diff --git a/tests/HelpersTest.php b/tests/HelpersTest.php
index 09c8669..c26865e 100644
--- a/tests/HelpersTest.php
+++ b/tests/HelpersTest.php
@@ -65,4 +65,68 @@ final class HelpersTest extends TestCase
 
         self::assertSame('tyumen', Helpers::current_town());
     }
+
+    public function test_current_town_returns_null_when_uri_does_not_match_and_no_filter(): void
+    {
+        $_SERVER['REQUEST_URI'] = '/some-random-page/';
+
+        \Brain\Monkey\Functions\expect('get_terms')
+            ->andReturn([10 => 'spb', 11 => 'tyumen']);
+
+        self::assertNull(Helpers::current_town());
+    }
+
+    public function test_current_town_uses_main_town_slug_filter_when_uri_has_no_match(): void
+    {
+        $_SERVER['REQUEST_URI'] = '/';
+
+        \Brain\Monkey\Functions\expect('get_terms')
+            ->andReturn([10 => 'spb', 11 => 'tyumen']);
+        \Brain\Monkey\Filters\expectApplied('wpmc_main_town_slug')
+            ->once()
+            ->with(null)
+            ->andReturn('spb');
+
+        self::assertSame('spb', Helpers::current_town());
+    }
+
+    public function test_current_town_uri_match_wins_over_main_town_filter(): void
+    {
+        $_SERVER['REQUEST_URI'] = '/tyumen/';
+
+        \Brain\Monkey\Functions\expect('get_terms')
+            ->andReturn([10 => 'spb', 11 => 'tyumen']);
+        // main_town filter should not be consulted when URI matches.
+        \Brain\Monkey\Filters\expectApplied('wpmc_main_town_slug')->never();
+
+        self::assertSame('tyumen', Helpers::current_town());
+    }
+
+    public function test_current_town_slug_filter_overrides_final_value(): void
+    {
+        $_SERVER['REQUEST_URI'] = '/';
+
+        \Brain\Monkey\Functions\expect('get_terms')
+            ->andReturn([]);
+        \Brain\Monkey\Filters\expectApplied('wpmc_current_town_slug')
+            ->once()
+            ->andReturn('override-slug');
+
+        self::assertSame('override-slug', Helpers::current_town());
+    }
+
+    public function test_current_town_memoizes_within_request(): void
+    {
+        $_SERVER['REQUEST_URI'] = '/tyumen/';
+
+        \Brain\Monkey\Functions\expect('get_terms')
+            ->once()
+            ->andReturn([10 => 'spb', 11 => 'tyumen']);
+
+        Helpers::current_town();
+        Helpers::current_town();
+        Helpers::current_town();
+
+        self::assertTrue(true);
+    }
 }