Tests_Formatting_ConvertInvalidEntities: add extra test cases

... to actually test the method properly.

Author: jrfnl

tests/phpunit/tests/formatting/ConvertInvalidEntries.php

@@ -24,15 +24,31 @@ public function test_convert_invalid_entities( $input, $expected ) {
 	 */
 	public function data_convert_invalid_entities_strings() {
 		return array(
+			'empty string'                                => array(
+				'input'    => '',
+				'expected' => '',
+			),
 			'replaces windows1252 entities with unicode ones' => array(
 				'input'    => '‚ƒ„…†‡ˆ‰Š‹Œ‘’“”•–—˜™š›œŸ',
 				'expected' => '‚ƒ„…†‡ˆ‰Š‹Œ‘’“”•–—˜™š›œŸ',
 			),
 			// @ticket 20503
-			'replaces latin letter z with caron' => array(
+			'replaces latin letter z with caron'          => array(
 				'input'    => 'Žž',
 				'expected' => 'Žž',
 			),
+			'string without entity is returned unchanged' => array(
+				'input'    => 'Hello! This is just text.',
+				'expected' => 'Hello! This is just text.',
+			),
+			'string with unlisted entity is returned unchanged' => array(
+				'input'    => 'English pound: £.',
+				'expected' => 'English pound: £.',
+			),
+			'string with entity in thousand range (not win 1252) is returned unchanged' => array(
+				'input'    => 'Їԣ',
+				'expected' => 'Їԣ',
+			),
 		);
 	}