The expression return new yii\db\Expres....$ids_sql.')', $params) returns the type yii\db\Expression which is incompatible with the return type mandated by hiqdev\yii\DataMapper\qu...rface::buildCondition() of array|yii\db\conditions\ConditionInterface.
In the issue above, the returned value is violating the contract defined by the
mentioned interface.
Let's take a look at an example:
interfaceHasName{/** @return string */publicfunctiongetName();}className{public$name;}classUserimplementsHasName{/** @return string|Name */publicfunctiongetName(){returnnewName('foo');// This is a violation of the ``HasName`` interface// which only allows a string value to be returned.}}
In the issue above, the returned value is violating the contract defined by the mentioned interface.
Let's take a look at an example: