Add path validation utility and integrate with CLI

Cargo.toml

@@ -1,9 +1,6 @@
 [package]
 name = "pmp"
-description = """\
+description = "PHP Macro Pre-processor (PMP) written in Rust."
-    PHP Macro Pre-processor (PMP) \
-    A php lexer, parser and macro pre-processor written in Rust. \
-"""
 
 version = "0.1.0-alpha"
 edition = "2024"

src/cli/flags.rs

@@ -1,13 +1,18 @@
-use clap::Parser;
 use std::{
     ffi::OsStr,
     path::PathBuf
 };
+use clap::{
+    Parser,
+    ValueHint::FilePath,
+};
+
+use crate::util::fs;
 
 #[derive(Parser, Debug)]
 #[command(name = "pmp", about, version)]
 pub struct Args {
-    #[arg(long)]
+    #[arg(long, value_hint = FilePath, value_parser = fs::path_exists)]
     php: Option<PathBuf>,
 
     #[arg(long, short = 'd', hide = true)]
@@ -15,8 +20,8 @@ pub struct Args {
     #[arg(long, short = 'v')]
     verbose: bool,
 
-    #[arg(default_value_os = OsStr::new("."))]
+    #[arg(default_value_os = OsStr::new("."), value_hint = FilePath, value_parser = fs::path_exists)]
-    files: Vec<PathBuf>,
+    directory: Option<PathBuf>,
     #[arg(last = true)]
     passthrough: Vec<String>,
 }

src/lib.rs

@@ -1 +1,2 @@
 pub mod cli;
+pub mod util;

src/main.rs

@@ -1,8 +1,8 @@
 use pmp::{ cli::Args };
 
-fn main() 
+fn main()
 {
     let args = Args::parse();
 
-    println!("{:?}", args);
+    println!("{:#?}", args);
 }

src/util/fs.rs

@@ -0,0 +1,6 @@
+use std::path::PathBuf;
+
+pub fn path_exists(s: &str) -> Result<PathBuf, String> {
+    let p = PathBuf::from(s);
+    p.exists().then_some(p).ok_or("path does not exist".to_string())
+}

src/util/mod.rs

@@ -0,0 +1 @@
+pub mod fs;