feat(scripts): add diff:flat script

package.json

@@ -67,6 +67,7 @@
     "cli-progress": "^3.12.0",
     "compare-versions": "~6.1.0",
     "deep-diff": "~1.0.2",
+    "diff": "^7.0.0",
     "es-main": "~1.3.0",
     "eslint": "~8.57.0",
     "eslint-config-standard": "~17.1.0",
@@ -88,6 +89,7 @@
     "ora": "~8.1.0",
     "prettier": "~3.4.0",
     "sinon": "^19.0.1",
+    "strip-ansi": "^7.1.0",
     "tempy": "^3.1.0",
     "ts-node": "~10.9.1",
     "typescript": "~5.7.2",
@@ -99,6 +101,7 @@
     "save-git-history": "node --loader=ts-node/esm --no-warnings=ExperimentalWarning scripts/save-git-history.ts",
     "prepare": "(husky || true) && npm run gentypes && npm run build",
     "diff": "node --loader=ts-node/esm --no-warnings=ExperimentalWarning scripts/diff.ts",
+    "diff:flat": "node --loader=ts-node/esm --no-warnings=ExperimentalWarning scripts/diff-flat.ts",
     "unittest": "NODE_ENV=test c8 mocha index.test.ts --recursive \"{,!(node_modules)/**}/*.test.ts\"",
     "coverage": "c8 report -r lcov && open-cli coverage/lcov-report/index.html",
     "format": "eslint . && prettier --check . && tsc --noEmit",

scripts/diff-features.ts

@@ -1,26 +1,16 @@
 /* This file is a part of @mdn/browser-compat-data
  * See LICENSE file for more information. */
 
-import { exec, execSync } from 'node:child_process';
+import { execSync } from 'node:child_process';
 import fs from 'node:fs';
-import { promisify } from 'node:util';
 import path from 'node:path';
 
 import esMain from 'es-main';
 import yargs from 'yargs';
 import { hideBin } from 'yargs/helpers';
 import { temporaryDirectoryTask } from 'tempy';
 
-/**
- * Executes a command asynchronously.
- * @param command The command to execute asynchronously.
- * @returns The output of the command.
- */
-const execAsync = async (command: string): Promise<string> => {
-  const result = await promisify(exec)(command, { encoding: 'utf-8' });
-
-  return result.stdout.trim();
-};
+import { execAsync } from '../utils/index.js';
 
 /**
  * Compare two references and print diff as Markdown or JSON