IHF: More tests added.

Author: dmitry-ivanov

tests/StrLowerTest.php

@@ -14,6 +14,12 @@ public function it_works_with_lowercased_string()
         $this->assertEquals('test', str_lower('test'));
     }
 
+    /** @test */
+    public function it_works_with_lowercased_sentence()
+    {
+        $this->assertEquals('another test', str_lower('another test'));
+    }
+
     /** @test */
     public function it_lowers_capitalized_word()
     {

tests/StrUpperTest.php

@@ -14,6 +14,12 @@ public function it_works_with_uppercased_string()
         $this->assertEquals('TEST', str_upper('TEST'));
     }
 
+    /** @test */
+    public function it_works_with_uppercased_sentence()
+    {
+        $this->assertEquals('ANOTHER TEST', str_upper('ANOTHER TEST'));
+    }
+
     /** @test */
     public function it_uppers_capitalized_word()
     {