CLI improvements

[lights0123]

Now that I've started writing my own cargo subcommand as you recommended on the forums, I thought I'd share some of my findings.

cargo-n64/cargo-n64/src/cargo.rs

Line 137 in 1dbff85

// TODO: Add highlighting

You can pass --message-format=json-render-diagnostics instead of just --message-format=json. Then, all warnings will be printed to cargo's stderr with proper formatting, and you can just inherit that to do syntax highlighting.

cargo-n64/cargo-n64/src/cargo.rs

Line 124 in 1dbff85

// Return build artifact

Instead of just grabbing the last artifact, you should grab everything where target.executable exists for when there's multiple binaries, such as in workspaces:

{
  "reason": "compiler-artifact",
  "package_id": "hello-world 1.0.2 (path+file:///path/to/hello-world)",
  "target": {
    "kind": [
      "bin" // Right here
    ],
    "crate_types": [
      "bin"
    ],
    "name": "hello-world",
    "src_path": "/path/to/hello-world/src/main.rs",
    "edition": "2018",
    "doctest": false
  },
  "profile": {
    "opt_level": "0",
    "debuginfo": 2,
    "debug_assertions": true,
    "overflow_checks": true,
    "test": false
  },
  "features": [],
  "filenames": [
    "/path/to/hello-world"
  ],
  "executable": "/path/to/hello-world", // Right here
  "fresh": false
}

You can use cargo_metadata to do that parsing, or whatever JSON parser.

Another thing is that you're requiring the user to pass in a few parameters. What I like to do instead is use the [metadata] section of the Cargo.toml to store that data, so you don't have to keep passing it in. Just thought I'd mention it.