add dependency feature

[Luke-zhang-04]

Add dependency field

[Luke-zhang-04]

I've gotten started but I'm not sure if my code will even work. I haven't had the time to test any of it.

My idea is that we can store all the package manager info in a hashmap or something similar (kind of like the define_languages macro). I've stolen some code from license.rs too.

[o2sh]

@Luke-zhang-04, I pushed your implementation a little further; it now compiles.

I think your design works well and can be extended to more package managers without difficulties. A thorough review will be done once the feature is usable (for npm at least).

Looking forward to merge your PR 💯

[Luke-zhang-04]

To clarify, an impl is the same as a class right?

[o2sh]

From here

💡 When we discussed about C-like structs, I mentioned that those are similar to classes in OOP languages but without their methods. impls are used to define methods for Rust structs and enums.

[o2sh]

The cargo fmt -- --check is failing because a .rustfmt.toml was added to o2sh::master branch; if you merge this branch with yours and cargo fmt, you should get a diff.

[Luke-zhang-04]

[o2sh]

Well done @Luke-zhang-04
With 369506c, I tried to improve it a bit with better error handling and file separation.

[spenserblack]

Thanks for your PR! This looks like it could be a pretty cool feature!

Left a few notes.

[Luke-zhang-04]

Is there a reason all the requested changes are marked as outdated?

[o2sh]

Is there a reason all the requested changes are marked as outdated?

@spenserblack started his review before 369506c where I moved most of the files.
Except for the two comments regarding catching errors when parsing files, the rest of his remarks still apply.

[Luke-zhang-04]

I think I fixed everything in the review 👍

[Luke-zhang-04]

The new things I added in CONTRIBUTING.md seem like they belong in the wiki. Or I can remove the examples.

[spenserblack]

Thanks for making all those changes! And thanks for updating the contributing guidelines!

I'm approving this overall, but I left a couple notes to catch edge-cases when the dependencies key isn't defined.

[Luke-zhang-04]

I fixed the no dependency thing in 1d6d95b but I don't think I did it in the best way. I'm not sure though.

[Luke-zhang-04]

I think that's really it.

[o2sh]

Thanks a lot for fixing the go module parser 🙏

[o2sh]

The go module parser was still broken, this seems to work:

pub fn go_modules(contents: &str) -> Result<usize> {
    let mut count = 0;
    let mut start = false;
    for line in contents.lines() {
        if line.contains("require") {
            start = true;
            continue;
        }

        if start && line.contains(')') {
            break;
        }

        if start {
            count += 1;
        }
    }

    Ok(count)
}