From cb127964baca169921e53b7cc7426534a8e76dde Mon Sep 17 00:00:00 2001
From: Graham McIntire <graham@mcintire.me>
Date: Fri, 24 Apr 2026 08:23:51 -0500
Subject: [PATCH] test: RegexCache LRU eviction path (100% coverage)

---
 test/aprsme/regex_cache_test.exs | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/test/aprsme/regex_cache_test.exs b/test/aprsme/regex_cache_test.exs
index 42da87d..06e9e8d 100644
--- a/test/aprsme/regex_cache_test.exs
+++ b/test/aprsme/regex_cache_test.exs
@@ -69,5 +69,20 @@ defmodule Aprsme.RegexCacheTest do
         assert {:ok, %Regex{}} = RegexCache.get_or_compile(p)
       end
     end
+
+    test "exercises LRU eviction when cache grows past the max-size threshold" do
+      # Generate enough patterns to push past @max_cache_size (1000).
+      # Existing cache entries count too, so overshoot by ~150 to be safe.
+      patterns = for i <- 1..1_200, do: "lru_pattern_#{System.unique_integer()}_#{i}"
+
+      for p <- patterns do
+        assert {:ok, %Regex{}} = RegexCache.get_or_compile(p)
+      end
+
+      # The first few patterns should likely be evicted, but still compile fine
+      # on re-request (no caching contract violation).
+      [first | _] = patterns
+      assert {:ok, %Regex{}} = RegexCache.get_or_compile(first)
+    end
   end
 end