An example of 'Diff two files' macro for VSCodeMacros extension

DiffFiles.js

// [VSCode Macros] extension
// https://marketplace.visualstudio.com/items?itemName=EXCEEDSYSTEM.vscode-macros
// License:MIT
const vscode = require('vscode');
const fs = require('fs');

module.exports.macroCommands = {
  DiffFiles: {
    no: 1,
    func: diffFiles,
  },
};

async function diffFiles() {
  // Create the last opened path if it does not exist in the global variable area
  if (!global.bahW6wau) {
    global.bahW6wau = { last_opened_uri: undefined };
  }

  // A Local function which returns a selected file
  const checkFile = (uris) => {
    if (!uris) {
      vscode.window.showInformationMessage('Cancelled');
      return;
    }
    return uris[0];
  };

  // Get last opened path from the global variable area
  let lastUri;
  if (global.bahW6wau.last_opened_uri && fs.existsSync(global.bahW6wau.last_opened_uri.fsPath)) {
    lastUri = global.bahW6wau.last_opened_uri;
  }

  // Select both left and right files with an open file dialog
  const leftFiles = await vscode.window.showOpenDialog({ canSelectFiles: true, canSelectFolders: false, canSelectMany: false, defaultUri: lastUri, title: 'Select a left file for compare' });
  const leftFile = checkFile(leftFiles);
  if (!leftFile) return;
  lastUri = leftFile;
  // Save last opened path to the global variable area
  global.bahW6wau.last_opened_uri = lastUri;
  const rightFiles = await vscode.window.showOpenDialog({ canSelectFiles: true, canSelectFolders: false, canSelectMany: false, defaultUri: lastUri, title: 'Select a right file for compare' });
  const rightFile = checkFile(rightFiles);
  if (!rightFile) return;

  // Show the file differences with the built-in command of the VSCode
  await vscode.commands.executeCommand('vscode.diff', leftFile, rightFile, `Compare(${leftFile.fsPath} ↔ ${rightFile.fsPath})`);
}