Cargo Extension

Tombi itself is written in Rust, and we want to make the Rust development experience even better 🦀

Experimentally, we provide additional features when editing Cargo.toml files.

Supported Features

Code Completion

The extension provides intelligent code completion for Cargo.toml files.

Crate Version Completion

Get version suggestions when specifying crate versions:

[dependencies]
serde = "1.0.130"  # <- version suggestions appear here
tokio = { version = "1.21.0" }  # <- also here

Features:

• Fetches available versions from crates.io
• Shows up to 100 versions sorted newest first
• Works in all dependency sections (dependencies, dev-dependencies, build-dependencies, workspace.dependencies)

Crate Feature Completion

Get feature suggestions when specifying crate features:

[dependencies]
serde = { version = "1.0", features = ["derive"] }  # <- feature suggestions
tokio = { version = "1.21", features = ["full", "net"] }  # <- in array

Features:

• Fetches available features from:
  • crates.io for registry dependencies
  • Local Cargo.toml for path dependencies
  • Workspace Cargo.toml for workspace dependencies
• Shows feature dependencies in documentation
• Filters out already selected features
• default feature shown first, features starting with _ shown last

Go to Definition

For example, suppose you have a Cargo.toml like the one below:

Go to workspace/crate definition from dependencies

[dependencies]
serde = { workspace = true }
tombi-ast = { workspace = true }

In this case, when your cursor is on workspace, executing "Go to Definition" will navigate you to the workspace definition or to the crate definition managed by the workspace.

In the example above, for serde (an external crate), you'll be navigated to the workspace definition, while for tombi-ast (a crate managed by the workspace), you'll be navigated to the crate definition.

Go to crate definition from workspace.dependencies

[workspace.dependencies]
tombi-ast = { path = "crates/tombi-ast" }

In this case, when your cursor is on path, executing "Go to Definition" will navigate you to the crate definition.

Go to Declaration

[dependencies]
serde = { workspace = true }
tombi-ast = { workspace = true }

In this case, when your cursor is on workspace, executing "Go to Declaration" will navigate you to the crate definition.

Code Actions

When working with Cargo.toml files, additional code actions are available.

Inherit from Workspace

Convert package fields to inherit from workspace configuration:

# Before
[package]
version = "1.0.0"
authors = ["John Doe"]

# After applying "Inherit from workspace"
[package]
version.workspace = true
authors.workspace = true

Inherit Dependency from Workspace

Convert dependencies to use workspace versions:

# Before
[dependencies]
serde = "1.0"

# After applying "Inherit dependency from workspace"
[dependencies]
serde = { workspace = true }

Convert Dependency to Table Format

Transform simple string dependencies to table format for adding additional fields:

# Before
[dependencies]
serde = "1.0"

# After applying "Convert to table format"
[dependencies]
serde = { version = "1.0" }

Add to Workspace and Inherit Dependency

Promote versioned dependencies into the workspace while switching members to use the shared entry:

# Before
# Workspace Cargo.toml
[workspace.dependencies]
# (serde not present)

# Member Cargo.toml
[dependencies]
serde = "1.0"

# After applying "Add to Workspace and Inherit Dependency"
[workspace.dependencies]
serde = "1.0"

[dependencies]
serde = { workspace = true }

The workspace entry keeps the original requirement, and the member now follows the workspace-managed version.

Document Links

The extension enriches Cargo.toml with contextual document links so you can jump directly to related resources:

• Entries in [workspace.members] and [workspace.default-members] open the corresponding member crate's Cargo.toml.
• Dependencies in member manifests surface links to the workspace definition (when workspace = true), local path manifests, git repositories, custom registries, or crates.io when applicable.
• [workspace.dependencies] entries provide quick access both to the workspace declaration and the external source (registry/git/crates.io).
• Fields such as package.workspace, lints.workspace, and [bin] targets link back to their workspace counterparts or the referenced source file for faster navigation.