SDK auto-update

[DartBot]

This issue was originally filed by [email protected]

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As depot_tools and Chromium, it would be great if the SDK would check for updates when a tool is run (analyzer, dart2js, pub, dart), and either silently patch itself or offer to patch itself.

[sethladd]

Removed Type-Defect, Area-Build labels.
Added Type-Enhancement, Area-SDK, Triaged labels.

[DartBot]

This comment was originally written by @austincummings

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Is this currently being implemented by someone on the dev team? I have been working on this and may have a patch ready within the next few days. I do have a couple of questions about how to incorporate my implementation into the sdk. If a developer could email me that'd be awesome.

[pq]

My plate's too full to volunteer to shepherd this but since I'm managing the editor and plugin update story, I'm keen to see where this conversation goes...

[DartBot]

This comment was originally written by @austincummings

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Right now I have gotten a lot of the basic functionality going, with the exception of extracting using unzip and architecture detection. Now I need to find somewhere to implement my code. Originally I was going to use the wrapper scripts to run my Dart file. But now I've started thinking I should add it in as another pub command, like 'pub update-sdk' or something similar, then use the wrapper scripts to call the pub command. Pub already has a lot of the code for downloading and extracting compressed files on all OS's. So this may make it seem more like it's built into the sdk rather than just a script stowed in some directory. Or maybe I should just put it somewhere entirely different that I haven't thought of yet. What do you guys think?

[DartBot]

This comment was originally written by @seaneagan

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For reference, here's the nodeJS equivalent of this:

https://github.com/creationix/nvm

Also, it might be nice to drive such a tool using the SDK constraint in pubspec.yaml, and validate/install/use an appropriate SDK based on that.