feat(cli): generate autocomplete shell stuff via -c | --completions argument (#37)

curlz/Cargo.toml

@@ -11,7 +11,7 @@ include = ["src/**/*", "LICENSE", "*.md"]
 env_logger = "0.10"
 log = "0.4"
 clap = { version = "4.1", features = ["derive", "std", "cargo", "usage", "help"] }
-#clap_complete = "4.1"
+clap_complete = "4.1"
 clap-verbosity-flag = "2.0"
 serde = { version = "1.0", features = ["derive"] }
 serde_yaml = "0.9"

curlz/src/curlz/cli/execute.rs

@@ -1,19 +1,26 @@
 use super::sub_commands::*;
 
-use clap::Parser;
+use clap::{Command, CommandFactory, Parser};
+use clap_complete::{generate, generator::Generator, Shell};
 use clap_verbosity_flag::{InfoLevel, Verbosity};
 use env_logger::Target;
 
 #[derive(Clone, Debug, Parser)]
 #[command(author, version, about, long_about = None )]
-#[clap(subcommand_required = true, arg_required_else_help = true)]
+#[command(arg_required_else_help = true)]
 #[command(propagate_version = true)]
 #[command(name = "curlz")]
 pub struct Cli {
+    /// increased verbosity will show more debug output of curlz itself
     #[command(flatten)]
     verbose: Verbosity<InfoLevel>,
+
+    /// Generate a SHELL completion script and print to stdout
+    #[clap(long, short, value_name = "SHELL")]
+    pub completions: Option<Shell>,
+
     #[command(subcommand)]
-    pub command: SubCommands,
+    pub cmd: Option<SubCommands>,
 }
 
 pub fn execute() -> crate::Result<()> {
@@ -23,12 +30,26 @@ pub fn execute() -> crate::Result<()> {
         .target(Target::Stderr)
         .init();
 
-    match args.command {
-        SubCommands::Request(ref r) => r.execute(),
-        SubCommands::Bookmark(_b) => {
-            todo!()
+    if let Some(shell) = args.completions {
+        let mut cmd = Cli::command();
+        print_completions(shell, &mut cmd);
+        std::process::exit(0);
+    }
+
+    if let Some(cmd) = &args.cmd {
+        match cmd {
+            SubCommands::Request(ref r) => r.execute(),
+            SubCommands::Bookmark(_b) => {
+                todo!()
+            }
+            #[cfg(feature = "x-http-lang")]
+            SubCommands::HttpFile(ref hf) => hf.execute(),
         }
-        #[cfg(feature = "x-http-lang")]
-        SubCommands::HttpFile(ref hf) => hf.execute(),
+    } else {
+        Ok(())
     }
 }
+
+fn print_completions<G: Generator>(gen: G, cmd: &mut Command) {
+    generate(gen, cmd, cmd.get_name().to_string(), &mut std::io::stdout());
+}

curlz/tests/basics.rs

@@ -9,13 +9,27 @@ mod testlib;
 #[test]
 fn should_show_usage_when_no_args_passed() {
     #[cfg(windows)]
-    let pattern = predicate::str::contains("Usage: curlz.exe [OPTIONS] <COMMAND>");
+    let pattern = predicate::str::contains("Usage: curlz.exe [OPTIONS] [COMMAND]");
     #[cfg(not(windows))]
-    let pattern = predicate::str::contains("Usage: curlz [OPTIONS] <COMMAND>");
+    let pattern = predicate::str::contains("Usage: curlz [OPTIONS] [COMMAND]");
 
     binary().assert().failure().stderr(pattern);
 }
 
+#[test]
+fn should_show_completions() {
+    #[cfg(windows)]
+    let pattern = predicate::str::contains("#compdef curlz");
+    #[cfg(not(windows))]
+    let pattern = predicate::str::contains("#compdef curlz");
+
+    binary()
+        .args(["--completions", "zsh"])
+        .assert()
+        .success()
+        .stdout(pattern);
+}
+
 #[tokio::test]
 async fn should_send_as_get() {
     CurlzTestSuite::new()