Poetry: support for poetry add --latest

[Woile]

• [x] I have searched the issues of this repo and believe that this is not a duplicate.
• [x] I have searched the documentation and believe that my question is not covered.

Feature Request

Add a way to update to latest released version. Let's say you are using gunicorn 18.x.x and you want to install the latest gunicorn 19.x.x.
Right now I couldn't find a straight forward way to do it. I found out that removing the package from the pyproject.toml and doing poetry add <package> does what I want.

Ideally I think it would be nice to have something like:
poetry add <package> --latest

Notes

Doing poetry add <package>==<latest_version> works also, but it's not the right way, because the pyproject.toml will be updated with a =<version> instead of ^<version>.

I searched a lot and couldn't find the solution, so in case it's already there I'll try to update the docs.

[uSpike]

If you have gunicorn = "^18" in your pyproject.toml and then run poetry update gunicorn, it will update to the latest gunicorn available.

[radek-sprta]

And if you always want get the latest version, just pin it to gunicorn = "*" in pyproject.yml.

[Woile]

My use case is different. I want to update once to the latest, not always install the latest, so no *, and I want to update the major, so no ^. In yarn for example you can do yarn add x@latest so it will install latest and will pin your version to the latest with a caret.

The main idea of this is that you manually update to the latest major. Otherwise you poetry update the minors

[uSpike]

If i'm understanding, you'd want

gunicorn = "18.*"

and then change it to

gunicorn = "19.*"

and run poetry update?

[Woile]

No, I would like to have:

gunicorn = "^18"

and then do

poetry add gunicorn --latest

and I would see reflected in my pyproject.toml

gunicorn = "^19"

Otherwise a user has to manually search for the latest version.

[hangtwenty]

My 2c: I think this is an impedance mismatch between the pyproject and the lockfile...

[Woile]

I don't see how, it should update the deps if possible, otherwise error. yarn and npm have this behaviour irc.

[sdispater]

Added in https://github.com/sdispater/poetry/pull/1221