@scalar/code-highlight/dist/code/line-numbers.js

Central methods and themes for code highlighting in Scalar projects

import { visit } from 'unist-util-visit';

// ---------------------------------------------------------------------------
// Line Numbering plugin
function isText(element) {
    return element?.type === 'text';
}
function isElement(node) {
    return node?.type === 'element';
}
function textElement(value) {
    return { type: 'text', value };
}
function lineBreak() {
    return { type: 'text', value: '\n' };
}
/**
 * Adds lines to code blocks
 */
function codeBlockLinesPlugin() {
    return (tree) => {
        visit(tree, 'element', (node, _i, parent) => {
            if (parent?.type === 'element' && parent.tagName === 'pre' && node.tagName === 'code') {
                let numLines = 0;
                // Wraps each line in a span
                node.children = addLines(node);
                // Adds a line break to the end of each line
                node.children.forEach((child) => {
                    if (child.type === 'element' && child.tagName === 'span') {
                        const lastChild = child.children[child.children.length - 1];
                        if (lastChild && (!isText(lastChild) || (isText(lastChild) && !hasLineBreak(lastChild)))) {
                            child.children.push(lineBreak());
                            numLines++;
                        }
                    }
                });
                // We need to maintain a count of the total lines to allow space for the labels
                node.properties.style = [`--line-count: ${numLines};`, `--line-digits: ${numLines.toString().length};`];
            }
        });
        // console.log('NUMBER OF LINES IS: ', numLines)
    };
}
/**
 * Adds lines to a node recursively and returns them
 *
 * @param node - The node to add lines to
 * @param lines - The current lines
 * @param copyParent - Whether to copy the parent node to save the original node styles
 */
function addLines(node, lines = [], copyParent) {
    const line = () => lines[lines.length - 1] ?? (lines.push(createLine()) && lines[lines.length - 1]);
    node.children.forEach((child) => {
        if (isText(child) && hasLineBreak(child)) {
            const split = child.value.split(/\n/);
            split.forEach((content, i) => {
                copyParent
                    ? line().children.push({ ...node, children: [textElement(content)] })
                    : line().children.push(textElement(content));
                i !== split.length - 1 && lines.push(createLine());
            });
        }
        else if (isElement(child) && child.children.some(hasLineBreak)) {
            addLines(child, lines, true);
        }
        else {
            line().children.push(child);
        }
    });
    return lines;
}
/**
 * Creates a new line element
 *
 * @param children - The children the line should have initially
 */
function createLine(...children) {
    return {
        type: 'element',
        tagName: 'span',
        properties: { class: ['line'] },
        children,
    };
}
/**
 * Checks if a node has a line break
 *
 * @param node - The node to check
 */
function hasLineBreak(node) {
    return (isText(node) && /\r?\n/.test(node.value)) || (isElement(node) && node.children.some(hasLineBreak));
}

export { codeBlockLinesPlugin, isElement, isText, lineBreak, textElement };