🐛 Allow colon in zsh autocomplete values and descriptions

[snapbug]

Allow for colons in zsh completion values and descriptions, closes #162

Note that because of the startswith check escaping the completion options in the client side is not an option, as a value that includes a : for incomplete in will not pass this check.

Note that we need two levels of esacping, one for zsh, and one to preserve the escape for zsh

Tested by updating the demo.py example in the linked issue to the following:

import typer

image_desc = [
    ("alpine:latest", "latest alpine image"),
    ("alpine:hello", "fake image: for testing"),
    ("nvidia/cuda:10.0-devel-ubuntu18.04", ""),
]

def _complete(incomplete: str) -> str:
    for (image, desc) in image_desc:
        if image.startswith(incomplete):
            yield image, desc

app = typer.Typer()

@app.command()
def image(name: str = typer.Option(autocompletion=_complete)):
    typer.echo(name)

if __name__ == "__main__":
    app()

use the provided docker image/setup to test, first that the colons show as values and descriptiosn correctly

0252e3324b42# typer demo.py run --name [TAB]
alpine:hello                        -- fake image: for testing
alpine:latest                       -- latest alpine image
nvidia/cuda:10.0-devel-ubuntu18.04

and that an incomplete value with a colon generates options

0252e3324b42# typer demo.py run --name alpine:[TAB]
alpine:hello   -- fake image: for testing
alpine:latest  -- latest alpine image

[svlandeg]

Thanks for the PR! We'll review this and get back to you. Ideally, we'd love to also add a unit test for this (but that's not always easy with the autocompletion functionality)

[snapbug]

Thanks for the PR! We'll review this and get back to you. Ideally, we'd love to also add a unit test for this (but that's not always easy with the autocompletion functionality)

Agree, I took a look at the current completion tests, but they're tightly integrated into the tutorial, and couldn't think of a change for those that wasn't somewhat contrived. Open to guidance here as well.

[svlandeg]

I could confirm the bug in a zsh shell.

On master:

typer main.py run --name [TAB]
alpine       -- hello:fake image: for testing
nvidia/cuda  -- 10.0-devel-ubuntu18.04

Note that the options are wrongly split and the alpine:latest option is missing because it got collapsed into alpine:hello

With this PR:

typer main.py run --name [TAB]
alpine:hello                        -- fake image: for testing
alpine:latest                       -- latest alpine image
nvidia/cuda:10.0-devel-ubuntu18.04

Which is what you would expect.

I added tests for this use-case, the zsh ones are failing on master and succeeding on this branch.

I'll leave the final review up to Tiangolo.