From 69c153ba30fc1c83711fb0a56ea35293d7bd0f3f Mon Sep 17 00:00:00 2001
From: Nicky Meuleman <nicky.meuleman+github@gmail.com>
Date: Tue, 17 Oct 2023 15:16:18 +0200
Subject: [PATCH] add shell completion generation (#100)

* add shell completion generation

* remove extra printline

* use long form only for completion arg

Co-authored-by: Trent <2771466+tbillington@users.noreply.github.com>

---------

Co-authored-by: Trent <2771466+tbillington@users.noreply.github.com>
---
 Cargo.lock        | 10 ++++++++++
 kondo/Cargo.toml  |  1 +
 kondo/src/main.rs | 18 +++++++++++++++++-
 3 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/Cargo.lock b/Cargo.lock
index e574859..2b07598 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -120,6 +120,15 @@ dependencies = [
  "strsim",
 ]
 
+[[package]]
+name = "clap_complete"
+version = "4.4.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e3ae8ba90b9d8b007efe66e55e48fb936272f5ca00349b5b0e89877520d35ea7"
+dependencies = [
+ "clap",
+]
+
 [[package]]
 name = "clap_derive"
 version = "4.3.2"
@@ -229,6 +238,7 @@ name = "kondo"
 version = "0.7.0"
 dependencies = [
  "clap",
+ "clap_complete",
  "kondo-lib",
 ]
 
diff --git a/kondo/Cargo.toml b/kondo/Cargo.toml
index 849f281..1d8d6bb 100644
--- a/kondo/Cargo.toml
+++ b/kondo/Cargo.toml
@@ -20,6 +20,7 @@ edition = "2021"
 
 [dependencies]
 clap = { version = "4", features = ["derive"] }
+clap_complete = "4"
 
 [dependencies.kondo-lib]
 path = "../kondo-lib"
diff --git a/kondo/src/main.rs b/kondo/src/main.rs
index f98e3e9..aac3c9e 100644
--- a/kondo/src/main.rs
+++ b/kondo/src/main.rs
@@ -8,7 +8,8 @@ use std::{
     sync::mpsc::{Receiver, Sender, SyncSender},
 };
 
-use clap::Parser;
+use clap::{Command, CommandFactory, Parser};
+use clap_complete::{generate, Generator, Shell};
 
 use kondo_lib::{
     dir_size, path_canonicalise, pretty_size, print_elapsed, scan, Project, ScanOptions,
@@ -49,6 +50,10 @@ struct Opt {
     #[arg(short, long, value_parser = parse_age_filter, default_value = "0d")]
     older: u64,
 
+    /// Generates completions for the specified shell
+    #[arg(long = "completions", value_enum)]
+    generator: Option<Shell>,
+
     /// If there is no input, defaults to yes
     #[arg(short, long)]
     default: bool,
@@ -285,9 +290,20 @@ fn interactive_prompt(
     }
 }
 
+fn print_completions<G: Generator>(gen: G, cmd: &mut Command) {
+    generate(gen, cmd, cmd.get_name().to_string(), &mut stdout());
+}
+
 fn main() -> Result<(), Box<dyn Error>> {
     let mut opt = Opt::parse();
 
+    if let Some(generator) = opt.generator {
+        let mut cmd = Opt::command();
+        eprintln!("Generating completion file for {generator:?}...");
+        print_completions(generator, &mut cmd);
+        return Ok(());
+    }
+
     if opt.quiet > 0 && !opt.all {
         eprintln!("Quiet mode can only be used with --all.");
         std::process::exit(1);