Test the WebGL premultipledAlpha context creation flag. On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE". testing: premultipliedAlpha: true imageFormat: image/png PASS gl.getContextAttributes().premultipledAlpha is premultipledAlpha PASS gl.getContextAttributes().preserveDrawingBuffer is true PASS getError was expected value: NO_ERROR : Should be no errors from setup. PASS getError was expected value: NO_ERROR : Should be no errors from drawing. PASS getError was expected value: NO_ERROR : Should be no errors from creating copy. PASS getError was expected value: NO_ERROR : Should be no errors from 2nd drawing. PASS should draw with 64,128,255,128 testing: premultipliedAlpha: true imageFormat: undefined PASS gl.getContextAttributes().premultipledAlpha is premultipledAlpha PASS gl.getContextAttributes().preserveDrawingBuffer is true PASS getError was expected value: NO_ERROR : Should be no errors from setup. PASS getError was expected value: NO_ERROR : Should be no errors from drawing. PASS getError was expected value: NO_ERROR : Should be no errors from creating copy. PASS getError was expected value: NO_ERROR : Should be no errors from 2nd drawing. PASS should draw with 64,128,255,128 testing: premultipliedAlpha: false imageFormat: image/png PASS gl.getContextAttributes().premultipledAlpha is premultipledAlpha PASS gl.getContextAttributes().preserveDrawingBuffer is true PASS getError was expected value: NO_ERROR : Should be no errors from setup. PASS getError was expected value: NO_ERROR : Should be no errors from drawing. PASS getError was expected value: NO_ERROR : Should be no errors from creating copy. PASS getError was expected value: NO_ERROR : Should be no errors from 2nd drawing. FAIL should draw with 255,192,128,1 at (0, 0) expected: 255,192,128,1 was 255,0,0,1 testing: premultipliedAlpha: false imageFormat: undefined PASS gl.getContextAttributes().premultipledAlpha is premultipledAlpha PASS gl.getContextAttributes().preserveDrawingBuffer is true PASS getError was expected value: NO_ERROR : Should be no errors from setup. PASS getError was expected value: NO_ERROR : Should be no errors from drawing. PASS getError was expected value: NO_ERROR : Should be no errors from creating copy. PASS getError was expected value: NO_ERROR : Should be no errors from 2nd drawing. PASS should draw with 255,192,128,1 testing: premultipliedAlpha: false imageFormat: image/jpeg PASS gl.getContextAttributes().premultipledAlpha is premultipledAlpha PASS gl.getContextAttributes().preserveDrawingBuffer is true PASS getError was expected value: NO_ERROR : Should be no errors from setup. PASS getError was expected value: NO_ERROR : Should be no errors from drawing. PASS getError was expected value: NO_ERROR : Should be no errors from creating copy. PASS getError was expected value: NO_ERROR : Should be no errors from 2nd drawing. PASS should draw with 128,128,128,255 testing: premultipliedAlpha: true imageFormat: image/jpeg PASS gl.getContextAttributes().premultipledAlpha is premultipledAlpha PASS gl.getContextAttributes().preserveDrawingBuffer is true PASS getError was expected value: NO_ERROR : Should be no errors from setup. PASS getError was expected value: NO_ERROR : Should be no errors from drawing. PASS getError was expected value: NO_ERROR : Should be no errors from creating copy. PASS getError was expected value: NO_ERROR : Should be no errors from 2nd drawing. PASS should draw with 128,128,128,255 PASS successfullyParsed is true Some tests failed. TEST COMPLETE