nushell/crates/nu-command/src/default_context.rs

use std::{cell::RefCell, rc::Rc};

use nu_protocol::{
    engine::{EngineState, StateWorkingSet},
    Signature,
};

use crate::*;

pub fn create_default_context() -> Rc<RefCell<EngineState>> {
    let engine_state = Rc::new(RefCell::new(EngineState::new()));
    let delta = {
        let engine_state = engine_state.borrow();
        let mut working_set = StateWorkingSet::new(&*engine_state);

        macro_rules! bind_command {
            ( $command:expr ) => {
                working_set.add_decl(Box::new($command));
            };
            ( $( $command:expr ),* ) => {
                $( working_set.add_decl(Box::new($command)); )*
            };
        }

        // TODO: sort items categorically
        #[rustfmt::skip] bind_command!( Alias, Benchmark, BuildString,
        Cd, Cp, Def, Do, Each, ExportDef, External, For, From,
        FromJson, Get, Griddle, Help, Hide, If, Length, Let, LetEnv,
        Lines, Ls, Mkdir, Module, Mv, Open, Ps, Rm, Save, Select,
        Split, SplitChars, SplitColumn, SplitRow, Sys, Table, Touch,
        Use, Where, Wrap );

        // This is a WIP proof of concept
        bind_command!(ListGitBranches, Git, GitCheckout, Source);

        let sig = Signature::build("exit");
        working_set.add_decl(sig.predeclare());
        let sig = Signature::build("vars");
        working_set.add_decl(sig.predeclare());
        let sig = Signature::build("decls");
        working_set.add_decl(sig.predeclare());
        let sig = Signature::build("blocks");
        working_set.add_decl(sig.predeclare());
        let sig = Signature::build("stack");
        working_set.add_decl(sig.predeclare());
        let sig = Signature::build("contents");
        working_set.add_decl(sig.predeclare());

        working_set.render()
    };

    {
        EngineState::merge_delta(&mut *engine_state.borrow_mut(), delta);
    }

    engine_state
}