| import { | |
| walk, | |
| generate, | |
| property as resolveProperty, | |
| keyword as resolveKeyword | |
| } from 'css-tree'; | |
| let fingerprintId = 1; | |
| const dontRestructure = new Set([ | |
| 'src' // https://github.com/afelix/csso/issues/50 | |
| ]); | |
| const DONT_MIX_VALUE = { | |
| // https://developer.mozilla.org/en-US/docs/Web/CSS/display#Browser_compatibility | |
| 'display': /table|ruby|flex|-(flex)?box$|grid|contents|run-in/i, | |
| // https://developer.mozilla.org/en/docs/Web/CSS/text-align | |
| 'text-align': /^(start|end|match-parent|justify-all)$/i | |
| }; | |
| const SAFE_VALUES = { | |
| cursor: [ | |
| 'auto', 'crosshair', 'default', 'move', 'text', 'wait', 'help', | |
| 'n-resize', 'e-resize', 's-resize', 'w-resize', | |
| 'ne-resize', 'nw-resize', 'se-resize', 'sw-resize', | |
| 'pointer', 'progress', 'not-allowed', 'no-drop', 'vertical-text', 'all-scroll', | |
| 'col-resize', 'row-resize' | |
| ], | |
| overflow: [ | |
| 'hidden', 'visible', 'scroll', 'auto' | |
| ], | |
| position: [ | |
| 'static', 'relative', 'absolute', 'fixed' | |
| ] | |
| }; | |
| const NEEDLESS_TABLE = { | |
| 'border-width': ['border'], | |
| 'border-style': ['border'], | |
| 'border-color': ['border'], | |
| 'border-top': ['border'], | |
| 'border-right': ['border'], | |
| 'border-bottom': ['border'], | |
| 'border-left': ['border'], | |
| 'border-top-width': ['border-top', 'border-width', 'border'], | |
| 'border-right-width': ['border-right', 'border-width', 'border'], | |
| 'border-bottom-width': ['border-bottom', 'border-width', 'border'], | |
| 'border-left-width': ['border-left', 'border-width', 'border'], | |
| 'border-top-style': ['border-top', 'border-style', 'border'], | |
| 'border-right-style': ['border-right', 'border-style', 'border'], | |
| 'border-bottom-style': ['border-bottom', 'border-style', 'border'], | |
| 'border-left-style': ['border-left', 'border-style', 'border'], | |
| 'border-top-color': ['border-top', 'border-color', 'border'], | |
| 'border-right-color': ['border-right', 'border-color', 'border'], | |
| 'border-bottom-color': ['border-bottom', 'border-color', 'border'], | |
| 'border-left-color': ['border-left', 'border-color', 'border'], | |
| 'margin-top': ['margin'], | |
| 'margin-right': ['margin'], | |
| 'margin-bottom': ['margin'], | |
| 'margin-left': ['margin'], | |
| 'padding-top': ['padding'], | |
| 'padding-right': ['padding'], | |
| 'padding-bottom': ['padding'], | |
| 'padding-left': ['padding'], | |
| 'font-style': ['font'], | |
| 'font-variant': ['font'], | |
| 'font-weight': ['font'], | |
| 'font-size': ['font'], | |
| 'font-family': ['font'], | |
| 'list-style-type': ['list-style'], | |
| 'list-style-position': ['list-style'], | |
| 'list-style-image': ['list-style'] | |
| }; | |
| function getPropertyFingerprint(propertyName, declaration, fingerprints) { | |
| const realName = resolveProperty(propertyName).basename; | |
| if (realName === 'background') { | |
| return propertyName + ':' + generate(declaration.value); | |
| } | |
| const declarationId = declaration.id; | |
| let fingerprint = fingerprints[declarationId]; | |
| if (!fingerprint) { | |
| switch (declaration.value.type) { | |
| case 'Value': | |
| const special = {}; | |
| let vendorId = ''; | |
| let iehack = ''; | |
| let raw = false; | |
| declaration.value.children.forEach(function walk(node) { | |
| switch (node.type) { | |
| case 'Value': | |
| case 'Brackets': | |
| case 'Parentheses': | |
| node.children.forEach(walk); | |
| break; | |
| case 'Raw': | |
| raw = true; | |
| break; | |
| case 'Identifier': { | |
| const { name } = node; | |
| if (!vendorId) { | |
| vendorId = resolveKeyword(name).vendor; | |
| } | |
| if (/\\[09]/.test(name)) { | |
| iehack = RegExp.lastMatch; | |
| } | |
| if (SAFE_VALUES.hasOwnProperty(realName)) { | |
| if (SAFE_VALUES[realName].indexOf(name) === -1) { | |
| special[name] = true; | |
| } | |
| } else if (DONT_MIX_VALUE.hasOwnProperty(realName)) { | |
| if (DONT_MIX_VALUE[realName].test(name)) { | |
| special[name] = true; | |
| } | |
| } | |
| break; | |
| } | |
| case 'Function': { | |
| let { name } = node; | |
| if (!vendorId) { | |
| vendorId = resolveKeyword(name).vendor; | |
| } | |
| if (name === 'rect') { | |
| // there are 2 forms of rect: | |
| // rect(<top>, <right>, <bottom>, <left>) - standart | |
| // rect(<top> <right> <bottom> <left>) – backwards compatible syntax | |
| // only the same form values can be merged | |
| const hasComma = node.children.some((node) => | |
| node.type === 'Operator' && node.value === ',' | |
| ); | |
| if (!hasComma) { | |
| name = 'rect-backward'; | |
| } | |
| } | |
| special[name + '()'] = true; | |
| // check nested tokens too | |
| node.children.forEach(walk); | |
| break; | |
| } | |
| case 'Dimension': { | |
| const { unit } = node; | |
| if (/\\[09]/.test(unit)) { | |
| iehack = RegExp.lastMatch; | |
| } | |
| switch (unit) { | |
| // is not supported until IE11 | |
| case 'rem': | |
| // v* units is too buggy across browsers and better | |
| // don't merge values with those units | |
| case 'vw': | |
| case 'vh': | |
| case 'vmin': | |
| case 'vmax': | |
| case 'vm': // IE9 supporting "vm" instead of "vmin". | |
| special[unit] = true; | |
| break; | |
| } | |
| break; | |
| } | |
| } | |
| }); | |
| fingerprint = raw | |
| ? '!' + fingerprintId++ | |
| : '!' + Object.keys(special).sort() + '|' + iehack + vendorId; | |
| break; | |
| case 'Raw': | |
| fingerprint = '!' + declaration.value.value; | |
| break; | |
| default: | |
| fingerprint = generate(declaration.value); | |
| } | |
| fingerprints[declarationId] = fingerprint; | |
| } | |
| return propertyName + fingerprint; | |
| } | |
| function needless(props, declaration, fingerprints) { | |
| const property = resolveProperty(declaration.property); | |
| if (NEEDLESS_TABLE.hasOwnProperty(property.basename)) { | |
| const table = NEEDLESS_TABLE[property.basename]; | |
| for (const entry of table) { | |
| const ppre = getPropertyFingerprint(property.prefix + entry, declaration, fingerprints); | |
| const prev = props.hasOwnProperty(ppre) ? props[ppre] : null; | |
| if (prev && (!declaration.important || prev.item.data.important)) { | |
| return prev; | |
| } | |
| } | |
| } | |
| } | |
| function processRule(rule, item, list, props, fingerprints) { | |
| const declarations = rule.block.children; | |
| declarations.forEachRight(function(declaration, declarationItem) { | |
| const { property } = declaration; | |
| const fingerprint = getPropertyFingerprint(property, declaration, fingerprints); | |
| const prev = props[fingerprint]; | |
| if (prev && !dontRestructure.has(property)) { | |
| if (declaration.important && !prev.item.data.important) { | |
| props[fingerprint] = { | |
| block: declarations, | |
| item: declarationItem | |
| }; | |
| prev.block.remove(prev.item); | |
| // TODO: use it when we can refer to several points in source | |
| // declaration.loc = { | |
| // primary: declaration.loc, | |
| // merged: prev.item.data.loc | |
| // }; | |
| } else { | |
| declarations.remove(declarationItem); | |
| // TODO: use it when we can refer to several points in source | |
| // prev.item.data.loc = { | |
| // primary: prev.item.data.loc, | |
| // merged: declaration.loc | |
| // }; | |
| } | |
| } else { | |
| const prev = needless(props, declaration, fingerprints); | |
| if (prev) { | |
| declarations.remove(declarationItem); | |
| // TODO: use it when we can refer to several points in source | |
| // prev.item.data.loc = { | |
| // primary: prev.item.data.loc, | |
| // merged: declaration.loc | |
| // }; | |
| } else { | |
| declaration.fingerprint = fingerprint; | |
| props[fingerprint] = { | |
| block: declarations, | |
| item: declarationItem | |
| }; | |
| } | |
| } | |
| }); | |
| if (declarations.isEmpty) { | |
| list.remove(item); | |
| } | |
| } | |
| export default function restructBlock(ast) { | |
| const stylesheetMap = {}; | |
| const fingerprints = Object.create(null); | |
| walk(ast, { | |
| visit: 'Rule', | |
| reverse: true, | |
| enter(node, item, list) { | |
| const stylesheet = this.block || this.stylesheet; | |
| const ruleId = (node.pseudoSignature || '') + '|' + node.prelude.children.first.id; | |
| let ruleMap; | |
| let props; | |
| if (!stylesheetMap.hasOwnProperty(stylesheet.id)) { | |
| ruleMap = {}; | |
| stylesheetMap[stylesheet.id] = ruleMap; | |
| } else { | |
| ruleMap = stylesheetMap[stylesheet.id]; | |
| } | |
| if (ruleMap.hasOwnProperty(ruleId)) { | |
| props = ruleMap[ruleId]; | |
| } else { | |
| props = {}; | |
| ruleMap[ruleId] = props; | |
| } | |
| processRule.call(this, node, item, list, props, fingerprints); | |
| } | |
| }); | |
| }; |