'auto' support in fetch and fetchFormat

[apalumbo]

In version 1.x 'auto' was supported as fetch format, this PR add it also to version 2.x

[yoadsn]

Hi @apalumbo I am also interested in helping to maintain this.
I think that fetch does not accept auto according to spec - only the fetchFormat.
Right?
See here compare with here

[apalumbo]

Not sure, I mean at the end of the day it is the same parameter f_auto for automatic or f_jpg for jpg
Am I missing something?
@yoadsn

[marnusw]

Thanks @apalumbo. It looks like this was just a types issue because it was supported in the code before. As for fetchFormat vs. format as I recall I couldn't find fetchFormat in the current docs anymore, and the two options have always basically done the same thing so it would make sense that they have silently deprecated one. In this lib it's also an alias of format, both generating f_<value>, so they both do support auto.

[yoadsn]

It translates into the same f_ directive indeed. But, the actual spec indicates only "fetchFormat" accepts auto.
I guess it's a matter of supporting what the code does - and indeed in the code they are used interchangeably (i.e. if not "fetchFormat", take from "format")

[yoadsn]

@marnusw If you follow the links I have posted above (the docs) and choose "JS" flavor - you will see it uses "fetchFormat" for the "auto" value and not "format".

[marnusw]

O, now I see, you're right @yoadsn. Thanks. Still, since it makes no difference in terms of the output I think it's fine for the types to support both in this case.

It's also possible those docs are out of date, because I see the (I assume) newer PHPv2 and Kotlin examples do use a variant of format: auto.

[marnusw]

v2.0.1 is available.