Main: Rewrite arguments parsing using clap

src/main.rs

@@ -1,21 +1,35 @@
 use std::env;
 use std::fs;
+use std::path::PathBuf;
 
 use anyhow::Result;
 
+use clap::Parser;
 use serde_json::{Map, Value};
 use url_escape;
 
 use handlebars::{Context, Handlebars, Helper, HelperResult, JsonRender, Output, RenderContext, RenderErrorReason};
 
+#[derive(clap::Parser)]
+#[command(author, version, about, long_about = None)]
+struct Arguments {
+    /// The path to the contents file
+    contents_path: PathBuf,
+
+    /// The path to write the built secret file to
+    output_path: PathBuf,
+}
+
 fn main() -> Result<()> {
+    let Arguments {
+        contents_path,
+        output_path,
+    } = Arguments::parse();
+
     let mut handlebars = Handlebars::new();
 
-    let path_to_contents = env::args().nth(1).expect("The first argument to be present.");
+    let contents = fs::read_to_string(&contents_path)
-    let output_path = env::args().nth(2).expect("The second argument to be present.");
+        .expect(format!("To be able to read the contents file at the path '{}' passed as the first argument.", contents_path.to_string_lossy()).as_str());
-
-    let contents = fs::read_to_string(&path_to_contents)
-        .expect(format!("To be able to read the contents file at the path '{path_to_contents}' passed as the first argument.").as_str());
 
     let secret_inputs = env::vars().filter(|(key, _)| key.starts_with("SECRET_"));
 
@@ -75,7 +89,7 @@ fn main() -> Result<()> {
     let output = handlebars.render_template(contents.as_str(), &Value::Object(data_map))?;
 
     fs::write(&output_path, output)
-        .expect(format!("To be able to write to {output_path}").as_str());
+        .expect(format!("To be able to write to '{}'", output_path.to_string_lossy()).as_str());
 
     Ok(())
 }