An example of 'Markdown formatter' macro for VSCodeMacros extension

MarkdownFormatter.js

// [VSCode Macros] extension
// https://marketplace.visualstudio.com/items?itemName=EXCEEDSYSTEM.vscode-macros
// License:MIT
const vscode = require('vscode');
const remark = require('remark'); // Requires version 13 or above
const remarkParse = require('remark-parse');
const remarkStringify = require('remark-stringify');
const remarkGFM = require('remark-gfm');
const remarkFrontmatter = require('remark-frontmatter'); // Requires version 3 or above

module.exports.macroCommands = {
    FormatMarkdown: {
        no: 1,
        func: formatMD,
    },
};

function formatMD() {
    const editor = vscode.window.activeTextEditor;
    if (!editor) {
        vscode.window.showWarningMessage('Editor not found.');
        return;
    }
    const document = editor.document;
    if (!document) {
        vscode.window.showWarningMessage('Document not found.');
        return;
    }
    if (document.languageId !== 'markdown') {
        vscode.window.showWarningMessage(`This document type '${document.languageId}' is not supported.`);
        return;
    }

    // Get east asian ambiguous characters
    const eastAsianAmbiguous = Array.from('μ').map(s => s.codePointAt(0));
    // Markdown formatting options(https://github.com/syntax-tree/mdast-util-to-markdown#formatting-options)
    const remarksOptions = {
        bullet: '-',
        listItemIndent: 'one',
        rule: '-'
    };

    const srcMarkdown = document.getText();
    // Convert markdown text to the syntax tree
    const mdNode = remark()
        .use(remarkGFM)
        .use(remarkParse)
        .use(remarkFrontmatter)
        .parse(srcMarkdown);
    // Convert the syntax tree to markdown text
    const dstMarkdown = remark()
        .use(remarkGFM, {
            // Calculate the number of characters in a cell
            stringLength: (s) => {
                let len = 0;
                Array.from(s).forEach((elem) => {
                    let cpv;
                    const codePointValue = (cpv = elem.codePointAt(0)) !== undefined ? cpv : 0;
                    if (codePointValue <= 255 || (codePointValue >= 0xff61 && codePointValue <= 0xff9f || eastAsianAmbiguous.includes(codePointValue)))
                        ++len;
                    else
                        // Double width
                        len += 2;
                });
                return len;
            },
        })
        .use(remarkStringify, remarksOptions)
        .use(remarkFrontmatter)
        .stringify(mdNode);

    if (srcMarkdown === dstMarkdown) {
        vscode.window.showInformationMessage('Document is already formatted.');
        return;
    }

    editor.edit((editBuilder) => {
        // Replace with formatted markdown
        const firstLine = document.lineAt(0);
        const lastLine = document.lineAt(document.lineCount - 1);
        editBuilder.replace(new vscode.Range(firstLine.range.start, lastLine.range.end), dstMarkdown);
        vscode.window.showInformationMessage('Format completed.');
    });
}