From 4ff1c1aa8811d599d268f9e48f31a4902683fe8e Mon Sep 17 00:00:00 2001
From: Christian Guinard <28689358+christiangnrd@users.noreply.github.com>
Date: Wed, 4 Sep 2024 15:39:14 -0300
Subject: [PATCH] Use dynamic command completions

---
 Cargo.lock         | 12 ++++++++++++
 Cargo.toml         |  3 ++-
 README.md          | 14 +++++++++++++-
 src/bin/juliaup.rs |  5 ++++-
 src/cli.rs         |  2 +-
 5 files changed, 32 insertions(+), 4 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index f8196368..3fc0334e 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -266,6 +266,9 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6d7db6eca8c205649e8d3ccd05aa5042b1800a784e56bc7c43524fde8abbfa9b"
 dependencies = [
  "clap",
+ "clap_lex",
+ "is_executable",
+ "shlex",
 ]
 
 [[package]]
@@ -965,6 +968,15 @@ dependencies = [
  "windows-sys 0.52.0",
 ]
 
+[[package]]
+name = "is_executable"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fa9acdc6d67b75e626ad644734e8bc6df893d9cd2a834129065d3dd6158ea9c8"
+dependencies = [
+ "winapi",
+]
+
 [[package]]
 name = "is_terminal_polyfill"
 version = "1.70.1"
diff --git a/Cargo.toml b/Cargo.toml
index f6ce7650..5789eca1 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -7,6 +7,7 @@ license = "MIT"
 keywords = ["julia"]
 categories = ["command-line-utilities"]
 edition = "2021"
+rust-version = "1.80"
 default-run = "juliaup"
 authors = ["David Anthoff <anthoff@berkeley.edu>"]
 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 = "5.0.1"
 dunce = "1.0"
 serde = { version = "1.0", features = ["derive"] }
diff --git a/README.md b/README.md
index d6bee397..9cd1cde0 100644
--- a/README.md
+++ b/README.md
@@ -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:
@@ -168,6 +167,19 @@ 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
diff --git a/src/bin/juliaup.rs b/src/bin/juliaup.rs
index 1cdbb2f0..43aabd60 100644
--- a/src/bin/juliaup.rs
+++ b/src/bin/juliaup.rs
@@ -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")
diff --git a/src/cli.rs b/src/cli.rs
index ea393760..839dafac 100644
--- a/src/cli.rs
+++ b/src/cli.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`."