Added optional depends and optdepends keys

[margual56]

Why?

depends and optdepends are often needed when creating an AUR package. Not "cargo" dependencies, but other programs such as mpv to play videos.

How?

This pull request adds two optional manifest keys: depends and optdepends, which are arrays of strings containing the name of the program's dependencies.

Since they are optional, this version will remain backwards-compatible. Empty arrays will be generated if not present in the Cargo.toml

Possible improvements

• When compiling, cargo warns about "unused manifest keys" (because depends and optdepends are not valid cargo package keys).

[fosskers]

Thanks for this, this would be a good addition!

I had thought that https://lib.rs/crates/cargo-readme did something similar, where it would look for a badges key. Is there not a way to tell Cargo "Hey this is a custom key that I'm using elsewhere, don't worry about it"?

[margual56]

Is there not a way to tell Cargo "Hey this is a custom key that I'm using elsewhere, don't worry about it"?

After some digging, I found that there exists the [package.metadata] table, and indeed with the keys inside that table, no warning is displayed.

I will try to shuffle a couple things and see if I can get stuff parsed from the package.metadata, that should solve the issue :)

[margual56]

That works! I tried to tidy it up somewhat, I hope the formatting and comments are okay.

Open to suggestions 😃

[fosskers]

Fantastic, I'll take a look.

[fosskers]

Github will show the merge status incorrectly, but this was indeed merged! Check the master branch. Once you've signed off, I'll close this PR.

[fosskers]

I've released 1.5.0 with this included.

[margual56]

Nice! Thank you 😊