Add tests for cacheMethodFilter

lib/Cake/Model/Datasource/DboSource.php

@@ -797,6 +797,37 @@ public function cacheMethod($method, $key, $value = null) {
  * Filters to apply to the results of `name` and `fields`. When the filter for a given method does not return `true`
  * then the result is not added to the memory cache.
  *
+ * Some examples:
+ *
+ * ```
+ * // For method fields, do not cache values that contain floats
+ * if ($method === 'fields') {
+ * 	$hasFloat = preg_grep('/(\d+)?\.\d+/', $value);
+ *
+ * 	return count($hasFloat) === 0;
+ * }
+ *
+ * return true;
+ * ```
+ *
+ * ```
+ * // For method name, do not cache values that have the name created
+ * if ($method === 'name') {
+ * 	return preg_match('/^`created`$/', $value) !== 1;
+ * }
+ *
+ * return true;
+ * ```
+ *
+ * ```
+ * // For method name, do not cache values that have the key 472551d38e1f8bbc78d7dfd28106166f
+ * if ($key === '472551d38e1f8bbc78d7dfd28106166f') {
+ * 	return false;
+ * }
+ *
+ * return true;
+ * ```
+ *
  * @param string $method Name of the method being cached.
  * @param string $key The key name for the cache operation.
  * @param mixed $value The value to cache into memory.

lib/Cake/Test/Case/Model/Datasource/DboSourceTest.php

@@ -737,6 +737,34 @@ public function testCacheMethod() {
 		$this->assertNull($result);
 	}
 
+/**
+ * Test that cacheMethodFilter does not filter by default.
+ *
+ * @return void
+ */
+	public function testCacheMethodFilter() {
+		$method = 'name';
+		$key = '49d9207adfce6df1dd3ee8c30c434414';
+		$value = '`menus`';
+		$actual = $this->testDb->cacheMethodFilter($method, $key, $value);
+
+		$this->assertTrue($actual);
+
+		$method = 'fields';
+		$key = '2b57253ab1fffb3e95fa4f95299220b1';
+		$value = ["`Menu`.`id`", "`Menu`.`name`"];
+		$actual = $this->testDb->cacheMethodFilter($method, $key, $value);
+
+		$this->assertTrue($actual);
+
+		$method = 'non-existing';
+		$key = '';
+		$value = '``';
+		$actual = $this->testDb->cacheMethodFilter($method, $key, $value);
+
+		$this->assertTrue($actual);
+	}
+
 /**
  * Test that rare collisions do not happen with method caching
  *