being tested and try to use the helper functions to handle common setup.


      • to create a WebGL context call WebGLTestUtils.create3DContext. Passed nothing it will create an offscreen canvas. Passed a canvas element it will create a context on that element. Passed a string it will look up the canvas element with the matching id and create a context from that element.

      • use WebGLTestUtils.checkCanvas or WebGLTestUtils.checkCanvasRect rather than checking rendering results by hand.

      • use the various quad and draw functions

        • WebGLTestUtils.setupUnitQuad and WebGLTestUtils.clearAndDrawUnitQuad for simple drawing.

        • WebGLTestUtils.setupColorQuad, WebGLTestUtils.drawFloatColorQuad, and WebGLTestUilts.drawUByteColorQuad for drawing in a particular color.

        • WebGLTestUtils.setupIndexedQuad and WebGLTestUtils.clearAndDrawIndexedQuad if you need a higher subdivision of vertices and/or vertex colors.

        • use WebgLTestUtils.setupTexturedQuad if you need a unit quad with texture coords. By default the positions will be at location 0 and the texture coords at location 1.

      • If you need a custom shader use WebGLTestUtils.setupProgram. Note that it takes the following arguments. gl, shaders, opt_attribs, opt_locations, and opt_logShaders where:

        gl is the WebGL context.

        shaders are an array of either script element ids, shader source, or WebGLShader objects. The first element in the array is the vertex shader, the second the fragment shader.

        opt_attribs is an optional array of attribute names. If provided the named attributes will have their locations bound to their index in this array.

        opt_locations is an optional array of attribute locations. If provided each attribute name in opt_attribs is bound to the corresponding location in opt_locations.

        opt_logShaders is an optional boolean value. If set to true, the shader source will be logged on the test page. It is recommended to use this in tests that concentrate on shaders.

      • If you need to wait for a composite call WebGLTestUtils.waitForComposite. As compositing is a browser specific thing this provides a central place to update all tests that rely on compositing to function.

      • If you don't care about composition, wtu.dispatchPromise makes it easy to yield back to the event loop.

    • Code/Tag Order

      Most tests run inline. They don't use window.onload or the load event. This works by placing the script tag inside the body, after the canvas and required divs.

      <canvas id="example"></canvas>
      <div id="description"></div>
      <div id="console"></div>
      var wtu = WebGLDebugUtils;
      var gl = wtu.create3DContext("example");
    • Ending Tests

      • Tests that are short and run synchronously end with

        <script src="../../resources/js-test-post.js"></script>
      • Tests that take a long time use setTimeout so as not to freeze the browser.

        Many browsers will terminate JavaScript that takes more than a few seconds to execute without returning control to the browser. The workaround is code like this

        var numTests = 10;
        var currenTest = 0;
        function runNextTest() {
          if (currentTest == numTests) {
            finishTest();  // Tells the harness you're done.
          // Run your test.
          setTimeout(runNextTest, 100);

        Remember the tests need to run without timing out even and slow mobile devices. The harness resets the timeout timer every time a test reports success or failure so as long as some part of your test calls testPassed or testFailed or one of the many wrappers (shouldXXX, glErrorShouldBe, WebGLTestUtils.checkCanvasXXX, etc..) every so often the harness will not timeout your test.

      • The test harness requires the global variable successfullyParsed to be set to true. This usually appears at the end of a file.

        var successfullyParsed = true;
    • Do not use browser specific code.

      • Do not check the browser version. Use feature detection.

      • If you do need feature detection consider putting it into WebGLTestUtils so that other tests can go through the same abstraction and the workaround is isolated to one place.

      • Vendors may place test harness specific code in the testing infrastructure.

    • Indent with spaces not tabs. (not everyone uses your tab settings).

    • All HTML files must have a <!DOCTYPE html>

    • All HTML files must have a <meta charset="utf-8">

    • All JavaScript must start with “use strict”;

  • If adding a new test edit the appropriate 00_test_list.txt file

    Each folder has a 00_test_list.txt file that lists the test in that folder. Each new test should be prefixed with the option --min-version <version> where version is 1 more than the newest official version. At the time of this writing all new tests should be prefixed with --min-version 1.0.4 or --min-version 2.0.1.