esm: port loader code to JS

lib/internal/errors.js

@@ -1078,29 +1078,50 @@ E('ERR_INVALID_FILE_URL_PATH', 'File URL path %s', TypeError);
 E('ERR_INVALID_HANDLE_TYPE', 'This handle type cannot be sent', TypeError);
 E('ERR_INVALID_HTTP_TOKEN', '%s must be a valid HTTP token ["%s"]', TypeError);
 E('ERR_INVALID_IP_ADDRESS', 'Invalid IP address: %s', TypeError);
-E('ERR_INVALID_MODULE_SPECIFIER', (pkgPath, subpath) => {
-  assert(subpath !== '.');
-  return `Package subpath '${subpath}' is not a valid module request for the ` +
-      `"exports" resolution of ${pkgPath}${sep}package.json`;
+E('ERR_INVALID_MODULE_SPECIFIER', (pkgPath, subpath, base = undefined) => {
+  if (subpath === undefined) {
+    return `Invalid package name '${pkgPath}' imported from ${base}`;
+  } else if (base === undefined) {
+    assert(subpath !== '.');
+    return `Package subpath '${subpath}' is not a valid module request for ` +
+      `the "exports" resolution of ${pkgPath}${sep}package.json`;
+  } else {
+    return `Package subpath '${subpath}' is not a valid module request for ` +
+      `the "exports" resolution of ${pkgPath} imported from ${base}`;
+  }
 }, TypeError);
 E('ERR_INVALID_OPT_VALUE', (name, value) =>
   `The value "${String(value)}" is invalid for option "${name}"`,
   TypeError,
   RangeError);
 E('ERR_INVALID_OPT_VALUE_ENCODING',
   'The value "%s" is invalid for option "encoding"', TypeError);
-E('ERR_INVALID_PACKAGE_CONFIG',
-  `Invalid package config %s${sep}package.json, %s`, Error);
-E('ERR_INVALID_PACKAGE_TARGET', (pkgPath, key, subpath, target) => {
-  if (key === '.') {
-    return `Invalid "exports" main target ${JSONStringify(target)} defined ` +
+E('ERR_INVALID_PACKAGE_CONFIG', (path, message, hasMessage = true) => {
+  if (hasMessage)
+    return `Invalid package config ${path}${sep}package.json, ${message}`;
+  else
+    return `Invalid JSON in ${path} imported from ${message}`;
+}, Error);
+E('ERR_INVALID_PACKAGE_TARGET',
+  (pkgPath, key, subpath, target, base = undefined) => {
+    if (key === null) {
+      if (subpath !== '') {
+        return `Invalid "exports" target ${JSONStringify(target)} defined ` +
+        `for '${subpath}' in the package config ${pkgPath} imported from ` +
+        base;
+      } else {
+        return `Invalid "exports" main target ${target} defined in the ` +
+          `package config ${pkgPath} imported from ${base}.`;
+      }
+    } else if (key === '.') {
+      return `Invalid "exports" main target ${JSONStringify(target)} defined ` +
       `in the package config ${pkgPath}${sep}package.json`;
-  } else {
-    return `Invalid "exports" target ${JSONStringify(target)} defined for '${
-      StringPrototypeSlice(key, 0, -subpath.length || key.length)}' in the ` +
+    } else {
+      return `Invalid "exports" target ${JSONStringify(target)} defined for '${
+        StringPrototypeSlice(key, 0, -subpath.length || key.length)}' in the ` +
       `package config ${pkgPath}${sep}package.json`;
-  }
-}, Error);
+    }
+  }, Error);
 E('ERR_INVALID_PERFORMANCE_MARK',
   'The "%s" performance mark has not been set', Error);
 E('ERR_INVALID_PROTOCOL',
@@ -1211,6 +1232,9 @@ E('ERR_MISSING_DYNAMIC_INSTANTIATE_HOOK',
   'The ES Module loader may not return a format of \'dynamic\' when no ' +
   'dynamicInstantiate function was provided', Error);
 E('ERR_MISSING_OPTION', '%s is required', TypeError);
+E('ERR_MODULE_NOT_FOUND', (path, base, type = 'package') => {
+  return `Cannot find ${type} '${path}' imported from ${base}`;
+}, Error);
 E('ERR_MULTIPLE_CALLBACK', 'Callback called multiple times', Error);
 E('ERR_NAPI_CONS_FUNCTION', 'Constructor must be a function', TypeError);
 E('ERR_NAPI_INVALID_DATAVIEW_ARGS',
@@ -1245,12 +1269,15 @@ E('ERR_OUT_OF_RANGE',
     msg += ` It must be ${range}. Received ${received}`;
     return msg;
   }, RangeError);
-E('ERR_PACKAGE_PATH_NOT_EXPORTED', (pkgPath, subpath) => {
+E('ERR_PACKAGE_PATH_NOT_EXPORTED', (pkgPath, subpath, base = undefined) => {
   if (subpath === '.') {
     return `No "exports" main resolved in ${pkgPath}${sep}package.json`;
-  } else {
+  } else if (base === undefined) {
     return `Package subpath '${subpath}' is not defined by "exports" in ${
       pkgPath}${sep}package.json`;
+  } else {
+    return `Package subpath '${subpath}' is not defined by "exports" in ${
+      pkgPath} imported from ${base}`;
   }
 }, Error);
 E('ERR_REQUIRE_ESM',

lib/internal/modules/esm/get_format.js

@@ -1,20 +1,16 @@
 'use strict';
-
+const { StringPrototypeStartsWith } = primordials;
 const { extname } = require('path');
 const { getOptionValue } = require('internal/options');
 
 const experimentalJsonModules = getOptionValue('--experimental-json-modules');
 const experimentalSpeciferResolution =
   getOptionValue('--experimental-specifier-resolution');
 const experimentalWasmModules = getOptionValue('--experimental-wasm-modules');
-const { getPackageType } = internalBinding('module_wrap');
+const { getPackageType } = require('internal/modules/esm/resolve');
 const { URL, fileURLToPath } = require('internal/url');
 const { ERR_UNKNOWN_FILE_EXTENSION } = require('internal/errors').codes;
 
-// const TYPE_NONE = 0;
-// const TYPE_COMMONJS = 1;
-const TYPE_MODULE = 2;
-
 const extensionFormatMap = {
   '__proto__': null,
   '.cjs': 'commonjs',
@@ -37,8 +33,8 @@ if (experimentalWasmModules)
 if (experimentalJsonModules)
   extensionFormatMap['.json'] = legacyExtensionFormatMap['.json'] = 'json';
 
-function defaultGetFormat(url, context, defaultGetFormat) {
-  if (url.startsWith('nodejs:')) {
+function defaultGetFormat(url, context, defaultGetFormatUnused) {
+  if (StringPrototypeStartsWith(url, 'nodejs:')) {
     return { format: 'builtin' };
   }
   const parsed = new URL(url);
@@ -55,8 +51,7 @@ function defaultGetFormat(url, context, defaultGetFormat) {
     const ext = extname(parsed.pathname);
     let format;
     if (ext === '.js') {
-      format = getPackageType(parsed.href) === TYPE_MODULE ?
-        'module' : 'commonjs';
+      format = getPackageType(parsed.href) === 'module' ? 'module' : 'commonjs';
     } else {
       format = extensionFormatMap[ext];
     }