# GSoC 2024 Cargo Completions Notes

General availability: https://lettucemeet.com/l/e49bd

Parent issues
- https://github.com/clap-rs/clap/issues/3166
- https://github.com/clap-rs/clap/tree/master/clap_complete/src/dynamic
- https://github.com/rust-lang/cargo/issues/6645

Ed's work schedule: 9am Central US to 5pm Central US
Ed's extended schedule: 7pm-9pm (on a when available basis)

## Syncs

### 2024-05-22

Starting point: https://github.com/clap-rs/clap/issues/3920

### 2024-05-31

- Review how other custom completers design their dynamic completion parts and design a good dynamic completion: https://github.com/clap-rs/clap/discussions/5512

- Confirm the features of the existing completion scripts for `Cargo` commands. These need to be considered when designing the dynamic completion for `clap_complete`.

**Q:** For value completion in Cargo commands, many require executing some functions to obtain the possible values list. We might need to implement the `possible_values` method of the `TypedValueParser` trait for `Fn(&str) -> Result<T, E> + Clone + Send + Sync + 'static` to support user-defined closures or functions for obtaining possible values.

### 2024-06-07

- Research: https://github.com/clap-rs/clap/discussions/5512
- https://hackmd.io/aDFjwmx0SSm_oZeaoGeWtQ
- something like this was done before and stopped in https://github.com/clap-rs/clap/pull/5018
- Maybe shift focus to just `--option value`

### 2024-06-21

Three branches
- shells (zsh, elvish)
- options
- then multiple options
- hidden https://github.com/clap-rs/clap/issues/3951
- then https://github.com/clap-rs/clap/issues/5058

### 2024-07-05

- Adding of shells needs feature comparison with static completion shell support and either not close out issue or create separate issues for things not done in PRs
- Added documentation task to tracking issue
- For https://github.com/clap-rs/clap/pull/5539
- Suggested holding off on extra ways of doing values so we can close out the PR

### 2024-07-12

### 2024-07-19

- powershell
- https://github.com/clap-rs/clap/pull/5564
- move forward without tests
- having tests is better than the static completions
- better to crowdsource with powershell users
- Start asking for testing
- https://github.com/clap-rs/clap/pull/5539
- https://github.com/clap-rs/clap/pull/5564
- hidden stuff not required but nice as it shows the value
- won't wait for users, handled async
- Focus:
- option-values
- hidden
- powershell
- Next:
- multiple values
- `=`?
- Correctly handle appending a space?
- epage: break this out into an issue

#### 2024-07-26

- Next:
- https://github.com/clap-rs/clap/issues/1232
- epage:
- Put up `unstable-ext` PR
- Audit completion issues

#### 2024-08-02

- Back to school Aug 9th
- Next:
- Custom completers
- Test it out in Cargo

trait CustomCompleter {
    fn completions(&self) -> Vec<CompletionCandidate>;
}

impl<F> CustomCompleter for F 
where F: Fn() -> Vec<CompletionCandidate> {
    fn completions(&self) -> Vec<CompletionCandidate> {
        (self)()
    }
}

#### 2024-08-16

- `cargo <cmd>`
- Complete built-ins, third-party subcommand, aliases (https://doc.rust-lang.org/cargo/reference/config.html#alias)
- `cargo <cmd> <args>` is separate and needs https://github.com/clap-rs/clap/issues/5653
- `cargo <cmd> <args>`
- Not feature parity?
- switch to env variable-driven completions
- decide what shells are supported / documented
- shell support
- option: only what we do today
- option: only document what we do today
- option: support all
- explain why we chose what we did
- test plan
- `completest` for autoamted tests
- end-user acceptance testing / call-for-testing
- Switch to env variables
- Don't replace manual scripts until stabilization
- Make it only available on nightly: https://docs.rs/cargo/latest/cargo/util/context/struct.GlobalContext.html#structfield.nightly_features_allowed
- https://docs.rs/cargo/latest/cargo/core/features/fn.channel.html
- call-for-testing: https://doc.crates.io/contrib/process/unstable.html#pre-stabilization

- Initial cargo PR
- uses env variables
- only works on nightly
- doesn't use argvaluecompleter yet
- `unstable.md` documentation
- Open question: unstable feature of clap
- Tracking issue tasks
- Each argvaluecompleter
- Replacing the manual completion files

#### 2024-08-26

- cargo PR
- completest timeout override
- Between these lines use CompleteEnv:
- https://github.com/rust-lang/cargo/blob/f2d1e37b56529f5200c3861be8b3d1c24f62c135/src/bin/cargo/main.rs#L21-L23
- Check nightly like: https://docs.rs/cargo/latest/src/cargo/util/context/mod.rs.html#325
- env var name: `CARGO_COMPLETE`

#### 2024-08-30

- timeout PR has one issue in it
- Does cargo need timeout when using `CompleteEnv`
- Action item: create draft PR against rust-lang/cargo with where you are at
- Welcome to https://github.com/rust-lang/cargo/wiki/Office-Hours

#### 2024-09-09

- Testing in cargo
- `CompleteEnv`, needs end to end
- Maybe needs all shells for registration command?
- Otherwise, only needs one shell and one end-to-end test
- If only 1-5 tests, don't need a file per sub-feature or shell