From e30161ac3cb2a67b300572e2dc1a18141631d3cb Mon Sep 17 00:00:00 2001
From: cyqsimon <28627918+cyqsimon@users.noreply.github.com>
Date: Mon, 6 Nov 2023 11:18:20 +0800
Subject: [PATCH] Add test: `builtin_mappings_matcher_only_compile_once`

---
 src/syntax_mapping.rs | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/src/syntax_mapping.rs b/src/syntax_mapping.rs
index a7923a5c..e523f85e 100644
--- a/src/syntax_mapping.rs
+++ b/src/syntax_mapping.rs
@@ -148,6 +148,23 @@ mod tests {
         let _mappings = map.builtin_mappings().collect::<Vec<_>>();
     }
 
+    #[test]
+    fn builtin_mappings_matcher_only_compile_once() {
+        let map = SyntaxMapping::new();
+
+        let two_iterations: Vec<_> = (0..2)
+            .map(|_| {
+                // addresses of every matcher
+                map.builtin_mappings()
+                    .map(|(matcher, _)| matcher as *const _ as usize)
+                    .collect::<Vec<_>>()
+            })
+            .collect();
+
+        // if the matchers are only compiled once, their address should remain the same
+        assert_eq!(two_iterations[0], two_iterations[1]);
+    }
+
     #[test]
     fn custom_mappings_work() {
         let mut map = SyntaxMapping::new();