Ticket #43583: 43583.2.patch

src/wp-includes/compat.php

@@ -505 +505 @@
 if ( ! function_exists( 'spl_autoload_register' ) ) {
         require_once ABSPATH . WPINC . '/spl-autoload-compat.php';
 }
+
+if ( ! function_exists( 'is_countable' ) ) {
+        /**
+         * Polyfill for is_countable function added in PHP 7.3.
+         *
+         * Verify that the content of a variable is an array or an object
+         * implementing Countable
+         *
+         * @since 4.9.6
+         *
+         * @param mixed $var The value to check.
+         *
+         * @return bool Returns true if var is countable, false otherwise.
+         */
+        function is_countable( $var ) {
+                return ( is_array( $var ) || $var instanceof Countable );
+        }
+}

tests/phpunit/tests/compat.php

@@ -186 +186 @@
                 $this->assertEquals( '["foo"]', $json->encodeUnsafe( array( 'foo' ) ) );
                 $this->assertEquals( array( 'foo' ), $json->decode( '["foo"]' ) );
         }
+
+        /**
+         * @ticket 43583
+         */
+        function test_is_countable_availability() {
+                $this->assertTrue( function_exists( 'is_countable' ) );
+        }
+
+        /**
+         * Test is_countable polyfill.
+         *
+         * @ticket 43583
+         *
+         * @dataProvider countable_variable_test_data
+         */
+        function test_is_countable_functionality($variable, $is_countable) {
+                $this->assertEquals( is_countable( $variable ), $is_countable );
+        }
+
+        /**
+         * Data provider for test_is_countable_functionality test. First array value
+         * is the variable, and the second value is the expected return value of the
+         * PHP 7.3's is_countable function.
+         *
+         * @ticket 43583
+         *
+         * @return array test data.
+         */
+        public function countable_variable_test_data() {
+                return array(
+                        array( true, false ),
+                        array( new stdClass(), false ),
+                        array( new ArrayIteratorFake(), true ),
+                        array( new CountableFake(), true ),
+                        array( 16, false ),
+                        array( null, false ),
+                        array( array( 1, 2, 3 ), true ),
+                        array( (array) 1, true ),
+                        array( (object) array( 'foo', 'bar', 'baz' ), false ),
+                );
+        }
 }
 
 /* used in test_mb_substr_phpcore */
@@ -194 +235 @@
                 return 'Class A object';
         }
 }
+
+class ArrayIteratorFake extends ArrayIterator {
+}
+
+class CountableFake implements Countable {
+        public function count() {
+                return 16;
+        }
+}