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framer-motion

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A simple and powerful JavaScript animation library

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import { invariant } from 'motion-utils'; import { isNumericalString } from '../../../utils/is-numerical-string.mjs'; import { isCSSVariableToken } from './is-css-variable.mjs'; /** * Parse Framer's special CSS variable format into a CSS token and a fallback. * * ``` * `var(--foo, #fff)` => [`--foo`, '#fff'] * ``` * * @param current */ const splitCSSVariableRegex = // eslint-disable-next-line redos-detector/no-unsafe-regex -- false positive, as it can match a lot of words /^var\(--(?:([\w-]+)|([\w-]+), ?([a-zA-Z\d ()%#.,-]+))\)/u; function parseCSSVariable(current) { const match = splitCSSVariableRegex.exec(current); if (!match) return [,]; const [, token1, token2, fallback] = match; return [`--${token1 !== null && token1 !== void 0 ? token1 : token2}`, fallback]; } const maxDepth = 4; function getVariableValue(current, element, depth = 1) { invariant(depth <= maxDepth, `Max CSS variable fallback depth detected in property "${current}". This may indicate a circular fallback dependency.`); const [token, fallback] = parseCSSVariable(current); // No CSS variable detected if (!token) return; // Attempt to read this CSS variable off the element const resolved = window.getComputedStyle(element).getPropertyValue(token); if (resolved) { const trimmed = resolved.trim(); return isNumericalString(trimmed) ? parseFloat(trimmed) : trimmed; } return isCSSVariableToken(fallback) ? getVariableValue(fallback, element, depth + 1) : fallback; } export { getVariableValue, parseCSSVariable };