Interpolate variable in multiline vanilla javascipt - string

Question

Recently, I wanted to develop a plugin for javascipt for visual studio code. It's essence is to generate 3 files with template text in them. I stored the template text as a multiline string in a variable, but I never managed to insert the variable interpolation into the multiline string.
Code sample below:
const blocName = await vscode.window.showInputBox({
placeHolder: "Bloc name",
prompt: "Enter the BLoC name",
});
const blocNameLower = blocName.toLowerCase();
const bloc = 'import \'dart:async\';\n\
import \'package:${blocNameLower}_bloc/bloc.dart\'\;\n\
import \'package:meta/meta.dart\';\n\
\n\
part \'${blocNameLower}_event.dart\';\n\
part \'${blocNameLower}_state.dart\';\n\
\n\
class ${blockName}Bloc extends Bloc<${blockName}Event, ${blockName}State> {\n\
${blockName}Bloc() : super(${blockName}Initial()) {\n\
on<${blockName}Event>((event, emit) {\n\
// TODO: implement event handler\n\
});\n\
}\n\
}';
Let's assume input is Test:
Actual behavior:
import 'dart:async';
import 'package:${blocNameLower}_bloc/bloc.dart';
import 'package:meta/meta.dart';
part '**${blocNameLower}**_event.dart';
part '${blocNameLower}_state.dart';
class ${blockName}Bloc extends Bloc<${blockName}Event, ${blockName}State> {
${blockName}Bloc() : super(${blockName}Initial()) {
on<${blockName}Event>((event, emit) {
// TODO: implement event handler
});
}
}
Expected behavior:
import 'dart:async';
import 'package:test_bloc/bloc.dart';
import 'package:meta/meta.dart';
part '**test**_event.dart';
part 'test_state.dart';
class TestBloc extends Bloc<TestEvent, TestState> {
TestBloc() : super(TestInitial()) {
on<TestEvent>((event, emit) {
// TODO: implement event handler
});
}
}
Is there any chance to interpolate variable in multiline line..(as with 'part test_event.dart';) ?