René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"vm.Module.evaluate() morphs loader errors into module evaluation rejections","articleBody":"This came up in https://github.com/nodejs/node/pull/60205#discussion_r2423587581 when I was trying to make `vm.Module.evaluate()` return the module evaluation promise as-is (so synchronously fulfilled for synthetic modules and source text modules without TLA). Currently the validation errors, `ERR_VM_MODULE_STATUS`, `THROW_ERR_SCRIPT_EXECUTION_TIMEOUT`, and `THROW_ERR_SCRIPT_EXECUTION_INTERRUPTED` would always be rejected, so for a synchronous loader, they would either have to expose these underlying rejections to users when the loading goes wrong, or be forced to become asynchronous as it cannot catch these errors synchronously and paint it over. i.e. they cannot do something like this:\n\n```js\nfunction syncLoad() {\n  try {\n    mod.evaluate();\n  } catch(e) {  // This allows the user to get the loader errors synchronously\n    if (e.code === 'ERR_VM_MODULE_STATUS' ||\n        e.code === 'ERR_SCRIPT_EXECUTION_INTERRUPTED' ||\n        e.code === 'ERR_SCRIPT_EXECUTION_TIMEOUT') {\n      // fix it up and try again, or error and explain to user what to do\n      // but hide the errors that do not directly come from module code\n      // as implementation detail\n    }\n  }\n  if (mod.status === 'errored') {\n    throw mod.error;  // It's an evaluation error from the module code\n  }\n  return mod.namespace;\n}\n```\n\nOpening a separate issue to discuss if there's another way to make this possible other than just making it throw these loader errors synchronously.","author":{"url":"https://github.com/joyeecheung","@type":"Person","name":"joyeecheung"},"datePublished":"2025-10-13T10:39:51.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":5},"url":"https://github.com/60242/node/issues/60242"}