1 files changed, 825 insertions, 0 deletions

diff --git a/dom/canvas/test/webgl-conf/checkout/js/tests/canvas-tests-utils.js b/dom/canvas/test/webgl-conf/checkout/js/tests/canvas-tests-utils.js
new file mode 100644
index 0000000000..7c30104379
--- /dev/null
+++ b/dom/canvas/test/webgl-conf/checkout/js/tests/canvas-tests-utils.js
@@ -0,0 +1,825 @@
+/*
+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.
+*/
+
+// Some variables that will be used in this file
+var canvas;
+var gl;
+var OES_vertex_array_object;
+var uniformLocation;
+var extension;
+var buffer;
+var framebuffer;
+var program;
+var renderbuffer;
+var shader;
+var texture;
+var arrayBuffer;
+var arrayBufferView;
+var vertexArrayObject;
+var imageData;
+var float32array;
+var int32array;
+
+var OES_texture_float;
+var new_WEBGL_lose_context;
+var allowRestore;
+var contextLostEventFired;
+var contextRestoredEventFired;
+var newExtension;
+
+function compareGLError(glError, evalStr) {
+    var exception;
+    try {
+        eval(evalStr);
+    } catch (e) {
+        exception = e;
+    }
+    if (exception) {
+        return false;
+    } else {
+        if (gl.getError() == glError)
+            return true;
+        return false;
+    }
+}
+
+function contextCreation(contextType) {
+    canvas = new OffscreenCanvas(10, 10);
+    gl = canvas.getContext(contextType);
+
+    if (contextType == 'webgl') {
+        if (gl instanceof WebGLRenderingContext)
+            return true;
+        return false;
+    } else if (contextType == 'webgl2') {
+        if (gl instanceof WebGL2RenderingContext)
+            return true;
+        return false;
+    } else {
+        return false;
+    }
+}
+
+function transferredOffscreenCanvasCreation(placeholder, width, height) {
+  placeholder.width = width;
+  placeholder.height = height;
+  return placeholder.transferControlToOffscreen();
+}
+
+function assertWidthAndHeight(entity, entityName, width, height) {
+ if (entity.width == width && entity.height == height) {
+   testPassed("The width and height of " + entityName + " are correct.");
+   return;
+ }
+ var errMsg = "";
+ if (entity.width != width) {
+   errMsg += "The width of " + entityName + " is " + entity.width + " while expected value is " + width + ". ";
+ }
+ if (entity.height != height) {
+   errMsg += "The height of " + entityName + " is " + entity.height + " while expected value is " + height + ". ";
+ }
+ testFailed(errMsg);
+}
+
+var webgl1Methods = [
+  "getContextAttributes",
+  "activeTexture",
+  "attachShader",
+  "bindAttribLocation",
+  "bindBuffer",
+  "bindFramebuffer",
+  "bindRenderbuffer",
+  "bindTexture",
+  "blendColor",
+  "blendEquation",
+  "blendEquationSeparate",
+  "blendFunc",
+  "blendFuncSeparate",
+  "bufferData",
+  "bufferSubData",
+  "checkFramebufferStatus",
+  "clear",
+  "clearColor",
+  "clearDepth",
+  "clearStencil",
+  "colorMask",
+  "compileShader",
+  "compressedTexImage2D",
+  "compressedTexSubImage2D",
+  "copyTexImage2D",
+  "copyTexSubImage2D",
+  "createBuffer",
+  "createFramebuffer",
+  "createProgram",
+  "createRenderbuffer",
+  "createShader",
+  "createTexture",
+  "cullFace",
+  "deleteBuffer",
+  "deleteFramebuffer",
+  "deleteProgram",
+  "deleteRenderbuffer",
+  "deleteShader",
+  "deleteTexture",
+  "depthFunc",
+  "depthMask",
+  "depthRange",
+  "detachShader",
+  "disable",
+  "disableVertexAttribArray",
+  "drawArrays",
+  "drawElements",
+  "enable",
+  "enableVertexAttribArray",
+  "finish",
+  "flush",
+  "framebufferRenderbuffer",
+  "framebufferTexture2D",
+  "frontFace",
+  "generateMipmap",
+  "getActiveAttrib",
+  "getActiveUniform",
+  "getAttachedShaders",
+  "getAttribLocation",
+  "getParameter",
+  "getBufferParameter",
+  "getError",
+  "getExtension",
+  "getFramebufferAttachmentParameter",
+  "getProgramParameter",
+  "getProgramInfoLog",
+  "getRenderbufferParameter",
+  "getShaderParameter",
+  "getShaderInfoLog",
+  "getShaderPrecisionFormat",
+  "getShaderSource",
+  "getSupportedExtensions",
+  "getTexParameter",
+  "getUniform",
+  "getUniformLocation",
+  "getVertexAttrib",
+  "getVertexAttribOffset",
+  "hint",
+  "isBuffer",
+  "isContextLost",
+  "isEnabled",
+  "isFramebuffer",
+  "isProgram",
+  "isRenderbuffer",
+  "isShader",
+  "isTexture",
+  "lineWidth",
+  "linkProgram",
+  "pixelStorei",
+  "polygonOffset",
+  "readPixels",
+  "renderbufferStorage",
+  "sampleCoverage",
+  "scissor",
+  "shaderSource",
+  "stencilFunc",
+  "stencilFuncSeparate",
+  "stencilMask",
+  "stencilMaskSeparate",
+  "stencilOp",
+  "stencilOpSeparate",
+  "texImage2D",
+  "texParameterf",
+  "texParameteri",
+  "texSubImage2D",
+  "uniform1f",
+  "uniform1fv",
+  "uniform1i",
+  "uniform1iv",
+  "uniform2f",
+  "uniform2fv",
+  "uniform2i",
+  "uniform2iv",
+  "uniform3f",
+  "uniform3fv",
+  "uniform3i",
+  "uniform3iv",
+  "uniform4f",
+  "uniform4fv",
+  "uniform4i",
+  "uniform4iv",
+  "uniformMatrix2fv",
+  "uniformMatrix3fv",
+  "uniformMatrix4fv",
+  "useProgram",
+  "validateProgram",
+  "vertexAttrib1f",
+  "vertexAttrib1fv",
+  "vertexAttrib2f",
+  "vertexAttrib2fv",
+  "vertexAttrib3f",
+  "vertexAttrib3fv",
+  "vertexAttrib4f",
+  "vertexAttrib4fv",
+  "vertexAttribPointer",
+  "viewport",
+];
+
+var webgl2Methods = [
+  "getBufferSubData",
+  "copyBufferSubData",
+  "blitFramebuffer",
+  "framebufferTextureLayer",
+  "getInternalformatParameter",
+  "invalidateFramebuffer",
+  "invalidateSubFramebuffer",
+  "readBuffer",
+  "renderbufferStorageMultisample",
+  "texImage3D",
+  "texStorage2D",
+  "texStorage3D",
+  "texSubImage3D",
+  "copyTexSubImage3D",
+  "compressedTexImage3D",
+  "compressedTexSubImage3D",
+  "getFragDataLocation",
+  "uniform1ui",
+  "uniform2ui",
+  "uniform3ui",
+  "uniform4ui",
+  "uniform1uiv",
+  "uniform2uiv",
+  "uniform3uiv",
+  "uniform4uiv",
+  "uniformMatrix2x3fv",
+  "uniformMatrix3x2fv",
+  "uniformMatrix2x4fv",
+  "uniformMatrix4x2fv",
+  "uniformMatrix3x4fv",
+  "uniformMatrix4x3fv",
+  "vertexAttribI4i",
+  "vertexAttribI4iv",
+  "vertexAttribI4ui",
+  "vertexAttribI4uiv",
+  "vertexAttribIPointer",
+  "vertexAttribDivisor",
+  "drawArraysInstanced",
+  "drawElementsInstanced",
+  "drawRangeElements",
+  "drawBuffers",
+  "clearBufferiv",
+  "clearBufferuiv",
+  "clearBufferfv",
+  "clearBufferfi",
+  "createQuery",
+  "deleteQuery",
+  "isQuery",
+  "beginQuery",
+  "endQuery",
+  "getQuery",
+  "getQueryParameter",
+  "createSampler",
+  "deleteSampler",
+  "isSampler",
+  "bindSampler",
+  "samplerParameteri",
+  "samplerParameterf",
+  "getSamplerParameter",
+  "fenceSync",
+  "isSync",
+  "deleteSync",
+  "clientWaitSync",
+  "waitSync",
+  "getSyncParameter",
+  "createTransformFeedback",
+  "deleteTransformFeedback",
+  "isTransformFeedback",
+  "bindTransformFeedback",
+  "beginTransformFeedback",
+  "endTransformFeedback",
+  "transformFeedbackVaryings",
+  "getTransformFeedbackVarying",
+  "pauseTransformFeedback",
+  "resumeTransformFeedback",
+  "bindBufferBase",
+  "bindBufferRange",
+  "getIndexedParameter",
+  "getUniformIndices",
+  "getActiveUniforms",
+  "getUniformBlockIndex",
+  "getActiveUniformBlockParameter",
+  "getActiveUniformBlockName",
+  "uniformBlockBinding",
+  "createVertexArray",
+  "deleteVertexArray",
+  "isVertexArray",
+  "bindVertexArray",
+];
+
+function assertFunction(v, f) {
+    try {
+        if (typeof v[f] != "function") {
+            return false;
+        } else {
+            return true;
+        }
+    } catch(e) {
+        return false;
+    }
+}
+
+function testAPIs(contextType) {
+    canvas = new OffscreenCanvas(10, 10);
+    gl = canvas.getContext(contextType);
+    var passed = true;
+    var methods;
+    if (contextType == 'webgl')
+        methods = webgl1Methods;
+    else
+        methods = webgl1Methods.concat(webgl2Methods);
+    for (var i=0; i<methods.length; i++) {
+      var r = assertFunction(gl, methods[i]);
+      passed = passed && r;
+    }
+
+    methods.push(...["makeXRCompatible"]);
+    var extended = false;
+    for (var i in gl) {
+      if (typeof gl[i] == "function" && methods.indexOf(i) == -1) {
+        if (!extended) {
+          extended = true;
+        }
+      }
+    }
+
+    if (!passed || extended)
+        return false;
+    return true;
+}
+
+var simpleTextureVertexShader = [
+  'attribute vec4 vPosition;',
+  'attribute vec2 texCoord0;',
+  'varying vec2 texCoord;',
+  'void main() {',
+  '    gl_Position = vPosition;',
+  '    texCoord = texCoord0;',
+  '}'].join('\n');
+
+var simpleTextureFragmentShader = [
+  'precision mediump float;',
+  'uniform sampler2D tex;',
+  'varying vec2 texCoord;',
+  'void main() {',
+  '    gl_FragData[0] = texture2D(tex, texCoord);',
+  '}'].join('\n');
+
+function getShader(gl, shaderStr, type)
+{
+  var shader = gl.createShader(type);
+  gl.shaderSource(shader, shaderStr);
+  gl.compileShader(shader);
+
+  if (!gl.getShaderParameter(shader, gl.COMPILE_STATUS))
+    return null;
+  return shader;
+}
+
+function setupProgram(gl, shaders, opt_attribs, opt_locations)
+{
+  var vertexShader = getShader(gl, simpleTextureVertexShader, gl.VERTEX_SHADER);
+  var fragmentShader = getShader(gl, simpleTextureFragmentShader, gl.FRAGMENT_SHADER);
+  var program = gl.createProgram();
+  gl.attachShader(program, vertexShader);
+  gl.attachShader(program, fragmentShader);
+
+  if (opt_attribs) {
+    for (var ii = 0; ii < opt_attribs.length; ++ii) {
+      gl.bindAttribLocation(
+          program,
+          opt_locations ? opt_locations[ii] : ii,
+          opt_attribs[ii]);
+    }
+  }
+  gl.linkProgram(program);
+
+  // Check the link status
+  var linked = gl.getProgramParameter(program, gl.LINK_STATUS);
+  if (!linked) {
+      // something went wrong with the link
+      gl.deleteProgram(program);
+      return null;
+  }
+  gl.useProgram(program);
+  return program;
+}
+
+function setupSimpleTextureProgram(gl, opt_positionLocation, opt_texcoordLocation)
+{
+  opt_positionLocation = opt_positionLocation || 0;
+  opt_texcoordLocation = opt_texcoordLocation || 1;
+  return setupProgram(gl,
+                      [simpleTextureVertexShader, simpleTextureFragmentShader],
+                      ['vPosition', 'texCoord0'],
+                      [opt_positionLocation, opt_texcoordLocation]);
+}
+
+function testLostContextWithoutRestore()
+{
+    // Functions with special return values.
+    if (!gl.isContextLost())
+        return false;
+
+    if (gl.getError() != gl.CONTEXT_LOST_WEBGL)
+        return false;
+    if (gl.getError() != gl.NO_ERROR)
+        return false;
+
+    if (gl.checkFramebufferStatus(gl.FRAMEBUFFER) != gl.FRAMEBUFFER_UNSUPPORTED ||
+        gl.getAttribLocation(program, 'u_modelViewProjMatrix') != -1 ||
+        gl.getVertexAttribOffset(0, gl.VERTEX_ATTRIB_ARRAY_POINTER) != 0)
+        return false;
+
+    // Test the extension itself.
+    if (!compareGLError(gl.INVALID_OPERATION, "extension.loseContext()"))
+        return false;
+
+    imageData = new ImageData(1, 1);
+    float32array = new Float32Array(1);
+    int32array = new Int32Array(1);
+
+    // Functions returning void should return immediately.
+    // This is untestable, but we can at least be sure they cause no errors
+    // and the codepaths are exercised.
+    if (!compareGLError(gl.NO_ERROR, "gl.activeTexture(gl.TEXTURE0)") ||
+        !compareGLError(gl.NO_ERROR, "gl.attachShader(program, shader)") ||
+        !compareGLError(gl.NO_ERROR, "gl.bindBuffer(gl.ARRAY_BUFFER, buffer)") ||
+        !compareGLError(gl.NO_ERROR, "gl.bindFramebuffer(gl.FRAMEBUFFER, framebuffer)") ||
+        !compareGLError(gl.NO_ERROR, "gl.bindRenderbuffer(gl.RENDERBUFFER, renderbuffer)") ||
+        !compareGLError(gl.NO_ERROR, "gl.bindTexture(gl.TEXTURE_2D, texture)") ||
+        !compareGLError(gl.NO_ERROR, "gl.blendColor(1.0, 1.0, 1.0, 1.0)") ||
+        !compareGLError(gl.NO_ERROR, "gl.blendEquation(gl.FUNC_ADD)") ||
+        !compareGLError(gl.NO_ERROR, "gl.blendEquationSeparate(gl.FUNC_ADD, gl.FUNC_ADD)") ||
+        !compareGLError(gl.NO_ERROR, "gl.blendFunc(gl.ONE, gl.ONE)") ||
+        !compareGLError(gl.NO_ERROR, "gl.blendFuncSeparate(gl.ONE, gl.ONE, gl.ONE, gl.ONE)") ||
+        !compareGLError(gl.NO_ERROR, "gl.bufferData(gl.ARRAY_BUFFER, 0, gl.STATIC_DRAW)") ||
+        !compareGLError(gl.NO_ERROR, "gl.bufferData(gl.ARRAY_BUFFER, arrayBufferView, gl.STATIC_DRAW)") ||
+        !compareGLError(gl.NO_ERROR, "gl.bufferData(gl.ARRAY_BUFFER, arrayBuffer, gl.STATIC_DRAW)") ||
+        !compareGLError(gl.NO_ERROR, "gl.bufferSubData(gl.ARRAY_BUFFRE, 0, arrayBufferView)") ||
+        !compareGLError(gl.NO_ERROR, "gl.bufferSubData(gl.ARRAY_BUFFRE, 0, arrayBuffer)") ||
+        !compareGLError(gl.NO_ERROR, "gl.clear(gl.COLOR_BUFFER_BIT)") ||
+        !compareGLError(gl.NO_ERROR, "gl.clearColor(1, 1, 1, 1)") ||
+        !compareGLError(gl.NO_ERROR, "gl.clearDepth(1)") ||
+        !compareGLError(gl.NO_ERROR, "gl.clearStencil(0)") ||
+        !compareGLError(gl.NO_ERROR, "gl.colorMask(1, 1, 1, 1)") ||
+        !compareGLError(gl.NO_ERROR, "gl.compileShader(shader)") ||
+        !compareGLError(gl.NO_ERROR, "gl.copyTexImage2D(gl.TEXTURE_2D, 0, gl.RGBA, 0, 0, 0, 0, 0)") ||
+        !compareGLError(gl.NO_ERROR, "gl.copyTexSubImage2D(gl.TEXTURE_2D, 0, 0, 0, 0, 0, 0, 0)") ||
+        !compareGLError(gl.NO_ERROR, "gl.cullFace(gl.FRONT)") ||
+        !compareGLError(gl.NO_ERROR, "gl.deleteBuffer(buffer)") ||
+        !compareGLError(gl.NO_ERROR, "gl.deleteFramebuffer(framebuffer)") ||
+        !compareGLError(gl.NO_ERROR, "gl.deleteProgram(program)") ||
+        !compareGLError(gl.NO_ERROR, "gl.deleteRenderbuffer(renderbuffer)") ||
+        !compareGLError(gl.NO_ERROR, "gl.deleteShader(shader)") ||
+        !compareGLError(gl.NO_ERROR, "gl.deleteTexture(texture)") ||
+        !compareGLError(gl.NO_ERROR, "gl.depthFunc(gl.NEVER)") ||
+        !compareGLError(gl.NO_ERROR, "gl.depthMask(0)") ||
+        !compareGLError(gl.NO_ERROR, "gl.depthRange(0, 1)") ||
+        !compareGLError(gl.NO_ERROR, "gl.detachShader(program, shader)") ||
+        !compareGLError(gl.NO_ERROR, "gl.disable(gl.BLEND)") ||
+        !compareGLError(gl.NO_ERROR, "gl.disableVertexAttribArray(0)") ||
+        !compareGLError(gl.NO_ERROR, "gl.drawArrays(gl.POINTS, 0, 0)") ||
+        !compareGLError(gl.NO_ERROR, "gl.drawElements(gl.POINTS, 0, gl.UNSIGNED_SHORT, 0)") ||
+        !compareGLError(gl.NO_ERROR, "gl.enable(gl.BLEND)") ||
+        !compareGLError(gl.NO_ERROR, "gl.enableVertexAttribArray(0)") ||
+        !compareGLError(gl.NO_ERROR, "gl.finish()") ||
+        !compareGLError(gl.NO_ERROR, "gl.flush()") ||
+        !compareGLError(gl.NO_ERROR, "gl.framebufferRenderbuffer(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.RENDERBUFFER, renderbuffer)") ||
+        !compareGLError(gl.NO_ERROR, "gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, texture, 0)") ||
+        !compareGLError(gl.NO_ERROR, "gl.frontFace(gl.CW)") ||
+        !compareGLError(gl.NO_ERROR, "gl.generateMipmap(gl.TEXTURE_2D)") ||
+        !compareGLError(gl.NO_ERROR, "gl.hint(gl.GENERATE_MIPMAP_HINT, gl.FASTEST)") ||
+        !compareGLError(gl.NO_ERROR, "gl.lineWidth(0)") ||
+        !compareGLError(gl.NO_ERROR, "gl.linkProgram(program)") ||
+        !compareGLError(gl.NO_ERROR, "gl.pixelStorei(gl.UNPACK_FLIP_Y_WEBGL, 0)") ||
+        !compareGLError(gl.NO_ERROR, "gl.polygonOffset(0, 0)") ||
+        !compareGLError(gl.NO_ERROR, "gl.readPixels(0, 0, 0, 0, gl.RGBA, gl.UNSIGNED_BYTE, arrayBufferView)") ||
+        !compareGLError(gl.NO_ERROR, "gl.renderbufferStorage(gl.RENDERBUFFER, gl.RGBA4, 0, 0)") ||
+        !compareGLError(gl.NO_ERROR, "gl.sampleCoverage(0, 0)") ||
+        !compareGLError(gl.NO_ERROR, "gl.scissor(0, 0, 0, 0)") ||
+        !compareGLError(gl.NO_ERROR, "gl.shaderSource(shader, '')") ||
+        !compareGLError(gl.NO_ERROR, "gl.stencilFunc(gl.NEVER, 0, 0)") ||
+        !compareGLError(gl.NO_ERROR, "gl.stencilFuncSeparate(gl.FRONT, gl.NEVER, 0, 0)") ||
+        !compareGLError(gl.NO_ERROR, "gl.stencilMask(0)") ||
+        !compareGLError(gl.NO_ERROR, "gl.stencilMaskSeparate(gl.FRONT, 0)") ||
+        !compareGLError(gl.NO_ERROR, "gl.stencilOp(gl.KEEP, gl.KEEP, gl.KEEP)") ||
+        !compareGLError(gl.NO_ERROR, "gl.stencilOpSeparate(gl.FRONT, gl.KEEP, gl.KEEP, gl.KEEP)") ||
+        !compareGLError(gl.NO_ERROR, "gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, 0, 0, 0, gl.RGBA, gl.UNSIGNED_BYTE, arrayBufferView)") ||
+        !compareGLError(gl.NO_ERROR, "gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, gl.RGBA, gl.UNSIGNED_BYTE, imageData)") ||
+        !compareGLError(gl.NO_ERROR, "gl.texParameterf(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST)") ||
+        !compareGLError(gl.NO_ERROR, "gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST)") ||
+        !compareGLError(gl.NO_ERROR, "gl.texSubImage2D(gl.TEXTURE_2D, 0, 0, 0, 0, 0, gl.RGBA, gl.UNSIGNED_BYTE, arrayBufferView)") ||
+        !compareGLError(gl.NO_ERROR, "gl.texSubImage2D(gl.TEXTURE_2D, 0, 0, 0, gl.RGBA, gl.UNSIGNED_BYTE, imageData)") ||
+        !compareGLError(gl.NO_ERROR, "gl.uniform1f(uniformLocation, 0)") ||
+        !compareGLError(gl.NO_ERROR, "gl.uniform1fv(uniformLocation, float32array)") ||
+        !compareGLError(gl.NO_ERROR, "gl.uniform1fv(uniformLocation, [0])") ||
+        !compareGLError(gl.NO_ERROR, "gl.uniform1i(uniformLocation, 0)") ||
+        !compareGLError(gl.NO_ERROR, "gl.uniform1iv(uniformLocation, int32array)") ||
+        !compareGLError(gl.NO_ERROR, "gl.uniform1iv(uniformLocation, [0])") ||
+        !compareGLError(gl.NO_ERROR, "gl.uniform2f(uniformLocation, 0, 0)") ||
+        !compareGLError(gl.NO_ERROR, "gl.uniform2fv(uniformLocation, float32array)") ||
+        !compareGLError(gl.NO_ERROR, "gl.uniform2fv(uniformLocation, [0, 0])") ||
+        !compareGLError(gl.NO_ERROR, "gl.uniform2i(uniformLocation, 0, 0)") ||
+        !compareGLError(gl.NO_ERROR, "gl.uniform2iv(uniformLocation, int32array)") ||
+        !compareGLError(gl.NO_ERROR, "gl.uniform2iv(uniformLocation, [0, 0])") ||
+        !compareGLError(gl.NO_ERROR, "gl.uniform3f(uniformLocation, 0, 0, 0)") ||
+        !compareGLError(gl.NO_ERROR, "gl.uniform3fv(uniformLocation, float32array)") ||
+        !compareGLError(gl.NO_ERROR, "gl.uniform3fv(uniformLocation, [0, 0, 0])") ||
+        !compareGLError(gl.NO_ERROR, "gl.uniform3i(uniformLocation, 0, 0, 0)") ||
+        !compareGLError(gl.NO_ERROR, "gl.uniform3iv(uniformLocation, int32array)") ||
+        !compareGLError(gl.NO_ERROR, "gl.uniform3iv(uniformLocation, [0, 0, 0])") ||
+        !compareGLError(gl.NO_ERROR, "gl.uniform4f(uniformLocation, 0, 0, 0, 0)") ||
+        !compareGLError(gl.NO_ERROR, "gl.uniform4fv(uniformLocation, float32array)") ||
+        !compareGLError(gl.NO_ERROR, "gl.uniform4fv(uniformLocation, [0, 0, 0, 0])") ||
+        !compareGLError(gl.NO_ERROR, "gl.uniform4i(uniformLocation, 0, 0, 0, 0)") ||
+        !compareGLError(gl.NO_ERROR, "gl.uniform4iv(uniformLocation, int32array)") ||
+        !compareGLError(gl.NO_ERROR, "gl.uniform4iv(uniformLocation, [0, 0, 0, 0])") ||
+        !compareGLError(gl.NO_ERROR, "gl.uniformMatrix2fv(uniformLocation, false, float32array)") ||
+        !compareGLError(gl.NO_ERROR, "gl.uniformMatrix2fv(uniformLocation, false, [0, 0, 0, 0])") ||
+        !compareGLError(gl.NO_ERROR, "gl.uniformMatrix3fv(uniformLocation, false, float32array)") ||
+        !compareGLError(gl.NO_ERROR, "gl.uniformMatrix3fv(uniformLocation, false, [0, 0, 0, 0, 0, 0, 0, 0, 0])") ||
+        !compareGLError(gl.NO_ERROR, "gl.uniformMatrix4fv(uniformLocation, false, float32array)") ||
+        !compareGLError(gl.NO_ERROR, "gl.uniformMatrix4fv(uniformLocation, false, [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0])") ||
+        !compareGLError(gl.NO_ERROR, "gl.useProgram(program)") ||
+        !compareGLError(gl.NO_ERROR, "gl.validateProgram(program)") ||
+        !compareGLError(gl.NO_ERROR, "gl.vertexAttrib1f(0, 0)") ||
+        !compareGLError(gl.NO_ERROR, "gl.vertexAttrib1fv(0, float32array)") ||
+        !compareGLError(gl.NO_ERROR, "gl.vertexAttrib1fv(0, [0])") ||
+        !compareGLError(gl.NO_ERROR, "gl.vertexAttrib2f(0, 0, 0)") ||
+        !compareGLError(gl.NO_ERROR, "gl.vertexAttrib2fv(0, float32array)") ||
+        !compareGLError(gl.NO_ERROR, "gl.vertexAttrib2fv(0, [0, 0])") ||
+        !compareGLError(gl.NO_ERROR, "gl.vertexAttrib3f(0, 0, 0, 0)") ||
+        !compareGLError(gl.NO_ERROR, "gl.vertexAttrib3fv(0, float32array)") ||
+        !compareGLError(gl.NO_ERROR, "gl.vertexAttrib3fv(0, [0, 0, 0])") ||
+        !compareGLError(gl.NO_ERROR, "gl.vertexAttrib4f(0, 0, 0, 0, 0)") ||
+        !compareGLError(gl.NO_ERROR, "gl.vertexAttrib4fv(0, float32array)") ||
+        !compareGLError(gl.NO_ERROR, "gl.vertexAttrib4fv(0, [0, 0, 0, 0])") ||
+        !compareGLError(gl.NO_ERROR, "gl.vertexAttribPointer(0, 0, gl.FLOAT, false, 0, 0)") ||
+        !compareGLError(gl.NO_ERROR, "gl.viewport(0, 0, 0, 0)"))
+        return false;
+
+    // Functions return nullable values should all return null.
+    if (gl.createBuffer() != null ||
+        gl.createFramebuffer() != null ||
+        gl.createProgram() != null ||
+        gl.createRenderbuffer() != null ||
+        gl.createShader(gl.GL_VERTEX_SHADER) != null ||
+        gl.createTexture() != null ||
+        gl.getActiveAttrib(program, 0) != null ||
+        gl.getActiveUniform(program, 0) != null ||
+        gl.getAttachedShaders(program) != null ||
+        gl.getBufferParameter(gl.ARRAY_BUFFER, gl.BUFFER_SIZE) != null ||
+        gl.getContextAttributes() != null ||
+        gl.getFramebufferAttachmentParameter(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.FRAMEBUFFER_ATTACHMENT_OBJECT_NAME) != null ||
+        gl.getParameter(gl.CURRENT_PROGRAM) != null ||
+        gl.getProgramInfoLog(program) != null ||
+        gl.getProgramParameter(program, gl.LINK_STATUS) != null ||
+        gl.getRenderbufferParameter(gl.RENDERBUFFER, gl.RENDERBUFFER_WIDTH) != null ||
+        gl.getShaderInfoLog(shader) != null ||
+        gl.getShaderParameter(shader, gl.SHADER_TYPE) != null ||
+        gl.getShaderSource(shader) != null ||
+        gl.getTexParameter(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S) != null ||
+        gl.getUniform(program, uniformLocation) != null ||
+        gl.getUniformLocation(program, 'vPosition') != null ||
+        gl.getVertexAttrib(0, gl.VERTEX_ATTRIB_ARRAY_BUFFER_BINDING) != null ||
+        gl.getSupportedExtensions() != null ||
+        gl.getExtension("WEBGL_lose_context") != null)
+        return false;
+
+    // "Is" queries should all return false.
+    if (gl.isBuffer(buffer) || gl.isEnabled(gl.BLEND) || gl.isFramebuffer(framebuffer) ||
+        gl.isProgram(program) || gl.isRenderbuffer(renderbuffer) || gl.isShader(shader) ||
+        gl.isTexture(texture))
+        return false;
+
+    if (gl.getError() != gl.NO_ERROR)
+        return false;
+
+    // test extensions
+    if (OES_vertex_array_object) {
+        if (!compareGLError(gl.NO_ERROR, "OES_vertex_array_object.bindVertexArrayOES(vertexArrayObject)") ||
+            !compareGLError(gl.NO_ERROR, "OES_vertex_array_object.isVertexArrayOES(vertexArrayObject)") ||
+            !compareGLError(gl.NO_ERROR, "OES_vertex_array_object.deleteVertexArrayOES(vertexArrayObject)"))
+            return false;
+        if (OES_vertex_array_object.createVertexArrayOES() != null)
+            return false;
+    }
+    return true;
+}
+function testValidContext()
+{
+    if (gl.isContextLost())
+        return false;
+
+    arrayBuffer = new ArrayBuffer(4);
+    arrayBufferView = new Int8Array(arrayBuffer);
+
+    // Generate resources for testing.
+    buffer = gl.createBuffer();
+    gl.bindBuffer(gl.ARRAY_BUFFER, buffer);
+    framebuffer = gl.createFramebuffer();
+    gl.bindFramebuffer(gl.FRAMEBUFFER, framebuffer);
+    program = setupSimpleTextureProgram(gl);
+    renderbuffer = gl.createRenderbuffer();
+    gl.bindRenderbuffer(gl.RENDERBUFFER, renderbuffer);
+    shader = gl.createShader(gl.VERTEX_SHADER);
+    texture = gl.createTexture();
+    gl.bindTexture(gl.TEXTURE_2D, texture);
+    if (gl.getError() != gl.NO_ERROR)
+        return false;
+
+    // Test is queries that will later be false
+    if (!compareGLError(gl.NO_ERROR, "gl.enable(gl.BLEND)"))
+        return false;
+    if (!gl.isBuffer(buffer) || !gl.isEnabled(gl.BLEND) || !gl.isFramebuffer(framebuffer) ||
+        !gl.isProgram(program) || !gl.isRenderbuffer(renderbuffer) || !gl.isShader(shader) ||
+        !gl.isTexture(texture))
+        return false;
+
+    if (OES_vertex_array_object) {
+        vertexArrayObject = OES_vertex_array_object.createVertexArrayOES();
+        if (gl.getError() != gl.NO_ERROR)
+            return false;
+        if (!OES_vertex_array_object.isVertexArrayOES(vertexArrayObject))
+            return false;
+    }
+    return true;
+}
+
+function setupTest()
+{
+    canvas = new OffscreenCanvas(10, 10);
+    gl = canvas.getContext('webgl');
+    WEBGL_lose_context = gl.getExtension("WEBGL_lose_context");
+    if (!WEBGL_lose_context)
+        return false;
+
+    // Try to get a few extensions
+    OES_vertex_array_object = gl.getExtension("OES_vertex_array_object");
+    OES_texture_float = gl.getExtension("OES_texture_float");
+
+    return true;
+}
+
+function testOriginalContext()
+{
+    if (gl.isContextLost())
+        return false;
+    if (gl.getError() != gl.NO_ERROR)
+        return false;
+    return true;
+}
+
+function testLostContext(e)
+{
+    if (contextLostEventFired)
+        return false;
+    contextLostEventFired = true;
+    if (!gl.isContextLost())
+        return false;
+    if (gl.getError() != gl.NO_ERROR)
+        return false;
+    if (allowRestore)
+      e.preventDefault();
+    return true;
+}
+
+function testLosingAndRestoringContext()
+{
+    return new Promise(function(resolve, reject) {
+        if (!setupTest())
+            reject("Test failed");
+
+        canvas.addEventListener("webglcontextlost", function(e) {
+            if (!testLostContext(e))
+              reject("Test failed");
+            // restore the context after this event has exited.
+            setTimeout(function() {
+                if (!compareGLError(gl.NO_ERROR, "WEBGL_lose_context.restoreContext()"))
+                    reject("Test failed");
+                // The context should still be lost. It will not get restored until the
+                // webglrestorecontext event is fired.
+                if (!gl.isContextLost())
+                    reject("Test failed");
+                if (gl.getError() != gl.NO_ERROR)
+                    reject("Test failed");
+                // gl methods should still be no-ops
+                if (!compareGLError(gl.NO_ERROR, "gl.blendFunc(gl.TEXTURE_2D, gl.TEXTURE_CUBE_MAP)"))
+                    reject("Test failed");
+            }, 0);
+        });
+        canvas.addEventListener("webglcontextrestored", function() {
+            if (!testRestoredContext())
+                reject("Test failed");
+            else
+                resolve("Test passed");
+        });
+        allowRestore = true;
+        contextLostEventFired = false;
+        contextRestoredEventFired = false;
+
+        if (!testOriginalContext())
+            reject("Test failed");
+        WEBGL_lose_context.loseContext();
+        // The context should be lost immediately.
+        if (!gl.isContextLost())
+            reject("Test failed");
+        if (gl.getError() != gl.CONTEXT_LOST_WEBGL)
+            reject("Test failed");
+        if (gl.getError() != gl.NO_ERROR)
+            reject("Test failed");
+        // gl methods should be no-ops
+        if (!compareGLError(gl.NO_ERROR, "gl.blendFunc(gl.TEXTURE_2D, gl.TEXTURE_CUBE_MAP)"))
+            reject("Test failed");
+        // but the event should not have been fired.
+        if (contextLostEventFired)
+            reject("Test failed");
+    });
+}
+
+function reGetExtensionAndTestForProperty(gl, name, expectProperty) {
+    var newExtension = gl.getExtension(name);
+    // NOTE: while getting a extension after context lost/restored is allowed to fail
+    // for the purpose the conformance tests it is not.
+    //
+    // Hypothetically the user can switch GPUs live. For example on Windows, install 2 GPUs,
+    // then in the control panen enable 1, disable the others and visa versa. Since the GPUs
+    // have different capabilities one or the other may not support a particlar extension.
+    //
+    // But, for the purpose of the conformance tests the context is expected to restore
+    // on the same GPU and therefore the extensions that succeeded previously should
+    // succeed on restore.
+    if (newExtension == null)
+        return false;
+    if (expectProperty) {
+        if (!(newExtension.webglTestProperty === true))
+            return false;
+    } else {
+        if (!(newExtension.webglTestProperty === undefined))
+            return false;
+    }
+    return newExtension;
+}
+
+
+function testOESTextureFloat() {
+  if (OES_texture_float) {
+    // Extension must still be lost.
+    var tex = gl.createTexture();
+    gl.bindTexture(gl.TEXTURE_2D, tex);
+    if (!compareGLError(gl.INVALID_ENUM, "gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, 1, 1, 0, gl.RGBA, gl.FLOAT, null)"))
+        return false;
+    // Try re-enabling extension
+    OES_texture_float = reGetExtensionAndTestForProperty(gl, "OES_texture_float", false);
+    if (!compareGLError(gl.NO_ERROR, "gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, 1, 1, 0, gl.RGBA, gl.FLOAT, null)"))
+        return false;
+    return true;
+  }
+}
+
+function testOESVertexArrayObject() {
+  if (OES_vertex_array_object) {
+    // Extension must still be lost.
+    if (OES_vertex_array_object.createVertexArrayOES() != null)
+        return false;
+    // Try re-enabling extension
+
+    var old_OES_vertex_array_object = OES_vertex_array_object;
+    OES_vertex_array_object = reGetExtensionAndTestForProperty(gl, "OES_vertex_array_object", false);
+    if (OES_vertex_array_object.createVertexArrayOES() == null)
+        return false;
+    if (old_OES_vertex_array_object.createVertexArrayOES() != null)
+        return false;
+    return true;
+  }
+}
+
+function testExtensions() {
+  if (!testOESTextureFloat() || !testOESVertexArrayObject())
+    return false;
+  return true;
+}
+
+function testRestoredContext()
+{
+    if (contextRestoredEventFired)
+        return false;
+    contextRestoredEventFired = true;
+    if (gl.isContextLost())
+        return false;
+    if (gl.getError() != gl.NO_ERROR)
+        return false;
+
+    if (!testExtensions())
+        return false;
+    return true;
+}
+