Use ESM in Node.js code generation scripts (#2739)

scripts/style-code.mjs

@@ -0,0 +1,97 @@
+// EJS Helpers
+
+import ejs from "ejs";
+import fs from "node:fs";
+
+import path from "node:path";
+
+/**
+ * @param {() => boolean} condition
+ * @param {string} val
+ * @returns {string}
+ */
+export function iff(condition, val) {
+  return condition() ? val : "";
+};
+
+/**
+ * @param {string} str 
+ * @returns {string}
+ */
+export function camelize(str) {
+  return str.replace(/(?:^|-)(.)/g, function (_, x) {
+    return x.toUpperCase();
+  });
+};
+
+/**
+ * @param {string} str 
+ * @returns {string}
+ */
+export function camelizeWithLeadingLowercase(str) {
+  return str.replace(/-(.)/g, function (_, x) {
+    return x.toUpperCase();
+  });
+};
+
+export function snakeCaseUpper(/** @type {string} **/ str) {
+  return str.replace(/-/g, "_").toUpperCase();
+};
+
+export function unhyphenate (/** @type {string} **/ str) {
+ return str.replace(/-/g, " ");
+};
+
+// Write out a list of files that this script is modifying so that we can check
+/** @type {string[]} **/
+let files = [];
+process.on('exit', function() {
+  const list = path.join(path.dirname(process.argv[1]), path.basename(process.argv[1], '.js') + '.list');
+  console.log(`Writing files that this script modifies to: ${list}`);
+  fs.writeFileSync(list, files.join("\n"));
+});
+
+/**
+ * 
+ * @param {string} filename 
+ * @param {string} newContent 
+ * @param {string} output 
+ */
+export function writeIfModified(filename, newContent, output) {
+  if (output) {
+    filename = path.resolve(path.join(output, filename));
+  }
+
+  const info = path.parse(filename);
+  if (!fs.existsSync(info.dir)) {
+    fs.mkdirSync(info.dir, {recursive: true});
+  }
+
+  files.push(filename);
+  try {
+    const oldContent = fs.readFileSync(filename, 'utf8');
+    if (oldContent == newContent) {
+      console.warn(`* Skipping file '${filename}' because it is up-to-date`);
+      return;
+    }
+  } catch(err) {
+  }
+  if (['0', 'false'].indexOf(process.env.DRY_RUN || '0') !== -1) {
+    fs.writeFileSync(filename, newContent);
+  }
+  console.warn(`* Updating outdated file '${filename}'`);
+};
+
+/**
+ * 
+ * @param {string} filename 
+ * @param {string} root 
+ * @returns 
+ */
+export function readAndCompile(filename, root) {
+  if (root) {
+    filename = path.resolve(path.join(root, filename));
+  }
+
+  return ejs.compile(fs.readFileSync(filename, 'utf8'), {strict: true});
+}