@wix/css-property-parser
Version:
A comprehensive TypeScript library for parsing and serializing CSS property values with full MDN specification compliance
139 lines (138 loc) • 5.2 kB
JavaScript
"use strict";
// Line-height property parser
// Handles parsing of CSS line-height property according to MDN specification
// https://developer.mozilla.org/en-US/docs/Web/CSS/line-height
Object.defineProperty(exports, "__esModule", { value: true });
exports.parse = parse;
exports.toCSSValue = toCSSValue;
const number_1 = require('./number.cjs');
const length_1 = require('./length.cjs');
const percentage_1 = require('./percentage.cjs');
const css_variable_1 = require('./css-variable.cjs');
const shared_utils_1 = require('../utils/shared-utils.cjs');
/**
* Check if a value is a valid line-height keyword
*/
function isLineHeightKeyword(value) {
const keyword = value.toLowerCase();
return keyword === 'normal';
}
/**
* Parses a CSS line-height property string into structured components
* Follows MDN specification: https://developer.mozilla.org/en-US/docs/Web/CSS/line-height
*/
function parse(value) {
if (!value || typeof value !== 'string') {
return null;
}
const trimmed = value.trim();
if (trimmed === '') {
return null;
}
// CSS variables can be parsed directly
if ((0, shared_utils_1.isCssVariable)(trimmed)) {
return (0, css_variable_1.parse)(trimmed);
}
// Handle global keywords (inherit, initial, unset, revert, revert-layer)
if ((0, shared_utils_1.isGlobalKeyword)(trimmed)) {
return { type: 'keyword', keyword: trimmed.toLowerCase() };
}
// Handle line-height keywords (normal)
if (isLineHeightKeyword(trimmed)) {
return { type: 'keyword', keyword: trimmed.toLowerCase() };
}
// Try to parse as number first (unitless multiplier) - includes calc() expressions
const numberResult = (0, number_1.parse)(trimmed);
if (numberResult) {
// Handle CSS variables from number parser
if ('CSSvariable' in numberResult) {
return numberResult;
}
// Check for non-negative values
if ('value' in numberResult && numberResult.value < 0) {
return null;
}
// Return as LineHeightNumber or function expression
if ('value' in numberResult) {
return { type: 'number', value: numberResult.value };
}
// Handle calc expressions (NumberCalcExpression)
if ('expression' in numberResult) {
return { expression: numberResult.expression, function: numberResult.function };
}
}
// Try to parse as percentage - includes calc() expressions
const percentageResult = (0, percentage_1.parse)(trimmed);
if (percentageResult) {
// Handle CSS variables from percentage parser
if ('CSSvariable' in percentageResult) {
return percentageResult;
}
// Check for non-negative values
if ('value' in percentageResult && percentageResult.value < 0) {
return null;
}
// Return as LineHeightPercentage or function expression
if ('value' in percentageResult) {
return { type: 'percentage', value: percentageResult.value, unit: '%' };
}
// Handle calc expressions (PercentageCalcExpression)
if ('expression' in percentageResult) {
return { expression: percentageResult.expression, function: percentageResult.function };
}
}
// Try to parse as length - includes calc() expressions
const lengthResult = (0, length_1.parse)(trimmed);
if (lengthResult) {
// Handle CSS variables from length parser
if ('CSSvariable' in lengthResult) {
return lengthResult;
}
// Check for non-negative values
if ('value' in lengthResult && lengthResult.value < 0) {
return null;
}
// Return as LineHeightLength or function expression
if ('value' in lengthResult) {
return { type: 'length', value: lengthResult.value, unit: lengthResult.unit };
}
// Handle calc expressions (LengthCalcExpression)
if ('expression' in lengthResult) {
return { expression: lengthResult.expression, function: lengthResult.function };
}
}
return null;
}
/**
* Converts a parsed line-height back to a CSS value string
*/
function toCSSValue(parsed) {
if (!parsed) {
return null;
}
// Handle CSS variables
if ('CSSvariable' in parsed) {
return (0, css_variable_1.toCSSValue)(parsed);
}
// Handle keyword values
if ('keyword' in parsed) {
return parsed.keyword;
}
// Handle function expressions
if ('expression' in parsed && 'function' in parsed) {
return `${parsed.function}(${parsed.expression})`;
}
// Handle numeric values (LineHeightNumber)
if ('value' in parsed && !('unit' in parsed)) {
return parsed.value.toString();
}
// Handle length values (LineHeightLength)
if ('value' in parsed && 'unit' in parsed && parsed.unit !== '%') {
return `${parsed.value}${parsed.unit}`;
}
// Handle percentage values (LineHeightPercentage)
if ('value' in parsed && 'unit' in parsed && parsed.unit === '%') {
return `${parsed.value}%`;
}
return null;
}