From 91b84d680ccfeef902c68fc68fbeb11a9119892e Mon Sep 17 00:00:00 2001
From: Chengzhong Wu <cwu631@bloomberg.net>
Date: Wed, 25 Feb 2026 15:06:44 -0500
Subject: [PATCH] lib: fix source map url parse in dynamic imports

---
 lib/internal/source_map/source_map_cache.js  |  7 +++--
 test/parallel/test-source-map-invalid-url.js | 33 ++++++++++++++++++++
 2 files changed, 38 insertions(+), 2 deletions(-)
 create mode 100644 test/parallel/test-source-map-invalid-url.js

diff --git a/lib/internal/source_map/source_map_cache.js b/lib/internal/source_map/source_map_cache.js
index a4a95ad0ae49c3..95b09090c4739c 100644
--- a/lib/internal/source_map/source_map_cache.js
+++ b/lib/internal/source_map/source_map_cache.js
@@ -247,7 +247,10 @@ function dataFromUrl(sourceURL, sourceMappingURL) {
     }
   }
 
-  const mapURL = new URL(sourceMappingURL, sourceURL).href;
+  const mapURL = URLParse(sourceMappingURL, sourceURL);
+  if (mapURL === null) {
+    return null;
+  }
   return sourceMapFromFile(mapURL);
 }
 
@@ -276,7 +279,7 @@ function lineLengths(content) {
 
 /**
  * Read source map from file.
- * @param {string} mapURL - file url of the source map
+ * @param {URL} mapURL - file url of the source map
  * @returns {object} deserialized source map JSON object
  */
 function sourceMapFromFile(mapURL) {
diff --git a/test/parallel/test-source-map-invalid-url.js b/test/parallel/test-source-map-invalid-url.js
new file mode 100644
index 00000000000000..4da4ff78993cfa
--- /dev/null
+++ b/test/parallel/test-source-map-invalid-url.js
@@ -0,0 +1,33 @@
+// Flags: --enable-source-maps
+'use strict';
+
+const common = require('../common');
+
+// TODO(legendecas): c8 will complain if non-file-scheme is used in source maps.
+// https://github.com/bcoe/c8/blob/ee2f1cfc5584d41bb2d51b788d0953dab0c798f8/lib/report.js#L517
+const sources = [
+  `
+  //# sourceMappingURL=file://invalid:/file/url
+  //# sourceURL=file://invalid:/file/url
+  `,
+  `
+  //# sourceMappingURL=invalid-url
+  //# sourceURL=invalid-url
+  `,
+];
+
+sources.forEach(test);
+
+function test(source) {
+  // Eval should tolerate invalid source map url
+  eval(source);
+
+  const base64 = Buffer.from(source).toString('base64url');
+
+  // Dynamic import should tolerate invalid source map url
+  import(`data:text/javascript;base64,${base64}`)
+    .then(common.mustCall());
+}
+
+// eslint-disable-next-line @stylistic/js/spaced-comment
+//# sourceMappingURL=invalid-url