feat: Adding a json output that surfaces the attributes of the modules

[graysonarts]

I love this tool, but I needed an easy way to parse the output, so created a json printer. I tried to follow the pattern set up by the tree printer to implement the json output.

cargo fmt, cargo clippy, and cargo test all come back clean.

Here is what the output looks like. I didn't pretty print it because one can always use jq to format. Also, I didn't wrap the attributes in #[cfg(...)] like you do in tree. If that's a blocker, I can make that change easy enough. The path is also a full path as that's how it's stored internally. For my consumption, I'm planning to strip that based on the directory in which it was invoked after the fact, but if you'd prefer it to do relative paths, just let me know.

[
{"module":"cargo_modules","path":"/Users/grayson/code/contrib/cargo-modules/src/lib.rs","kind":"crate","visibility":"pub","attributes":[]}
,{"module":"cargo_modules::theme","path":"/Users/grayson/code/contrib/cargo-modules/src/theme.rs","kind":"mod","visibility":"pub(crate)","attributes":[]}
,{"module":"cargo_modules::theme::tree","path":"/Users/grayson/code/contrib/cargo-modules/src/theme/tree.rs","kind":"mod","visibility":"pub(crate)","attributes":[]}
,{"module":"cargo_modules::theme::graph","path":"/Users/grayson/code/contrib/cargo-modules/src/theme/graph.rs","kind":"mod","visibility":"pub(crate)","attributes":[]}
,{"module":"cargo_modules::target","path":"/Users/grayson/code/contrib/cargo-modules/src/target.rs","kind":"mod","visibility":"pub(crate)","attributes":[]}
,{"module":"cargo_modules::printer","path":"/Users/grayson/code/contrib/cargo-modules/src/printer.rs","kind":"mod","visibility":"pub(crate)","attributes":[]}
,{"module":"cargo_modules::printer::tree","path":"/Users/grayson/code/contrib/cargo-modules/src/printer/tree.rs","kind":"mod","visibility":"pub(crate)","attributes":[]}
,{"module":"cargo_modules::printer::json","path":"/Users/grayson/code/contrib/cargo-modules/src/printer/json.rs","kind":"mod","visibility":"pub(crate)","attributes":[]}
,{"module":"cargo_modules::printer::graph","path":"/Users/grayson/code/contrib/cargo-modules/src/printer/graph.rs","kind":"mod","visibility":"pub(crate)","attributes":[]}
,{"module":"cargo_modules::orphans","path":"/Users/grayson/code/contrib/cargo-modules/src/orphans.rs","kind":"mod","visibility":"pub(crate)","attributes":[]}
,{"module":"cargo_modules::graph","path":"/Users/grayson/code/contrib/cargo-modules/src/graph.rs","kind":"mod","visibility":"pub(crate)","attributes":[]}
,{"module":"cargo_modules::graph::walker","path":"/Users/grayson/code/contrib/cargo-modules/src/graph/walker.rs","kind":"mod","visibility":"pub(crate)","attributes":[]}
,{"module":"cargo_modules::graph::util","path":"/Users/grayson/code/contrib/cargo-modules/src/graph/util.rs","kind":"mod","visibility":"pub(crate)","attributes":[]}
,{"module":"cargo_modules::graph::orphans","path":"/Users/grayson/code/contrib/cargo-modules/src/graph/orphans.rs","kind":"mod","visibility":"pub(crate)","attributes":[]}
,{"module":"cargo_modules::graph::node","path":"/Users/grayson/code/contrib/cargo-modules/src/graph/node.rs","kind":"mod","visibility":"pub(crate)","attributes":[]}
,{"module":"cargo_modules::graph::node::visibility","path":"/Users/grayson/code/contrib/cargo-modules/src/graph/node/visibility.rs","kind":"mod","visibility":"pub(crate)","attributes":[]}
,{"module":"cargo_modules::graph::node::attr","path":"/Users/grayson/code/contrib/cargo-modules/src/graph/node/attr.rs","kind":"mod","visibility":"pub(crate)","attributes":[]}
,{"module":"cargo_modules::graph::edge","path":"/Users/grayson/code/contrib/cargo-modules/src/graph/edge.rs","kind":"mod","visibility":"pub(crate)","attributes":[]}
,{"module":"cargo_modules::graph::builder","path":"/Users/grayson/code/contrib/cargo-modules/src/graph/builder.rs","kind":"mod","visibility":"pub(crate)","attributes":[]}
,{"module":"cargo_modules::options","path":"/Users/grayson/code/contrib/cargo-modules/src/options.rs","kind":"mod","visibility":"pub","attributes":[]}
,{"module":"cargo_modules::options::general","path":null,"kind":"mod","visibility":"pub","attributes":[]}
,{"module":"cargo_modules::options::project","path":null,"kind":"mod","visibility":"pub","attributes":[]}
,{"module":"cargo_modules::options::generate","path":null,"kind":"mod","visibility":"pub","attributes":[]}
,{"module":"cargo_modules::options::generate::json","path":null,"kind":"mod","visibility":"pub","attributes":[]}
,{"module":"cargo_modules::options::generate::tree","path":null,"kind":"mod","visibility":"pub","attributes":[]}
,{"module":"cargo_modules::options::generate::graph","path":null,"kind":"mod","visibility":"pub","attributes":[]}
,{"module":"cargo_modules::options::graph","path":null,"kind":"mod","visibility":"pub","attributes":[]}
,{"module":"cargo_modules::generate","path":"/Users/grayson/code/contrib/cargo-modules/src/generate.rs","kind":"mod","visibility":"pub","attributes":[]}
,{"module":"cargo_modules::generate::tree","path":"/Users/grayson/code/contrib/cargo-modules/src/generate/tree.rs","kind":"mod","visibility":"pub","attributes":[]}
,{"module":"cargo_modules::generate::json","path":"/Users/grayson/code/contrib/cargo-modules/src/generate/json.rs","kind":"mod","visibility":"pub","attributes":[]}
,{"module":"cargo_modules::generate::graph","path":"/Users/grayson/code/contrib/cargo-modules/src/generate/graph.rs","kind":"mod","visibility":"pub","attributes":[]}
,{"module":"cargo_modules::commands","path":"/Users/grayson/code/contrib/cargo-modules/src/commands.rs","kind":"mod","visibility":"pub","attributes":[]}
]```

[regexident]

Hey @graysonarts, this looks great!

Since the absolute paths cause problems with unit tests (since the working directory on CI differs from your setup) it would probably be desirable (at least for testing).

Relative paths might however not be suitable for --with-externs, which would produce paths outside of $PWD. Does generate json include extern declarations? 🤔

Maybe the generate json command should have a --absolute-paths or --relative-paths option? Not exactly sure which would make for a better default, absolute or relative paths.

[graysonarts]

Relative paths might however not be suitable for --with-externs, which would produce paths outside of $PWD. Does generate json include extern declarations? 🤔

Oh, I haven't tried --with-externs. I'll do some testing for it and see what is does. I didn't change any of the generation code, so it should work like generate tree does, but I don't know for sure. Do you have a sample repo that uses externs that I can test against?

Maybe the generate json command should have a --absolute-paths or --relative-paths option? Not exactly sure which would make for a better default, absolute or relative paths.

My guess for most useful default would be relative paths with --absolute-paths option to override it, so I'll go that route if you are okay with that.

[regexident]

Oh, I haven't tried --with-externs. I'll do some testing for it and see what is does. I didn't change any of the generation code, so it should work like generate tree does, but I don't know for sure. Do you have a sample repo that uses externs that I can test against?

The --with-externs (when used with --with-uses) will also generate nodes/edges for external symbols used by the crate when running generate graph.

My guess for most useful default would be relative paths with --absolute-paths option to override it, so I'll go that route if you are okay with that.

Sounds good to me!

As for testing I'd say having a single test for the "absolute path to relative path" logic should do. No need to duplicate the tests, especially as the absolute paths would cause issues anyway.

[regexident]

@graysonarts you may want to rebase this branch onto main as it fixes a bunch of rust-analyzer breakage.

[graysonarts]

Will do! Sorry this has taken so long to get across the finish line. I hope to have time to work on it again soon.

…

[regexident]

I'm gonna close this due to inactivity for now. Feel free to request a re-open once it takes up steam again though. 🙂