add regression test for nullable parameter types

Author: patinthehat

tests/SearcherTest.php

@@ -289,4 +289,14 @@ public function it_can_handle_chained_static_and_regular_calls()
 
         $this->assertMatchesSnapshot($results->results);
     }
+
+    /** @test */
+    public function it_can_handle_nullable_parameters()
+    {
+        $results = $this->getSearcher()
+            ->functions(['testFive'])
+            ->search(tests_path('data/file5.php'));
+
+        $this->assertMatchesSnapshot($results->results);
+    }
 }

tests/__snapshots__/SearcherTest__it_can_handle_nullable_parameters__1.yml

@@ -0,0 +1,4 @@
+-
+    location: { column: 0, endLine: 6, startLine: 3 }
+    node: { args: [{ type: Param, default: null, location: { column: 0, endLine: 3, startLine: 3 }, name: one }], name: testFive, location: { column: 0, endLine: 6, startLine: 3 } }
+    snippet: null

tests/data/file5.php

@@ -0,0 +1,6 @@
+<?php
+
+function testFive(?string $one)
+{
+    return 'one';
+}