MapBuilder dont fail in compilation time if generics does not match on constructor

[danielgomezrico]

Currently you will have a runtime exception if you try to build a map with the wrong types.

This will allow the developer to know at compile time if what he is intending to do will work or not, avoiding bugs.

[dave26199]

The idea makes sense, but we can't land it like this: it's a breaking change. Because it's a breaking change, we'll want to make all other similar improvements at the same time. That will need considerable work that I don't have time for right now--sorry.

By the way, it's like this for historical reasons, built_collection is from the Dart 1 days when types didn't give guarantees like they do now. So there was no point to having a stricter API back then.

Thanks. I do hope to fix this at some point--but no ETA I'm afraid.

[danielgomezrico]

Thanks for answering, I created the PR as a draft and empty because I wasn't sure about the change, and I was playing the unit tests to see if I was able to reproduce my runtime issue there.

I understand that this is a breaking change, and your argument, what should I do then? Can you guide me about which other places must be updated? I can add documentation about it too.

[danielgomezrico]

@dave26199 ping :)

[davidmorgan]

Still no concrete ETA on a breaking change to built_collection, but I do hope to get to it this year; there is a small pile of issues building up.

[danielgomezrico]

@davidmorgan hi, friendly reminder

[davidmorgan]

Thanks! I've just started making some breaking changes, so this is now in scope :)

But, it will take a while: there are quite a pile of tweaks like this to work through, and I want to get them all in before doing a release.

Hopefully, some time this year :)