Add unit test for callback generated data tables

tests/Whoops/Handler/PrettyPageHandlerTest.php

@@ -119,6 +119,60 @@ class PrettyPageHandlerTest extends TestCase
         $this->assertEmpty($handler->getDataTables('ZIMBABWE!'));
     }
 
+    /**
+     * @covers Whoops\Handler\PrettyPageHandler::getDataTables
+     * @covers Whoops\Handler\PrettyPageHandler::addDataTableCallback
+     */
+    public function testSetCallbackDataTables()
+    {
+        $handler = $this->getHandler();
+
+        $this->assertEmpty($handler->getDataTables());
+        $table1 = function() {
+            return array(
+                'hammer' => 'time',
+                'foo'    => 'bar',
+            );
+        };
+        $expected1 = array('hammer' => 'time', 'foo' => 'bar');
+
+        $table2 = function() use ($expected1) {
+            return array(
+                'another' => 'table',
+                'this'    => $expected1,
+            );
+        };
+        $expected2 = array('another' => 'table', 'this' => $expected1);
+
+        $table3 = create_function('', 'return array("oh my" => "how times have changed!");');
+        $expected3 = array('oh my' => 'how times have changed!');
+
+        // Sanity check, make sure expected values really are correct.
+        $this->assertSame($expected1, $table1());
+        $this->assertSame($expected2, $table2());
+        $this->assertSame($expected3, $table3());
+
+        $handler->addDataTableCallback('table1', $table1);
+        $handler->addDataTableCallback('table2', $table2);
+        $handler->addDataTableCallback('table3', $table3);
+
+        $tables = $handler->getDataTables();
+        $this->assertCount(3, $tables);
+
+        // Supplied callable is wrapped in a closure
+        $this->assertInstanceOf('Closure', $tables['table1']);
+        $this->assertInstanceOf('Closure', $tables['table2']);
+        $this->assertInstanceOf('Closure', $tables['table3']);
+
+        // Run each wrapped callable and check results against expected output.
+        $this->assertEquals($expected1, $tables['table1']());
+        $this->assertEquals($expected2, $tables['table2']());
+        $this->assertEquals($expected3, $tables['table3']());
+
+        $this->assertSame($tables['table1'], $handler->getDataTables('table1'));
+        $this->assertSame($expected1, call_user_func($handler->getDataTables('table1')));
+    }
+
     /**
      * @covers Whoops\Handler\PrettyPageHandler::setEditor
      * @covers Whoops\Handler\PrettyPageHandler::getEditorHref