crates-language-server

A language server for Cargo.toml's dependencies.

Features ✨

• Diagnostic Hints - show hints for latest version for every dependency version (that is not the latest).

• Info on Hover - show info about a create on hover in this format:

  <NAME>: <LATEST_VERSION>
  
  <AVAILABLE_FEATURES>
  
  <DESCRIPTION>
  

• Code Actions - a code action for updating a dependency version to latest.

• Version Completion - open a version's quotation mark ("), and you'll be presented with a list of different granularities for the latest version, e.g., for a crate with the latest version 0.1.3, you'll be offered with the completions: [ 0.1.3, 0.1, 0 ].

• Features Completion - open a features' quotation mark inside the features array, and you'll be presented with a list of a crate's available features.

• Goto definition opens docs.rs - invoke a goto definition event on a dependency name, and the crate's docs.rs page will be opened in your browser.

Usage

Prerequisites

The bellow requirements are only when building from source or using cargo install (i.e., you don't need these if you use the provided Nix flake).

Building

This program uses nightly features, thus requiring using Nightly Rust to compile.

• Nightly rust

Also, this program vendors OpenSSL, which requires the following to build:

• make
• Perl
• a C compiler, like GCC

Note, the above are quite common, so you might want to check if you have them before installing.

Installation

Using git and cargo build

Clone this repository:

git clone https://github.com/rotmh/crates-language-server.git

Then build the project:

cd crates-language-server
cargo build --release

Finally, make sure to put it somewhere in your $PATH.

Using a Nix Flake

Add this repository as an input:

inputs = {
  # ...

  crates-ls.url = "github:rotmh/crates-language-server";
};

Then in the system packages (NixOS) or the home packages (home-manager):

[
  # ...

  (inputs.crates-ls.packages.${pkgs.system}.default)
]

Finally, rebuild your system.

NOTE: I will soon add this to crates.io and nixpkgs.

Editor Integration

Helix

Define a new language server:

[language-server.crates-ls]
command = "crates-language-server"

Note: to use the above snippet, you must have the binary in your $PATH, if you don't, you can also specify the full path to the binary.

Then define a language for Cargo.toml, that uses this language server:

[[language]]
name = "crates"
scope = "source.toml"
file-types = [{ glob = "Cargo.toml" }]
injection-regex = "toml"
grammar = "toml"
language-servers = [ "crates-ls" ]  # you can also add taplo here

Finally, we want to have definitions for highlights and such, thus we need to have an entry for the crates language in the Helix runtime directory.

In your config directory (where you have your config.toml for helix; $HOME/.config/helix in Linux), add a runtime/queries/crates/ directory, and copy these files there. Essentially what we do is copy the toml queries to a queries definition for our language (crates).

Neovim

Know how to integrate this LSP with neovim? Please issue a PR :)

VS Code

Know how to integrate this LSP with VS Code? Please issue a PR :)

---

Know how to integrate this LSP with another editor? Your PR will be appreciated!

Technicalities, for the interested

crates.io's API

This project uses both crates.io's API, and the sparse index.

The API comes with limitations, notably a rate limit (1 request per second). This project respects this rate limit, and does not perform more than 1 request per second.

This limitation does not impacts the performance of the tool, because the API is only used for the crates' descriptions (and the sparse index, which is used for the rest of the crates data, does not enforce a rate limit).

Contributions

PRs, issues, suggestions, and ideas are all appreciated and very welcome :)

License

This project is licensed under MIT.