When I use Collection2 in angular2-meteor project, these kinds of codes from demo always give me warning in the terminal:
No best common type exists among return expressions.
How can I improve the codes? Thanks
{
createdAt: {
type: Date,
autoValue: function() {
if (this.isInsert) {
return new Date();
} else if (this.isUpsert) {
return {$setOnInsert: new Date()};
} else {
this.unset();
}
}
}
}
Since a type of Date is expected for EVERY return branch, you must return a Date type for every if/else branch OR you can create a union that returns two different types.
In either case, you can return null for the third condition if the type is Date. That is valid in typescript.