css-tree/lib/syntax/function/var.js

A tool set for CSS: fast detailed parser (CSS → AST), walker (AST traversal), generator (AST → CSS) and lexer (validation and matching) based on specs and browser implementations

import { Comma, WhiteSpace } from '../../tokenizer/index.js';

// var( <ident> , <value>? )
export default function() {
    const children = this.createList();

    this.skipSC();

    // NOTE: Don't check more than a first argument is an ident, rest checks are for lexer
    children.push(this.Identifier());

    this.skipSC();

    if (this.tokenType === Comma) {
        children.push(this.Operator());

        const startIndex = this.tokenIndex;
        const value = this.parseCustomProperty
            ? this.Value(null)
            : this.Raw(this.consumeUntilExclamationMarkOrSemicolon, false);

        if (value.type === 'Value' && value.children.isEmpty) {
            for (let offset = startIndex - this.tokenIndex; offset <= 0; offset++) {
                if (this.lookupType(offset) === WhiteSpace) {
                    value.children.appendData({
                        type: 'WhiteSpace',
                        loc: null,
                        value: ' '
                    });
                    break;
                }
            }
        }

        children.push(value);
    }

    return children;
};