esm: minimal resolver spec and implementation refinementsmodules-lkgr

PR URL: https://github.com/nodejs/ecmascript-modules/pull/12

1 files changed, 10 insertions, 6 deletions

diff --git a/lib/internal/errors.js b/lib/internal/errors.js
index 0ed23a9438..9c7aa71bd4 100644
--- a/lib/internal/errors.js
+++ b/lib/internal/errors.js
@@ -800,11 +800,13 @@ E('ERR_MISSING_ARGS',
 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_MODULE', 'Cannot find module %s', Error);
-E('ERR_MODULE_RESOLUTION_LEGACY',
-  '%s not found by import in %s.' +
-    ' Legacy behavior in require() would have found it at %s',
-  Error);
+E('ERR_MODULE_NOT_FOUND', (module, base, legacyResolution) => {
+  let msg = `Cannot find module '${module}' imported from ${base}.`;
+  if (legacyResolution)
+    msg += ' Legacy behavior in require() would have found it at ' +
+           legacyResolution;
+  return msg;
+}, Error);
 E('ERR_MULTIPLE_CALLBACK', 'Callback called multiple times', Error);
 E('ERR_NAPI_CONS_FUNCTION', 'Constructor must be a function', TypeError);
 E('ERR_NAPI_INVALID_DATAVIEW_ARGS',
@@ -898,11 +900,13 @@ E('ERR_UNHANDLED_ERROR',
     if (err === undefined) return msg;
     return `${msg} (${err})`;
   }, Error);
+// This should probably be a `TypeError`.
 E('ERR_UNKNOWN_CREDENTIAL', '%s identifier does not exist: %s', Error);
 E('ERR_UNKNOWN_ENCODING', 'Unknown encoding: %s', TypeError);
 
 // This should probably be a `TypeError`.
-E('ERR_UNKNOWN_FILE_EXTENSION', 'Unknown file extension: %s', Error);
+E('ERR_UNKNOWN_FILE_EXTENSION', 'Unknown file extension: \'%s\' imported ' +
+  'from %s', Error);
 E('ERR_UNKNOWN_MODULE_FORMAT', 'Unknown module format: %s', RangeError);
 E('ERR_UNKNOWN_SIGNAL', 'Unknown signal: %s', TypeError);
 E('ERR_UNKNOWN_STDIN_TYPE', 'Unknown stdin file type', Error);