| <!DOCTYPE html> |
| <link rel="help" href="https://drafts.css-houdini.org/css-properties-values-api-1/#dependency-cycles-via-relative-units" /> |
| <meta name="assert" content="This test verifies that reference cycles via units are detected" /> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <script> |
| function register_length(name, inherits=false) { |
| CSS.registerProperty({ |
| name: name, |
| syntax: '<length>', |
| initialValue: '0px', |
| inherits: inherits |
| }); |
| } |
| |
| register_length('--font-size-em'); |
| register_length('--font-size-rem'); |
| register_length('--font-size-ex'); |
| register_length('--font-size-ch'); |
| register_length('--font-size-px'); |
| register_length('--font-size-em-via-var'); |
| register_length('--font-size-rem-via-var'); |
| register_length('--font-size-ex-via-var'); |
| register_length('--font-size-ch-via-var'); |
| register_length('--font-size-em-inherited', true); |
| register_length('--font-size-ex-inherited', true); |
| register_length('--font-size-ch-inherited', true); |
| </script> |
| <style> |
| :root { |
| --unregistered-em: 10em; |
| --unregistered-rem: 10rem; |
| --unregistered-ex: 10ex; |
| --unregistered-ch: 10ch; |
| } |
| |
| :root, #target { |
| --font-size-em: 2em; |
| --font-size-rem: 2rem; |
| --font-size-ex: 2ex; |
| --font-size-ch: 2ch; |
| --font-size-px: 42px; |
| --font-size-em-via-var: var(--unregistered-em); |
| --font-size-rem-via-var: var(--unregistered-rem); |
| --font-size-ex-via-var: var(--unregistered-ex); |
| --font-size-ch-via-var: var(--unregistered-ch); |
| } |
| |
| #parent { |
| --font-size-em-inherited: 4em; |
| --font-size-ex-inherited: 4ex; |
| --font-size-ch-inherited: 4ch; |
| } |
| |
| #target { |
| font-size: 11px; |
| } |
| </style> |
| |
| <div id=parent> |
| <div id=target></div> |
| </div> |
| <div id=ref></div> |
| |
| <script> |
| |
| // Compute a dimension (e.g. 1em) given a certain fontSize. |
| function compute_dimension(dimension, fontSize, element = ref) { |
| try { |
| element.attributeStyleMap.set('font-size', fontSize); |
| element.attributeStyleMap.set('margin-bottom', dimension); |
| return getComputedStyle(element).marginBottom; |
| } finally { |
| element.attributeStyleMap.clear(); |
| } |
| } |
| |
| function assert_property_equals(name, value, element = target) { |
| var computedStyle = getComputedStyle(element); |
| assert_equals(computedStyle.getPropertyValue(name), value); |
| } |
| |
| let unsetFontSize = compute_dimension('1em', 'unset'); |
| |
| add_result_callback(function(){ |
| target.attributeStyleMap.clear(); |
| document.documentElement.attributeStyleMap.clear(); |
| }); |
| |
| test(function() { |
| target.style = 'font-size: var(--font-size-px);'; |
| assert_property_equals('font-size', '42px'); |
| assert_property_equals('--font-size-px', '42px'); |
| }, 'Non-font-dependent variables can be used in font-size'); |
| |
| test(function() { |
| target.style = 'font-size: var(--font-size-em);'; |
| assert_property_equals('font-size', unsetFontSize); |
| assert_property_equals('--font-size-em', '0px'); |
| }, 'Lengths with em units may not be referenced from font-size'); |
| |
| test(function() { |
| target.style = 'font-size: var(--font-size-ex);'; |
| assert_property_equals('font-size', unsetFontSize); |
| assert_property_equals('--font-size-ex', '0px'); |
| }, 'Lengths with ex units may not be referenced from font-size'); |
| |
| test(function() { |
| target.style = 'font-size: var(--font-size-ch);'; |
| assert_property_equals('font-size', unsetFontSize); |
| assert_property_equals('--font-size-ch', '0px'); |
| }, 'Lengths with ch units may not be referenced from font-size'); |
| |
| test(function() { |
| target.style = 'font-size: var(--font-size-rem);'; |
| let expected = compute_dimension('2rem', 'unset', document.documentElement); |
| assert_property_equals('--font-size-rem', expected); |
| assert_property_equals('font-size', expected); |
| }, 'Lengths with rem units may be referenced from font-size on non-root element'); |
| |
| test(function() { |
| let root = document.documentElement; |
| root.style = 'font-size: var(--font-size-rem);'; |
| assert_property_equals('font-size', unsetFontSize, root); |
| assert_property_equals('--font-size-rem', '0px', root); |
| }, 'Lengths with rem units may not be referenced from font-size on root element'); |
| |
| test(function() { |
| target.style = 'font-size: var(--noexist, var(--font-size-em));'; |
| assert_property_equals('font-size', unsetFontSize); |
| }, 'Fallback may not use font-relative units'); |
| |
| test(function() { |
| target.style = 'font-size: var(--font-size-em, 42px);'; |
| assert_property_equals('font-size', unsetFontSize); |
| }, 'Fallback not triggered while inside em unit cycle'); |
| |
| test(function() { |
| target.style = 'font-size: var(--font-size-ex, 42px);'; |
| assert_property_equals('font-size', unsetFontSize); |
| }, 'Fallback not triggered while inside ex unit cycle'); |
| |
| test(function() { |
| target.style = 'font-size: var(--font-size-ch, 42px);'; |
| assert_property_equals('font-size', unsetFontSize); |
| }, 'Fallback not triggered while inside ch unit cycle'); |
| |
| test(function() { |
| let root = document.documentElement; |
| root.style = 'font-size: var(--font-size-rem, 42px);'; |
| assert_property_equals('font-size', unsetFontSize, root); |
| root.style = 'font-size: unset;'; |
| }, 'Fallback not triggered while inside rem unit cycle on root element'); |
| |
| test(function() { |
| target.style = 'font-size: var(--font-size-em-via-var);'; |
| assert_property_equals('font-size', unsetFontSize); |
| assert_property_equals('--font-size-em-via-var', '0px'); |
| }, 'Lengths with em units are detected via var references'); |
| |
| test(function() { |
| target.style = 'font-size: var(--font-size-ex-via-var);'; |
| assert_property_equals('font-size', unsetFontSize); |
| assert_property_equals('--font-size-ex-via-var', '0px'); |
| }, 'Lengths with ex units are detected via var references'); |
| |
| test(function() { |
| target.style = 'font-size: var(--font-size-ch-via-var);'; |
| assert_property_equals('font-size', unsetFontSize); |
| assert_property_equals('--font-size-ch-via-var', '0px'); |
| }, 'Lengths with ch units are detected via var references'); |
| |
| test(function() { |
| let root = document.documentElement; |
| root.style = 'font-size: var(--font-size-rem-via-var);'; |
| assert_property_equals('font-size', unsetFontSize, root); |
| assert_property_equals('--font-size-rem-via-var', '0px', root); |
| root.style = 'font-size: unset'; |
| }, 'Lengths with rem units are detected via var references'); |
| |
| test(function() { |
| let expected4em = compute_dimension('4em', 'unset'); |
| target.style = 'font-size: var(--font-size-em-inherited);'; |
| assert_property_equals('font-size', expected4em); |
| assert_property_equals('--font-size-em-inherited', expected4em); |
| }, 'Inherited lengths with em units may be used'); |
| |
| test(function() { |
| let expected4ex = compute_dimension('4ex', 'unset'); |
| target.style = 'font-size: var(--font-size-ex-inherited);'; |
| assert_property_equals('font-size', expected4ex); |
| assert_property_equals('--font-size-ex-inherited', expected4ex); |
| }, 'Inherited lengths with ex units may be used'); |
| |
| test(function() { |
| let expected4ch = compute_dimension('4ch', 'unset'); |
| target.style = 'font-size: var(--font-size-ch-inherited);'; |
| assert_property_equals('font-size', expected4ch); |
| assert_property_equals('--font-size-ch-inherited', expected4ch); |
| }, 'Inherited lengths with ch units may be used'); |
| |
| </script> |