From 0bedbe55aca667bc3894a88451d6e525b928322c Mon Sep 17 00:00:00 2001
From: Stefan Gehr <stefan@gehr.xyz>
Date: Sun, 14 Jan 2024 13:23:34 +0100
Subject: [PATCH 1/2] Add completions command

The command generates the shell completions file for juliaup.
For example, to generate the completions for Bash and save them to a
file you can run
```
juliaup completions bash > ~/.local/share/bash-completion/completions/juliaup
```
Then you can source this file in your bashrc.
---
 Cargo.lock                 | 10 ++++++++++
 Cargo.toml                 |  1 +
 src/bin/juliaup.rs         |  2 ++
 src/cli.rs                 |  2 ++
 src/command_completions.rs | 22 ++++++++++++++++++++++
 src/lib.rs                 |  1 +
 6 files changed, 38 insertions(+)
 create mode 100644 src/command_completions.rs

diff --git a/Cargo.lock b/Cargo.lock
index 0df08633..fdfd5e21 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -245,6 +245,15 @@ dependencies = [
  "strsim",
 ]
 
+[[package]]
+name = "clap_complete"
+version = "4.4.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "97aeaa95557bd02f23fbb662f981670c3d20c5a26e69f7354b28f57092437fcd"
+dependencies = [
+ "clap",
+]
+
 [[package]]
 name = "clap_derive"
 version = "4.4.7"
@@ -968,6 +977,7 @@ dependencies = [
  "built",
  "chrono",
  "clap",
+ "clap_complete",
  "cli-table",
  "cluFlock",
  "console",
diff --git a/Cargo.toml b/Cargo.toml
index 20bbbd88..9bc43de6 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -27,6 +27,7 @@ codegen-units = 1
 
 [dependencies]
 clap = { version = "4.3.19", features = ["derive"] }
+clap_complete = "4.3.19"
 dirs = "5.0.1"
 dunce = "1.0.4"
 serde = { version = "1.0.175", features = ["derive"] }
diff --git a/src/bin/juliaup.rs b/src/bin/juliaup.rs
index 0626a369..badea44a 100644
--- a/src/bin/juliaup.rs
+++ b/src/bin/juliaup.rs
@@ -2,6 +2,7 @@ use anyhow::{Context, Result};
 use clap::Parser;
 use juliaup::cli::{ConfigSubCmd, Juliaup, OverrideSubCmd, SelfSubCmd};
 use juliaup::command_api::run_command_api;
+use juliaup::command_completions::run_command_completions;
 #[cfg(not(windows))]
 use juliaup::command_config_symlinks::run_command_config_symlinks;
 use juliaup::command_config_versionsdbupdate::run_command_config_versionsdbupdate;
@@ -111,5 +112,6 @@ fn main() -> Result<()> {
             #[cfg(not(feature = "selfupdate"))]
             SelfSubCmd::Uninstall {} => run_command_selfuninstall_unavailable(),
         },
+        Juliaup::Completions { shell } => run_command_completions(&shell),
     }
 }
diff --git a/src/cli.rs b/src/cli.rs
index 5310eccd..4c6a7e18 100644
--- a/src/cli.rs
+++ b/src/cli.rs
@@ -47,6 +47,8 @@ pub enum Juliaup {
     Info {},
     #[clap(subcommand, name = "self")]
     SelfSubCmd(SelfSubCmd),
+    /// Generate tab-completion scripts for your shell
+    Completions { shell: String },
     // This is used for the cron jobs that we create. By using this UUID for the command
     // We can identify the cron jobs that were created by juliaup for uninstall purposes
     #[cfg(feature = "selfupdate")]
diff --git a/src/command_completions.rs b/src/command_completions.rs
new file mode 100644
index 00000000..291ee04a
--- /dev/null
+++ b/src/command_completions.rs
@@ -0,0 +1,22 @@
+use crate::cli;
+use anyhow::bail;
+use anyhow::Result;
+use clap::CommandFactory;
+use clap_complete::Shell;
+use cli::Juliaup;
+use std::io;
+use std::str::FromStr;
+
+pub fn run_command_completions(shell: &str) -> Result<()> {
+    if let Ok(shell) = Shell::from_str(shell) {
+        clap_complete::generate(
+            shell,
+            &mut Juliaup::command(),
+            "juliaup",
+            &mut io::stdout().lock(),
+        );
+    } else {
+        bail!("'{}' is not a supported shell.", shell)
+    }
+    Ok(())
+}
diff --git a/src/lib.rs b/src/lib.rs
index 6b5c2f72..92675479 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -3,6 +3,7 @@ use anyhow::Context;
 pub mod cli;
 pub mod command_add;
 pub mod command_api;
+pub mod command_completions;
 pub mod command_config_backgroundselfupdate;
 pub mod command_config_modifypath;
 pub mod command_config_startupselfupdate;

From de02146c4b968d654e540f7ca8ad2b7388e91fc5 Mon Sep 17 00:00:00 2001
From: Stefan Gehr <stefan@gehr.xyz>
Date: Sun, 14 Jan 2024 13:26:54 +0100
Subject: [PATCH 2/2] Add info about the completions command to the README

---
 README.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/README.md b/README.md
index b02b8d2c..4fc6e709 100644
--- a/README.md
+++ b/README.md
@@ -109,6 +109,7 @@ 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: