Use dynamic command completions

Author: christiangnrd

Cargo.lock

@@ -7,6 +7,7 @@ license = "MIT"
 keywords = ["julia"]
 categories = ["command-line-utilities"]
 edition = "2021"
+rust-version = "1.80"
 default-run = "juliaup"
 authors = ["David Anthoff <[email protected]>"]
 exclude = [
@@ -27,7 +28,7 @@ codegen-units = 1
 
 [dependencies]
 clap = { version = "4.5", features = ["derive"] }
-clap_complete = "4.5"
+clap_complete = { version = "4.5", features = ["unstable-dynamic"] }
 dirs = "6.0.0"
 dunce = "1.0"
 serde = { version = "1.0", features = ["derive"] }

Cargo.toml

@@ -123,7 +123,6 @@ Here are some of the things you can do with `juliaup`:
 - `juliaup override set --path foo/bar lts` sets a directory override for the path `foo/bar` to the `lts` channel.
 - `juliaup override unset --path foo/bar` removes a directory override for the path `foo/bar`.
 - `juliaup override unset --nonexistent` removes all directory overrides for paths that no longer exist.
-- `juliaup completions bash > ~/.local/share/bash-completion/completions/juliaup` generates Bash completions for `juliaup` and saves them to a file. To use them, simply source this file in your `~/.bashrc`. Other supported shells are `zsh`, `fish`, `elvish` and `powershell`.
 - `juliaup` shows you what other commands are available.
 
 The available system provided channels are:
@@ -169,6 +168,19 @@ the `JULIAUP_DEPOT_PATH` environment variable. Caution: Previous versions of Jul
 Juliaup by default downloads julia binary tarballs from the official server "https://julialang-s3.julialang.org".
 If requested, the environment variable `JULIAUP_SERVER` can be used to tell Juliaup to use a third-party mirror server.
 
+## Shell completions
+
+To generate shell completions, load `COMPLETE=$SHELL juliaup` at shell launch. For example, with bash, it could look like `source <(COMPLETE=bash juliaup)`.
+
+For more specific information on adding completions to your shell, see https://docs.rs/clap_complete/latest/clap_complete/env/index.html
+
+Note: MacOS ships with an ancient version of bash that does not support process substitution. To work around this, you can create a temporary file and `source` that instead like:
+
+```bash
+COMPLETE=bash juliaup > /tmp/juliaup_completion.sh
+source /tmp/juliaup_completion.sh
+```
+
 ## Development guides
 
 For juliaup developers, information on how to build juliaup locally, update julia versions, and release updates

README.md

@@ -1,5 +1,6 @@
 use anyhow::{Context, Result};
-use clap::Parser;
+use clap::{CommandFactory, Parser};
+use clap_complete::CompleteEnv;
 use juliaup::cli::{ConfigSubCmd, Juliaup, OverrideSubCmd, SelfSubCmd};
 use juliaup::command_api::run_command_api;
 #[cfg(not(windows))]
@@ -36,6 +37,8 @@ use juliaup::command_selfuninstall::run_command_selfuninstall_unavailable;
 use log::info;
 
 fn main() -> Result<()> {
+    CompleteEnv::with_factory(|| Juliaup::command()).complete();
+
     human_panic::setup_panic!(
         human_panic::Metadata::new("Juliaup", env!("CARGO_PKG_VERSION"))
             .support("https://github.com/JuliaLang/juliaup")

src/bin/juliaup.rs

@@ -1,7 +1,7 @@
 use clap::{Parser, ValueEnum};
 
 #[derive(Parser)]
-#[clap(name = "Juliaup", version)]
+#[clap(name = "juliaup", version)]
 #[command(
     after_help = "To launch a specific Julia version, use `julia +{channel}` e.g. `julia +1.6`.
 Entering just `julia` uses the default channel set via `juliaup default`."