refactor(complete): Add a subcommand to examples

It's useful when testing to have a subcommand in the examples.

clap_complete/examples/completion-derive.rs

@@ -12,7 +12,7 @@
 //! . ./value_hints_derive.fish
 //! ./target/debug/examples/value_hints_derive --<TAB>
 //! ```
-use clap::{Command, CommandFactory, Parser, ValueHint};
+use clap::{Args, Command, CommandFactory, Parser, Subcommand, ValueHint};
 use clap_complete::{generate, Generator, Shell};
 use std::ffi::OsString;
 use std::io;
@@ -24,6 +24,17 @@ struct Opt {
     // If provided, outputs the completion file for given shell
     #[arg(long = "generate", value_enum)]
     generator: Option<Shell>,
+    #[clap(subcommand)]
+    command: Option<Commands>,
+}
+
+#[derive(Subcommand, Debug, PartialEq)]
+enum Commands {
+    ValueHint(ValueHintOpt),
+}
+
+#[derive(Args, Debug, PartialEq)]
+struct ValueHintOpt {
     // Showcasing all possible ValueHints:
     #[arg(long, value_hint = ValueHint::Unknown)]
     unknown: Option<String>,

clap_complete/examples/completion.rs

@@ -17,12 +17,7 @@ use clap_complete::{generate, Generator, Shell};
 use std::io;
 
 fn build_cli() -> Command {
-    Command::new("completion")
-        .arg(
-            Arg::new("generator")
-                .long("generate")
-                .value_parser(value_parser!(Shell)),
-        )
+    let value_hint_command = Command::new("value-hint")
         .arg(
             Arg::new("unknown")
                 .long("unknown")
@@ -87,7 +82,15 @@ fn build_cli() -> Command {
             Arg::new("email")
                 .long("email")
                 .value_hint(ValueHint::EmailAddress),
+        );
+
+    Command::new("completion")
+        .arg(
+            Arg::new("generator")
+                .long("generate")
+                .value_parser(value_parser!(Shell)),
         )
+        .subcommand(value_hint_command)
 }
 
 fn print_completions<G: Generator>(gen: G, cmd: &mut Command) {