2d.text.drawing.style.letterSpacing.measure.worker.js (2060B)
1 // DO NOT EDIT! This test has been generated by /html/canvas/tools/gentest.py. 2 // OffscreenCanvas test in a worker:2d.text.drawing.style.letterSpacing.measure 3 // Description:Testing letter spacing with different length units 4 // Note: 5 6 importScripts("/resources/testharness.js"); 7 importScripts("/html/canvas/resources/canvas-tests.js"); 8 9 var t = async_test("Testing letter spacing with different length units"); 10 var t_pass = t.done.bind(t); 11 var t_fail = t.step_func(function(reason) { 12 throw reason; 13 }); 14 t.step(function() { 15 16 var canvas = new OffscreenCanvas(100, 50); 17 var ctx = canvas.getContext('2d'); 18 19 _assertSame(ctx.letterSpacing, '0px', "ctx.letterSpacing", "'0px'"); 20 _assertSame(ctx.wordSpacing, '0px', "ctx.wordSpacing", "'0px'"); 21 var width_normal = ctx.measureText('Hello World').width; 22 23 function test_letter_spacing(value, difference_spacing, epsilon) { 24 ctx.letterSpacing = value; 25 _assertSame(ctx.letterSpacing, value, "ctx.letterSpacing", "value"); 26 _assertSame(ctx.wordSpacing, '0px', "ctx.wordSpacing", "'0px'"); 27 width_with_letter_spacing = ctx.measureText('Hello World').width; 28 assert_approx_equals(width_with_letter_spacing, width_normal + difference_spacing, epsilon, "letter spacing doesn't work."); 29 } 30 31 // The first value is the letter Spacing to be set, the second value the 32 // change in length of string 'Hello World', note that there are 11 letters 33 // in 'hello world', so the length difference is always letterSpacing * 11. 34 // and the third value is the acceptable differencee for the length change, 35 // note that unit such as 1cm/1mm doesn't map to an exact pixel value. 36 test_cases = [['3px', 33, 0.1], 37 ['5px', 55, 0.1], 38 ['-2px', -22, 0.1], 39 ['1em', 110, 0.1], 40 ['-0.1em', -11, 0.1], 41 ['1in', 1056, 0.1], 42 ['-0.1cm', -41.65, 0.2], 43 ['-0.6mm', -24.95, 0.2]] 44 45 for (const test_case of test_cases) { 46 test_letter_spacing(test_case[0], test_case[1], test_case[2]); 47 } 48 t.done(); 49 }); 50 done();