I have a TODOs list, (Todo[ ]) and I want to sort it every time I make
You need to change your html template so that your pipe can accommodate your async code.
Change this line:
(...)
To this:
I copied your Pipe code into this Plunker:
https://plnkr.co/edit/RBpZilgxIyRDLwktNZN1?p=preview