ChaosStudyGroup/em-refactor

Extract method and Box field refactorings for Rust

Setup

Requirements

• Rust - https://www.rust-lang.org/tools/install

Steps

1. The rustc-dev component is required for compiling this repo, and it can be added to the nightly toolchain using:

rustup component add --toolchain nightly-2020-04-15 rustc-dev

2. Compile the refactoring tool by running the following command in the root folder of this repository:

cargo build --bins --release

Setup (VS Code)

Requirements

• Run Step 1 & 2 from setup
• Node.js - https://nodejs.org/en/
• Visual Studio Code - https://code.visualstudio.com

Steps

• Run npm install in the ./em-refactor-ls folder
• Open Visual Studio Code in the ./em-refactor-ls folder: code em-refactor-ls
• Run the build task (Ctrl+Shift+B)
• Debug the extension (Debug View -> Launch client)
• Configure settings in the new window that launched
  • Open the VS Code extension settings (File->Preferences->Settings) named EM refactoring
  • Set the "Refactoring Cargo.toml path" setting to the absolute path to the top level Cargo.toml file in this repo ( it will be <git repo folder> + /Cargo.toml )

Limitations

• VS Code must be opened at the root folder of the Rust project
• The project must compile successfully
• Unicode characters are not supported
• The ``?'' operator is not supported
• All files must be saved before invoking the refactoring from VS Code

Refactoring from the terminal

Candidates and refactorings can be run either in the current directory, or by setting the --target-dir="path" option

Candidates:

cargo-em-refactor candidates <box-field/extract-method> [--target-dir=PATH]

./target/release/cargo-em-refactor candidates box-field --target-dir="../path/to/project"
./target/release/cargo-em-refactor candidates extract-method

Refactoring:

cargo-em-refactor refactor <box-field/extract-block/extract-method/...> <FILE> <SELECTION> [--target-dir=PATH]

./target/release/cargo-em-refactor refactor box-field refactor-lib/src/refactorings/visitors/struct_field_access_expression_collector.rs 1242:1255

./em-refactor-examples -- Examples in rust

This project should contain a list of valid refactorings that can be used for unit tests.

Each refactoring example should contain the code before, after and the arguments passed to the refactoring tool. The arguments must contain refactoring definition name (e.g. 'extract-method') and selection (from and to). Other arguments might be required depending on the actual refactoring.

So for the testcase 'extract-method-01', the following files are required

• extract-method-01.rs
  • The code before refactoring
• extract-method-01_after.rs
  • The expected code after refactoring
• extract-method-01.json
  • The arguments to be passed

If the test is expected to fail, then the file ending with _after.rs is not required.

TODO: When searching automatically for candidates that can be refactored, the arguments should not be required. How can that be tested automatically?

./em-refactor-lib -- Refactor library

The project containing the actual refactorings.

There are two executable files, one from main.rs and one from driver.rs.

main.rs calls cargo check with the executable from driver.rs as argument. The RUSTC_WRAPPER flag is set to 1 when calling cargo. Cargo then calls the executable with the same argument as if it was calling rustc. We can then pass callbacks when we run rustc_driver::run_compiler.