feat(cli): support generating shell completions (#30)

Added a subcommand, `nerdfix completions <SHELL>`, to generate
completions for your shell.

Closes #28

Cargo.toml

@@ -9,7 +9,8 @@ rust-version = "1.75"
 [dependencies]
 bytesize = "1.3"
 camino = "1.1"
-clap = { version = ">=4.0, <4.5", features = ["derive"] }
+clap = { version = "4.5", features = ["derive"] }
+clap_complete = "4.5"
 codespan-reporting = "0.11.1"
 content_inspector = "0.2.4"
 extend = "1.2"

src/cli.rs

@@ -7,18 +7,20 @@ use std::{fmt, fs, io};
 use bytesize::ByteSize;
 use camino::Utf8PathBuf;
 use clap::{Parser, Subcommand, ValueEnum};
+use clap_complete::Shell;
 use shadow_rs::formatcp;
 use thisctx::IntoError;
 
 use crate::icon::Substitution;
 use crate::input::InputReader;
 use crate::{error, shadow};
 
+const V_FORMAT: &str = "FORMAT";
 const V_PATH: &str = "PATH";
+const V_SHELL: &str = "SHELL";
+const V_SIZE: &str = "SIZE";
 const V_SOURCE: &str = "SOURCE";
 const V_SUBSTITUTION: &str = "SUBSTITUTION";
-const V_FORMAT: &str = "FORMAT";
-const V_SIZE: &str = "SIZE";
 const DEFAULT_SIZE: &str = "16MB";
 const INDEX_REV: &str = include_str!("index-rev");
 const CLAP_LONG_VERSION: &str = formatcp!("{}\ncheat-sheet: {}", shadow::PKG_VERSION, INDEX_REV);
@@ -140,6 +142,11 @@ pub enum Command {
     },
     /// Fuzzy search for an icon.
     Search {},
+    /// Generate shell completions for your shell to stdout.
+    Completions {
+        #[arg(value_name = V_SHELL)]
+        shell: Shell,
+    },
 }
 
 #[derive(Clone, Debug)]

src/main.rs

@@ -195,6 +195,14 @@ fn main_impl() -> error::Result<()> {
         Command::Search {} => {
             rt.build().prompt_input_icon(None).ok();
         }
+        Command::Completions { shell } => {
+            clap_complete::generate(
+                shell,
+                &mut <cli::Cli as clap::CommandFactory>::command(),
+                shadow::PROJECT_NAME,
+                &mut std::io::stdout(),
+            );
+        }
     }
     Ok(())
 }