esm: improve typings and code coverage

PR-URL: https://github.com/nodejs/node/pull/42305
Reviewed-By: Geoffrey Booth <webadmin@geoffreybooth.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Mestery <mestery@protonmail.com>
Reviewed-By: Mohammed Keyvanzadeh <mohammadkeyvanzade94@gmail.com>
Reviewed-By: Jacob Smith <jacob@frende.me>
Reviewed-By: Darshan Sen <raisinten@gmail.com>

lib/internal/modules/esm/formats.js

@@ -29,6 +29,10 @@ if (experimentalWasmModules) {
   extensionFormatMap['.wasm'] = legacyExtensionFormatMap['.wasm'] = 'wasm';
 }
 
+/**
+ * @param {string} mime
+ * @returns {string | null}
+ */
 function mimeToFormat(mime) {
   if (
     RegExpPrototypeTest(

lib/internal/modules/esm/get_format.js

@@ -32,6 +32,10 @@ const protocolHandlers = ObjectAssign(ObjectCreate(null), {
   'node:'() { return 'builtin'; },
 });
 
+/**
+ * @param {URL} parsed
+ * @returns {string | null}
+ */
 function getDataProtocolModuleFormat(parsed) {
   const { 1: mime } = RegExpPrototypeExec(
     /^([^/]+\/[^;,]+)(?:[^,]*?)(;base64)?,/,
@@ -41,6 +45,12 @@ function getDataProtocolModuleFormat(parsed) {
   return mimeToFormat(mime);
 }
 
+/**
+ * @param {URL} url
+ * @param {{parentURL: string}} context
+ * @param {boolean} ignoreErrors
+ * @returns {string}
+ */
 function getFileProtocolModuleFormat(url, context, ignoreErrors) {
   const ext = extname(url.pathname);
   if (ext === '.js') {
@@ -59,6 +69,11 @@ function getFileProtocolModuleFormat(url, context, ignoreErrors) {
   return getLegacyExtensionFormat(ext) ?? null;
 }
 
+/**
+ * @param {URL} url
+ * @param {{parentURL: string}} context
+ * @returns {Promise<string> | undefined} only works when enabled
+ */
 function getHttpProtocolModuleFormat(url, context) {
   if (experimentalNetworkImports) {
     return PromisePrototypeThen(
@@ -70,6 +85,11 @@ function getHttpProtocolModuleFormat(url, context) {
   }
 }
 
+/**
+ * @param {URL | URL['href']} url
+ * @param {{parentURL: string}} context
+ * @returns {Promise<string> | string | undefined} only works when enabled
+ */
 function defaultGetFormatWithoutErrors(url, context) {
   const parsed = new URL(url);
   if (!ObjectPrototypeHasOwnProperty(protocolHandlers, parsed.protocol))
@@ -77,6 +97,11 @@ function defaultGetFormatWithoutErrors(url, context) {
   return protocolHandlers[parsed.protocol](parsed, context, true);
 }
 
+/**
+ * @param {URL | URL['href']} url
+ * @param {{parentURL: string}} context
+ * @returns {Promise<string> | string | undefined} only works when enabled
+ */
 function defaultGetFormat(url, context) {
   const parsed = new URL(url);
   return ObjectPrototypeHasOwnProperty(protocolHandlers, parsed.protocol) ?

lib/internal/modules/esm/resolve.js

@@ -79,6 +79,7 @@ const DEFAULT_CONDITIONS_SET = new SafeSet(DEFAULT_CONDITIONS);
  * @typedef {string | string[] | Record<string, unknown>} Exports
  * @typedef {'module' | 'commonjs'} PackageType
  * @typedef {{
+ *   pjsonPath: string,
  *   exports?: ExportConfig;
  *   name?: string;
  *   main?: string;

test/es-module/test-esm-basic-imports.mjs

@@ -1,7 +1,10 @@
 import '../common/index.mjs';
 import assert from 'assert';
 import ok from '../fixtures/es-modules/test-esm-ok.mjs';
-import okShebang from './test-esm-shebang.mjs';
+import * as okShebangNs from './test-esm-shebang.mjs';
+// encode the '.'
+import * as okShebangPercentNs from './test-esm-shebang%2emjs';
 
 assert(ok);
-assert(okShebang);
+assert(okShebangNs.default);
+assert.strict.equal(okShebangNs, okShebangPercentNs);