prototype

Cargo.toml

@@ -1,22 +1,17 @@
 [package]
 name = "cargo-shear"
-version = "0.6.1"
+version = "0.0.1"
 edition = "2021"
 description = "Detect and remove unused dependencies from Cargo.toml"
 authors = ["Boshen <boshenc@gmail.com>"]
 repository = "https://github.com/Boshen/cargo-shear"
-keywords = []
-categories = []
+keywords = ["cargo", "udeps", "machete", "unused", "dependencies"]
+categories = ["development-tools", "development-tools::cargo-plugins"]
 license = "MIT"
 readme = "README.md"
 
 [dependencies]
 walkdir = "2.5.0"
-
-[profile.release]
-opt-level = 3
-lto = "fat"
-codegen-units = 1
-strip = "symbols"
-debug = false
-panic = "abort"
+cargo_metadata = "0.18.1"
+cargo_toml = "0.19.2"
+syn = { version = "2", features = ["full", "visit"] }

README.md

@@ -2,7 +2,28 @@
 
 Detect and remove unused dependencies from `Cargo.toml` in Rust projects.
 
+## Technique
+
+1. use the `cargo_metadata` crate to list all dependencies specified in `[workspace.dependencies]` and `[dependencies]`
+2. iterate through all package targets to locate all Rust files
+3. use `syn` to parse these Rust files and extract imports
+4. identify the difference between the imports and the package dependencies
+
+## False positives (to be solved):
+
+* macros
+  * how can imports be collected from macros? e.g. in `println!({}, foo::bar)`, `foo` is a macro token instead of an identifier
+  * can we run some other command and get the macro expanded source to parse?
+  * is there an API for getting imports instead of parsing?
+
+## Improvements
+
+* add a CLI, preferably [bpaf](https://docs.rs/bpaf/latest/bpaf/index.html)
+* make the reporting more granular for `[dependencies]`, `[dev-dependencies]` and `[build-dependencies]`
+
 ## Prior Arts
 
 * https://github.com/est31/cargo-udeps
 * https://github.com/bnjbvr/cargo-machete
+
+## Trophy Cases

justfile

@@ -9,6 +9,12 @@ init:
 watch command:
   cargo watch -x '{{command}}'
 
+build-release:
+  cargo build --release
+
+run-release command:
+  ./target/release/cargo-shear {{command}}
+
 fmt:
   cargo fmt
   taplo format