test: RegexCache LRU eviction path (100% coverage)

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