comment.ts

/*
 * Copyright (c) 2024, salesforce.com, inc.
 * All rights reserved.
 * SPDX-License-Identifier: MIT
 * For full license text, see the LICENSE file in the repo root or https://opensource.org/licenses/MIT
 */

import { builders as b } from 'estree-toolkit';

import {
    generateConcatenatedTextNodesExpressions,
    isLastConcatenatedNode,
} from '../adjacent-text-nodes';
import type { Comment as IrComment } from '@lwc/template-compiler';
import type { Transformer } from '../types';

export const Comment: Transformer<IrComment> = function Comment(node, cxt) {
    if (cxt.templateOptions.preserveComments) {
        return [b.expressionStatement(b.yieldExpression(b.literal(`<!--${node.value}-->`)))];
    } else {
        const isLastInSeries = isLastConcatenatedNode(cxt);

        // If preserve comments is off, we check if we should flush text content
        // for adjacent text nodes. (If preserve comments is on, then the previous
        // text node already flushed.)
        if (isLastInSeries) {
            return generateConcatenatedTextNodesExpressions(cxt);
        }
        return [];
    }
};