description("Series of tests to ensure correct behaviour of composite on a fully transparent color."); var ctx = document.createElement('canvas').getContext('2d'); ctx.globalCompositeOperation = "source-over"; ctx.fillStyle = 'rgba(0,0,0,0)'; ctx.fillRect(0,0,100,100); ctx.save(); ctx.translate(0,100); ctx.scale(1,-1); ctx.fillStyle = 'green'; ctx.fillRect(0,0,100,100); ctx.restore(); var imageData = ctx.getImageData(1, 1, 98, 98); var imgdata = imageData.data; shouldBe("imgdata[4]", "0"); shouldBe("imgdata[5]", "128"); shouldBe("imgdata[6]", "0");