From fa51418516e740d7aad839f448f51fde6f5edd43 Mon Sep 17 00:00:00 2001
From: Outsider <outsideris@gmail.com>
Date: Thu, 21 Jan 2021 03:44:32 +0900
Subject: [PATCH] show where syntax error from with ESM

Signed-off-by: Outsider <outsideris@gmail.com>
---
 lib/esm-utils.js | 36 +++++++++++++++++++++++++++++++++---
 1 file changed, 33 insertions(+), 3 deletions(-)

diff --git a/lib/esm-utils.js b/lib/esm-utils.js
index 604f883d9a..8a054e014a 100644
--- a/lib/esm-utils.js
+++ b/lib/esm-utils.js
@@ -2,10 +2,40 @@ const path = require('path');
 const url = require('url');
 
 const formattedImport = async file => {
-  if (path.isAbsolute(file)) {
-    return import(url.pathToFileURL(file));
+  try {
+    if (path.isAbsolute(file)) {
+      return await import(url.pathToFileURL(file));
+    }
+    return import(file);
+  } catch (err) {
+    if (err.name === 'SyntaxError') {
+      // This is a hack to print where syntax error is from.
+      // In dynamic import, it doesn't contain filename linenumber in errer.stack
+      // See https://github.com/nodejs/modules/issues/471
+      // FIXME: remove this hack after nodejs suppurt
+      return await new Promise((resolve, reject) => {
+        const {spawn} = require('child_process');
+
+        const proc = spawn(process.execPath, [
+          '--unhandled-rejections=throw',
+          '-e',
+          `import('${file}')`
+        ]);
+
+        let errMsg = '';
+
+        proc.stderr.on('data', data => {
+          errMsg += data;
+        });
+
+        proc.on('exit', () => {
+          const err = new Error(errMsg);
+          err.stack = errMsg;
+          reject(err);
+        });
+      });
+    }
   }
-  return import(file);
 };
 
 exports.requireOrImport = async file => {