feat: Implement shell completion using clap_complete

feat: Add shell completion instructions to README

fix: Make completion field public and remove unused import

refactor: Remove unused `Shell` import from `clap_complete`

fix: Add missing completion field to simple_speedtest example

Author: code-inflation

Cargo.toml

@@ -20,3 +20,4 @@ serde = { version = "1.0.219", features = ["derive"] }
 csv = "1.3.0"
 serde_json = "1.0"
 indexmap = "2.7.0"
+clap_complete = "4.5"

README.md

@@ -58,6 +58,32 @@ Example usage:
 Example with json-pretty output:  
 [![asciicast](https://asciinema.org/a/P6IUAADtaCq3bT18GbYVHmksA.svg)](https://asciinema.org/a/P6IUAADtaCq3bT18GbYVHmksA)
 
+### Shell Completion
+
+`cfspeedtest` supports generating shell completion scripts. Use the `--generate-completion` flag followed by your shell name (e.g., `bash`, `zsh`, `fish`, `powershell`, `elvish`).
+
+Example for bash (add to `~/.bashrc` or similar):
+```sh
+cfspeedtest --generate-completion bash > ~/.local/share/bash-completion/completions/cfspeedtest
+# Or, if you don't have a completions directory set up:
+# source <(cfspeedtest --generate-completion bash)
+```
+
+Example for zsh (add to `~/.zshrc` or similar):
+```sh
+# Ensure your fpath includes a directory for completions, e.g., ~/.zfunc
+# mkdir -p ~/.zfunc
+# echo 'fpath=(~/.zfunc $fpath)' >> ~/.zshrc
+cfspeedtest --generate-completion zsh > ~/.zfunc/_cfspeedtest
+# You may need to run compinit:
+# autoload -U compinit && compinit
+```
+
+Example for fish:
+```sh
+cfspeedtest --generate-completion fish > ~/.config/fish/completions/cfspeedtest.fish
+```
+
 
 ## Development
 

examples/simple_speedtest.rs

@@ -16,6 +16,7 @@ fn main() {
         nr_latency_tests: 20,
         max_payload_size: PayloadSize::M10,
         disable_dynamic_max_payload_size: false,
+        completion: None,
     };
 
     let measurements = speed_test(reqwest::blocking::Client::new(), options);

src/lib.rs

@@ -6,6 +6,7 @@ use std::fmt;
 use std::fmt::Display;
 
 use clap::Parser;
+use clap_complete::Shell;
 use speedtest::PayloadSize;
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
@@ -80,6 +81,10 @@ pub struct SpeedTestCLIOptions {
     /// Test upload speed only
     #[arg(long, conflicts_with = "download_only")]
     pub upload_only: bool,
+
+    /// Generate shell completion script for the specified shell
+    #[arg(long = "generate-completion", value_enum)]
+    pub completion: Option<Shell>,
 }
 
 impl SpeedTestCLIOptions {

src/main.rs

@@ -1,14 +1,28 @@
 use cfspeedtest::speedtest;
 use cfspeedtest::OutputFormat;
 use cfspeedtest::SpeedTestCLIOptions;
-use clap::Parser;
+use clap::{CommandFactory, Parser};
+use clap_complete::generate;
+use std::io;
 use std::net::IpAddr;
 
 use speedtest::speed_test;
 
+fn print_completions<G: clap_complete::Generator>(gen: G, cmd: &mut clap::Command) {
+    generate(gen, cmd, cmd.get_name().to_string(), &mut io::stdout());
+}
+
 fn main() {
     env_logger::init();
     let options = SpeedTestCLIOptions::parse();
+
+    if let Some(generator) = options.completion {
+        let mut cmd = SpeedTestCLIOptions::command();
+        eprintln!("Generating completion script for {generator}...");
+        print_completions(generator, &mut cmd);
+        return;
+    }
+
     if options.output_format == OutputFormat::StdOut {
         println!("Starting Cloudflare speed test");
     }