From 357f56c8aa9e6a27f7f199ba4d627b90414ae1c1 Mon Sep 17 00:00:00 2001
From: Daniel Bayley <daniel.bayley@me.com>
Date: Thu, 15 Oct 2020 16:15:04 +0100
Subject: [PATCH] Fix retrieveSourceMapURL to prevent false matches in
 CoffeeScript codebase

This bug was hard to track down! It breaks all my tests, and has been a real hinderance to my _[jest-preset-coffeescript](https://github.com/danielbayley/jest-preset-coffeescript/runs/1254200867?check_suite_focus=true)_ package. Fixes #254.
---
 source-map-support.js | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/source-map-support.js b/source-map-support.js
index 4459386..a0c49de 100644
--- a/source-map-support.js
+++ b/source-map-support.js
@@ -147,6 +147,8 @@ function retrieveSourceMapURL(source) {
 
   // Get the URL of the source map
   fileData = retrieveFile(source);
+  // Skip sourceMappingURL in coffeescript.js, meant for emitting source maps.
+  if (source.endsWith('node_modules/coffeescript/lib/coffeescript/coffeescript.js')) return null
   var re = /(?:\/\/[@#][\s]*sourceMappingURL=([^\s'"]+)[\s]*$)|(?:\/\*[@#][\s]*sourceMappingURL=([^\s*'"]+)[\s]*(?:\*\/)[\s]*$)/mg;
   // Keep executing the search to find the *last* sourceMappingURL to avoid
   // picking up sourceMappingURLs from comments, strings, etc.