From 7d457570677bea90747a6436d40db954734876df Mon Sep 17 00:00:00 2001
From: johnjbarton <johnjbarton@johnjbarton.com>
Date: Wed, 23 Dec 2020 16:32:23 -0800
Subject: [PATCH] fix(middleware): catch errors when loading a module

Fix #3572

Co-authored-by: https://github.com/jehon
---
 lib/middleware/karma.js                          |  6 +++++-
 test/e2e/error.feature                           | 16 ++++++++++++++++
 .../error/import-something-from-somewhere.js     |  2 ++
 3 files changed, 23 insertions(+), 1 deletion(-)
 create mode 100644 test/e2e/support/error/import-something-from-somewhere.js

diff --git a/lib/middleware/karma.js b/lib/middleware/karma.js
index 4e27d4a52..3a34b4e58 100644
--- a/lib/middleware/karma.js
+++ b/lib/middleware/karma.js
@@ -191,7 +191,11 @@ function createKarmaMiddleware (
             } else {
               const scriptType = (SCRIPT_TYPE[fileType] || 'text/javascript')
               const crossOriginAttribute = includeCrossOriginAttribute ? 'crossorigin="anonymous"' : ''
-              scriptTags.push(`<script type="${scriptType}" src="${filePath}" ${crossOriginAttribute}></script>`)
+              if (fileType === 'module') {
+                scriptTags.push(`<script onerror="throw 'Error loading ${filePath}'" type="${scriptType}" src="${filePath}" ${crossOriginAttribute}></script>`)
+              } else {
+                scriptTags.push(`<script type="${scriptType}" src="${filePath}" ${crossOriginAttribute}></script>`)
+              }
             }
           }
 
diff --git a/test/e2e/error.feature b/test/e2e/error.feature
index 0b327110e..09236959a 100644
--- a/test/e2e/error.feature
+++ b/test/e2e/error.feature
@@ -40,3 +40,19 @@ Feature: Error Display
       """
       SyntaxError: Unexpected token '}'
       """
+
+Scenario: Missing module Error in a test file
+    Given a configuration with:
+      """
+      files = [{pattern: 'error/import-something-from-somewhere.js', type: 'module'}];
+      browsers = ['ChromeHeadlessNoSandbox'];
+      plugins = [
+        'karma-jasmine',
+        'karma-chrome-launcher'
+      ];
+      """
+    When I start Karma
+    Then it fails with:
+      """
+      Uncaught Error loading error/import-something-from-somewhere.js
+      """
diff --git a/test/e2e/support/error/import-something-from-somewhere.js b/test/e2e/support/error/import-something-from-somewhere.js
new file mode 100644
index 000000000..1a56d4654
--- /dev/null
+++ b/test/e2e/support/error/import-something-from-somewhere.js
@@ -0,0 +1,2 @@
+import { something } from './somewhere.js'
+console.log(something)