@stylistic/stylelint-plugin/lib/utils/isStandardSyntaxFunction/index.js

A collection of stylistic/formatting Stylelint rules

/**
 * Check whether a function is standard
 *
 * @param {import('postcss-value-parser').Node} node
 * @returns {boolean}
 */
export function isStandardSyntaxFunction (node) {
	// Function nodes without names are things in parentheses like Sass lists
	if (!node.value) {
		return false
	}

	if (node.value.startsWith(`#{`)) {
		return false
	}

	// CSS-in-JS interpolation
	if (node.value.startsWith(`\${`)) {
		return false
	}

	// CSS-in-JS syntax
	if (node.value.startsWith(`\``)) {
		return false
	}

	return true
}