Verify WebGLContextAttributes are working as specified, including alpha, depth, stencil, antialias, but not premultipliedAlpha

On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".

Testing alpha = true
PASS getError was expected value: NO_ERROR : should be no errors
PASS gl = getWebGL(1, 1, { alpha: true, depth: false, stencil: false, antialias: false }, [ 0, 0, 0, 0 ], 1, 0) is non-null.
PASS gl.getParameter(gl.ALPHA_BITS) >= 8 is true
PASS gl.getParameter(gl.RED_BITS) >= 8 is true
PASS gl.getParameter(gl.GREEN_BITS) >= 8 is true
PASS gl.getParameter(gl.BLUE_BITS) >= 8 is true
PASS gl.getParameter(gl.DEPTH_BITS) == 0 is true
PASS gl.getParameter(gl.STENCIL_BITS) == 0 is true
PASS contextAttribs = gl.getContextAttributes() is non-null.
PASS contextAttribs.alpha == true is true
PASS pixel is correctColor
PASS Math.abs(pixel[0] - 127) <= 1 && Math.abs(pixel[1] - 127) <= 1 && Math.abs(pixel[2] - 127) <= 1 && Math.abs(pixel[3] - 127) <= 1 is true
Testing alpha = false
PASS getError was expected value: NO_ERROR : should be no errors
PASS gl = getWebGL(1, 1, { alpha: false, depth: false, stencil: false, antialias: false }, [ 0, 0, 0, 0 ], 1, 0) is non-null.
PASS gl.getParameter(gl.ALPHA_BITS) == 0 is true
PASS gl.getParameter(gl.RED_BITS) >= 8 is true
PASS gl.getParameter(gl.GREEN_BITS) >= 8 is true
PASS gl.getParameter(gl.BLUE_BITS) >= 8 is true
PASS gl.getParameter(gl.DEPTH_BITS) == 0 is true
PASS gl.getParameter(gl.STENCIL_BITS) == 0 is true
PASS contextAttribs = gl.getContextAttributes() is non-null.
PASS contextAttribs.alpha == false is true
PASS pixel is correctColor
PASS Math.abs(pixel[0] - 127) <= 1 && Math.abs(pixel[1] - 127) <= 1 && Math.abs(pixel[2] - 127) <= 1 && Math.abs(pixel[3] - 127) <= 1 is true
Testing depth = true
PASS getError was expected value: NO_ERROR : should be no errors
PASS gl = getWebGL(1, 1, { depth: true, stencil: false, antialias: false }, [ 0, 0, 0, 1 ], 1, 0) is non-null.
PASS gl.getParameter(gl.DEPTH_BITS) >= 16 is true
PASS gl.getParameter(gl.RED_BITS) >= 8 is true
PASS gl.getParameter(gl.GREEN_BITS) >= 8 is true
PASS gl.getParameter(gl.BLUE_BITS) >= 8 is true
PASS gl.getParameter(gl.ALPHA_BITS) >= 8 is true
PASS contextAttribs = gl.getContextAttributes() is non-null.
PASS pixel is correctColor
PASS pixel is [0, 0, 0, 255]
Testing depth = false
PASS getError was expected value: NO_ERROR : should be no errors
PASS gl = getWebGL(1, 1, { depth: false, stencil: false, antialias: false }, [ 0, 0, 0, 1 ], 1, 0) is non-null.
PASS gl.getParameter(gl.DEPTH_BITS) == 0 is true
PASS gl.getParameter(gl.RED_BITS) >= 8 is true
PASS gl.getParameter(gl.GREEN_BITS) >= 8 is true
PASS gl.getParameter(gl.BLUE_BITS) >= 8 is true
PASS gl.getParameter(gl.ALPHA_BITS) >= 8 is true
PASS contextAttribs = gl.getContextAttributes() is non-null.
PASS pixel is correctColor
PASS pixel is [0, 0, 0, 255]
Testing stencil = true, depth = false
PASS getError was expected value: NO_ERROR : should be no errors
PASS gl = getWebGL(1, 1, { depth: false, stencil: true, antialias: false }, [ 0, 0, 0, 1 ], 1, 0) is non-null.
PASS gl.getParameter(gl.RED_BITS) >= 8 is true
PASS gl.getParameter(gl.GREEN_BITS) >= 8 is true
PASS gl.getParameter(gl.BLUE_BITS) >= 8 is true
PASS gl.getParameter(gl.ALPHA_BITS) >= 8 is true
PASS gl.getParameter(gl.DEPTH_BITS) == 0 is true
PASS gl.getParameter(gl.STENCIL_BITS) >= 8 is true
PASS contextAttribs = gl.getContextAttributes() is non-null.
PASS pixel is correctColor
PASS pixel is [0, 0, 0, 255]
Testing stencil = false, depth = false
PASS getError was expected value: NO_ERROR : should be no errors
PASS gl = getWebGL(1, 1, { depth: false, stencil: false, antialias: false }, [ 0, 0, 0, 1 ], 1, 0) is non-null.
PASS gl.getParameter(gl.RED_BITS) >= 8 is true
PASS gl.getParameter(gl.GREEN_BITS) >= 8 is true
PASS gl.getParameter(gl.BLUE_BITS) >= 8 is true
PASS gl.getParameter(gl.ALPHA_BITS) >= 8 is true
PASS gl.getParameter(gl.DEPTH_BITS) == 0 is true
PASS gl.getParameter(gl.STENCIL_BITS) == 0 is true
PASS contextAttribs = gl.getContextAttributes() is non-null.
PASS pixel is correctColor
PASS pixel is [0, 0, 0, 255]
Testing stencil = true, depth = true
PASS getError was expected value: NO_ERROR : should be no errors
PASS gl = getWebGL(1, 1, { depth: true, stencil: true, antialias: false }, [ 0, 0, 0, 1 ], 1, 0) is non-null.
PASS gl.getParameter(gl.RED_BITS) >= 8 is true
PASS gl.getParameter(gl.GREEN_BITS) >= 8 is true
PASS gl.getParameter(gl.BLUE_BITS) >= 8 is true
PASS gl.getParameter(gl.ALPHA_BITS) >= 8 is true
PASS gl.getParameter(gl.DEPTH_BITS) >= 16 is true
PASS gl.getParameter(gl.STENCIL_BITS) >= 8 is true
PASS contextAttribs = gl.getContextAttributes() is non-null.
PASS pixel is correctColor
PASS pixel is [0, 0, 0, 255]
Testing stencil = false, depth = true
PASS getError was expected value: NO_ERROR : should be no errors
PASS gl = getWebGL(1, 1, { depth: true, stencil: false, antialias: false }, [ 0, 0, 0, 1 ], 1, 0) is non-null.
PASS gl.getParameter(gl.RED_BITS) >= 8 is true
PASS gl.getParameter(gl.GREEN_BITS) >= 8 is true
PASS gl.getParameter(gl.BLUE_BITS) >= 8 is true
PASS gl.getParameter(gl.ALPHA_BITS) >= 8 is true
PASS gl.getParameter(gl.DEPTH_BITS) >= 16 is true
PASS gl.getParameter(gl.STENCIL_BITS) == 0 is true
PASS contextAttribs = gl.getContextAttributes() is non-null.
PASS pixel is correctColor
PASS pixel is [0, 0, 0, 255]
Testing antialias = true
PASS getError was expected value: NO_ERROR : should be no errors
PASS gl = getWebGL(2, 2, { depth: false, stencil: false, alpha: false, antialias: true }, [ 0, 0, 0, 1 ], 1, 0) is non-null.
PASS contextAttribs = gl.getContextAttributes() is non-null.
PASS pixel[0] != 255 && pixel[0] != 0 is contextAttribs.antialias
Testing antialias = false
PASS getError was expected value: NO_ERROR : should be no errors
PASS gl = getWebGL(2, 2, { depth: false, stencil: false, alpha: false, antialias: false }, [ 0, 0, 0, 1 ], 1, 0) is non-null.
PASS contextAttribs = gl.getContextAttributes() is non-null.
PASS pixel[0] != 255 && pixel[0] != 0 is contextAttribs.antialias
Testing default values for attributes
Testing default alpha = true
PASS getError was expected value: NO_ERROR : should be no errors
PASS gl = getWebGL(1, 1, { depth: false, stencil: false, antialias: false }, [ 0, 0, 0, 0 ], 1, 0) is non-null.
PASS gl.getParameter(gl.ALPHA_BITS) >= 8 is true
PASS gl.getParameter(gl.RED_BITS) >= 8 is true
PASS gl.getParameter(gl.GREEN_BITS) >= 8 is true
PASS gl.getParameter(gl.BLUE_BITS) >= 8 is true
PASS gl.getParameter(gl.DEPTH_BITS) == 0 is true
PASS gl.getParameter(gl.STENCIL_BITS) == 0 is true
PASS contextAttribs = gl.getContextAttributes() is non-null.
PASS contextAttribs.alpha == true is true
PASS pixel is correctColor
PASS Math.abs(pixel[0] - 127) <= 1 && Math.abs(pixel[1] - 127) <= 1 && Math.abs(pixel[2] - 127) <= 1 && Math.abs(pixel[3] - 127) <= 1 is true
Testing default depth = true
PASS getError was expected value: NO_ERROR : should be no errors
PASS gl = getWebGL(1, 1, { stencil: false, antialias: false }, [ 0, 0, 0, 1 ], 1, 0) is non-null.
PASS gl.getParameter(gl.DEPTH_BITS) >= 16 is true
PASS gl.getParameter(gl.RED_BITS) >= 8 is true
PASS gl.getParameter(gl.GREEN_BITS) >= 8 is true
PASS gl.getParameter(gl.BLUE_BITS) >= 8 is true
PASS gl.getParameter(gl.ALPHA_BITS) >= 8 is true
PASS contextAttribs = gl.getContextAttributes() is non-null.
PASS pixel is correctColor
PASS pixel is [0, 0, 0, 255]
Testing default stencil = false and default depth = true
PASS getError was expected value: NO_ERROR : should be no errors
PASS gl = getWebGL(1, 1, { antialias: false }, [ 0, 0, 0, 1 ], 1, 0) is non-null.
PASS gl.getParameter(gl.RED_BITS) >= 8 is true
PASS gl.getParameter(gl.GREEN_BITS) >= 8 is true
PASS gl.getParameter(gl.BLUE_BITS) >= 8 is true
PASS gl.getParameter(gl.ALPHA_BITS) >= 8 is true
PASS gl.getParameter(gl.DEPTH_BITS) >= 16 is true
PASS gl.getParameter(gl.STENCIL_BITS) == 0 is true
PASS contextAttribs = gl.getContextAttributes() is non-null.
PASS pixel is correctColor
PASS pixel is [0, 0, 0, 255]
Testing default antialias = true
PASS getError was expected value: NO_ERROR : should be no errors
PASS gl = getWebGL(2, 2, { depth: false, stencil: false, alpha: false }, [ 0, 0, 0, 1 ], 1, 0) is non-null.
PASS contextAttribs = gl.getContextAttributes() is non-null.
PASS pixel[0] != 255 && pixel[0] != 0 is contextAttribs.antialias
PASS successfullyParsed is true

TEST COMPLETE