I think it would be nice to have autocomplete and syntax check in configuration PHP arrays (Those used in config/* and for example for widgets, dataProviders and more in Yii).
Of course PHPStorm plugin it an option, but complex one, at least for PHP programmer.
This is a possible solution:
return GridView::widget([
	GridView::CONF_DataProvider => $dataProvider,
	GridView::CONF_DataColumns => [
		[
			DataColumn::CONF_Attribute => 'company_name',
			DataColumn::CONF_Format	=> 'test',
			DataColumn::CONF_Label	=> 'Company name'
		],
		[
                   'class' => 'yii\grid\ActionColumn',
                    ActionColumn::CONF_Template => '{view} {update} {delete}'
                ],
	] 
]);
Or may be there is a better option? This requires modification of framework code, so would be nice hear from maintainers, of course if there is such need I will be glad to update framework code.