Update clap dependency to 4.0

Update the clap dependency to 4.0 to get the latest that there is in
terms of argument handling.

TODO:
> ---- tests::otp::set_get_totp_storage stdout ----
> Error: error: invalid value '8' for '--digits <DIGITS>'
>   [possible values: six-digits, eight-digits]
>
> For more information, try '--help'.
>
>
> ---- tests::otp::set_stdin_storage stdout ----
> Error: error: invalid value '8' for '--digits <DIGITS>'
>   [possible values: six-digits, eight-digits]
>
> For more information, try '--help'.

Author: d-e-s-o

CHANGELOG.md

@@ -8,7 +8,7 @@ Unreleased
 - Added community maintained Nix flake to the repository
 - Adjusted program to use Rust Edition 2021
 - Updated minimum supported Rust version to `1.56.0`
-- Updated argument handling to use `clap` `3.0`
+- Updated argument handling to use `clap` `4.0`
 - Bumped `anyhow` dependency to `1.0.89`
 - Bumped `base32` dependency to `0.5.1`
 - Bumped `directories` dependency to `5.0.1`

Cargo.lock

@@ -1,6 +1,6 @@
 # Cargo.toml
 
-# Copyright (C) 2017-2024 The Nitrocli Developers
+# Copyright (C) 2017-2025 The Nitrocli Developers
 # SPDX-License-Identifier: GPL-3.0-or-later
 
 [package]
@@ -47,12 +47,12 @@ version = "1.0"
 version = "0.5.1"
 
 [dependencies.clap]
-version = "3.0"
+version = "4.0"
 default-features = false
-features = ["derive", "std", "unicode"]
+features = ["derive", "error-context", "help", "std", "string", "unicode", "usage"]
 
 [dependencies.clap_complete]
-version = "3.0"
+version = "4.0"
 optional = true
 
 [dependencies.directories]

Cargo.toml

@@ -1,14 +1,14 @@
 // otp_cache.rs
 
-// Copyright (C) 2020-2024 The Nitrocli Developers
+// Copyright (C) 2020-2025 The Nitrocli Developers
 // SPDX-License-Identifier: GPL-3.0-or-later
 
 use std::fs;
 use std::io::Write as _;
 use std::path;
 
 use anyhow::Context as _;
-use clap::StructOpt as _;
+use clap::Parser as _;
 
 mod ext;
 
@@ -33,17 +33,17 @@ struct Slot {
 /// `--force-update` option is set. The cache includes the Nitrokey's
 /// serial number so that it is possible to use it with multiple
 /// devices.
-#[derive(Debug, clap::StructOpt)]
-#[structopt(bin_name = "nitrocli otp-cache")]
+#[derive(Debug, clap::Parser)]
+#[clap(bin_name = "nitrocli otp-cache")]
 struct Args {
   /// Always query the slot data even if it is already cached
-  #[structopt(short, long, global = true)]
+  #[clap(short, long, global = true)]
   force_update: bool,
-  #[structopt(subcommand)]
+  #[clap(subcommand)]
   cmd: Command,
 }
 
-#[derive(Debug, clap::StructOpt)]
+#[derive(Debug, clap::Parser)]
 enum Command {
   /// Generates a one-time password
   Get {
@@ -55,12 +55,12 @@ enum Command {
 }
 
 fn main() -> anyhow::Result<()> {
-  let args = Args::from_args();
+  let args = Args::parse();
   let ctx = ext::Context::from_env()?;
 
   let cache = get_cache(&ctx, args.force_update)?;
   match &args.cmd {
-    Command::Get { name } => cmd_get(&ctx, &cache, name)?,
+    Command::Get { name } => cmd_get(&ctx, &cache, &name)?,
     Command::List => cmd_list(&cache),
   }
   Ok(())

ext/otp_cache.rs

@@ -1,6 +1,6 @@
 // arg_util.rs
 
-// Copyright (C) 2019-2024 The Nitrocli Developers
+// Copyright (C) 2019-2025 The Nitrocli Developers
 // SPDX-License-Identifier: GPL-3.0-or-later
 
 macro_rules! count {
@@ -22,7 +22,7 @@ macro_rules! Command {
     $( $(#[$doc:meta])* $var:ident$(($inner:ty))? => $exec:expr, ) *
   ] ) => {
     $(#[$docs])*
-    #[derive(Debug, PartialEq, clap::StructOpt)]
+    #[derive(Debug, PartialEq, clap::Parser)]
     pub enum $name {
       $(
         $(#[$doc])*
@@ -53,7 +53,7 @@ macro_rules! Command {
 macro_rules! Enum {
   ( $(#[$docs:meta])* $name:ident, [ $( $var:ident => $str:expr, ) *] ) => {
     $(#[$docs])*
-    #[derive(Clone, Copy, Debug, Eq, Ord, PartialEq, PartialOrd)]
+    #[derive(Clone, Copy, Debug, Eq, Ord, PartialEq, PartialOrd, clap::ValueEnum)]
     pub enum $name {
       $(
         $var,