Update lib/internal/modules/helpers.js

Co-authored-by: Antoine du Hamel <[email protected]>

Author: marco-ippolito

lib/internal/modules/helpers.js

@@ -314,44 +314,37 @@ function getBuiltinModule(id) {
   return normalizedId ? require(normalizedId) : undefined;
 }
 
-/**
- * TypeScript parsing function, by default Amaro.transformSync.
- *  @type {Function}
- */
-let typeScriptParser;
 /**
  * The TypeScript parsing mode, either 'strip-only' or 'transform'.
  * @type {string}
  */
-let typeScriptParsingMode;
-/**
- * Whether source maps are enabled for TypeScript parsing.
- * @type {boolean}
- */
-let sourceMapEnabled;
+const getTypeScriptParsingMode = getLazy(() =>
+  (getOptionValue('--experimental-transform-types') ? 'transform' : 'strip-only'),
+);
 
 /**
  * Load the TypeScript parser.
- * @param {Function} parser - A function that takes a string of TypeScript code
  * and returns an object with a `code` property.
  * @returns {Function} The TypeScript parser function.
  */
-function loadTypeScriptParser(parser) {
-  if (typeScriptParser) {
-    return typeScriptParser;
-  }
+const loadTypeScriptParser = getLazy(() => {
+  const amaro = require('internal/deps/amaro/dist/index');
+  return amaro.transformSync;
+});
 
-  if (parser) {
-    typeScriptParser = parser;
-  } else {
-    const amaro = require('internal/deps/amaro/dist/index');
-    // Default option for Amaro is to perform Type Stripping only.
-    typeScriptParsingMode = getOptionValue('--experimental-transform-types') ? 'transform' : 'strip-only';
-    sourceMapEnabled = getOptionValue('--enable-source-maps');
-    // Curry the transformSync function with the default options.
-    typeScriptParser = amaro.transformSync;
+/**
+ *
+ * @param {string} source the source code
+ * @param {object} options the options to pass to the parser
+ * @returns {TransformOutput} an object with a `code` property.
+ */
+function parseTypeScript(source, options) {
+  const parse = loadTypeScriptParser();
+  try {
+    return parse(source, options);
+  } catch (error) {
+    throw new ERR_INVALID_TYPESCRIPT_SYNTAX(error);
   }
-  return typeScriptParser;
 }
 
 /**
@@ -366,14 +359,13 @@ function loadTypeScriptParser(parser) {
  */
 function stripTypeScriptTypes(source, filename) {
   assert(typeof source === 'string');
-  const parse = loadTypeScriptParser();
   const options = {
     __proto__: null,
-    mode: typeScriptParsingMode,
-    sourceMap: sourceMapEnabled,
+    mode: getTypeScriptParsingMode(),
+    sourceMap: getOptionValue('--enable-source-maps'),
     filename,
   };
-  const { code, map } = tryParse(() => parse(source, options));
+  const { code, map } = parseTypeScript(source, options);
   if (map) {
     // TODO(@marco-ippolito) When Buffer.transcode supports utf8 to
     // base64 transformation, we should change this line.
@@ -386,14 +378,6 @@ function stripTypeScriptTypes(source, filename) {
   return `${code}\n\n//# sourceURL=${filename}`;
 }
 
-function tryParse(parse) {
-  try {
-    return parse();
-  } catch (error) {
-    throw new ERR_INVALID_TYPESCRIPT_SYNTAX(error);
-  }
-}
-
 /** @type {import('internal/util/types')} */
 let _TYPES = null;
 /**