Function canFallbackToCssMath

packages/css-data/src/parse-css-value.ts:100–137

(ast: CssNode, syntax: string | undefined)

]);

const canFallbackToCssMath = (ast: CssNode, syntax: string | undefined) => {
  if (syntax === undefined) {
    return false;
  }

  let hasCssNumericType = false;
  try {
    definitionSyntax.walk(definitionSyntax.parse(syntax), (node) => {
      if (
        node.type === "Type" &&
        "name" in node &&
        cssNumericTypeNames.has(node.name)
      ) {
        hasCssNumericType = true;
      }
    });
  } catch {
    return false;
  }
  if (hasCssNumericType === false) {
    return false;
  }

  let hasCssNumericFunction = false;
  let hasUnknownIdentifier = false;
  walk(ast, (node) => {
    if (node.type === "Function" && cssNumericFunctionNames.has(node.name)) {
      hasCssNumericFunction = true;
    }
    if (
      node.type === "Identifier" &&
      cssMathConstants.has(node.name.toLowerCase()) === false
    ) {
      hasUnknownIdentifier = true;
    }
  });
  return hasCssNumericFunction && hasUnknownIdentifier === false;
};

const getSyntaxMatchErrorSyntax = (error: Error | null | undefined) => {
  if (error != null && "syntax" in error && typeof error.syntax === "string") {