Instances can be double instantiated when you use multiple assemblers

[FrancisBourre]

will complete later...

[aismagulov]

Actually, this happens with one assembler.
If we have context1.xml and context2.xml, that depends on it, then after that:

public static function assembleContext1(): Void
{
    XmlCompiler.readXmlFileWithAssembler(_applicationAssembler, context1.xml");
}

public static function assembleContext2(): Void
{
    XmlCompiler.readXmlFileWithAssembler(_applicationAssembler, context2.xml");
}

in compiled JS code I see instantiating and registering objects from context1 both in assembleContext1 and assembleContext2 methods.

[aismagulov]

It looks like it happens even if objects are not related in DSL.
For example there is an object in context1.xml, that is not mentioned in context2.xml at all:

<module id="initialLayoutModule" type="foo.bar.InitialLayoutModule" map-type="foo.bar.IInitialLayoutModule">
    <argument ref="initialLayoutView"/>
</module>

Nevertheless, in compliled code I get this code both in assembleContext1 and assembleContext2 methods:

var initialLayoutModule = new foo_bar_InitialLayoutModule(initialLayoutView);
__applicationContextInjector.mapToValue(foo_bar_IInitialLayoutModule,initialLayoutModule,"initialLayoutModule");
coreFactory.register("initialLayoutModule",initialLayoutModule);

And since both XMLs are in the same context, the coreFactory is the same in both cases, therefore there is an error of duplicate registering.