CLI help & empty commands

src/cli/empty.rs

@@ -0,0 +1,46 @@
+use crate::cli::{get_help_text, get_version};
+use colored::*;
+
+#[derive(Eq, PartialEq, Hash)]
+enum EmptyOptions {
+    Help,
+    Version,
+}
+
+pub fn empty_command(options: &Vec<String>) {
+    // Add all options to a set
+    let mut options_set = std::collections::HashSet::new();
+    for option in options {
+        match expand_option(option) {
+            Ok(o) => {
+                options_set.insert(o);
+            }
+            Err(invalid_option) => {
+                println!("{}", get_help_text());
+                println!("{}: invalid option: `{}`", "error".on_red(), invalid_option);
+                return;
+            }
+        };
+    }
+    let options = options_set;
+
+    if options.is_empty() {
+        println!("{}", get_help_text());
+    } else {
+        if options.contains(&EmptyOptions::Version) {
+            println!("{}\n", get_version());
+        }
+
+        if options.contains(&EmptyOptions::Help) {
+            println!("{}", get_help_text());
+        }
+    }
+}
+
+fn expand_option(option: &String) -> Result<EmptyOptions, String> {
+    match option.as_str() {
+        "-h" | "--help" => Ok(EmptyOptions::Help),
+        "-v" | "--version" => Ok(EmptyOptions::Version),
+        _ => Err(option.clone()),
+    }
+}

src/cli/help.rs

@@ -5,6 +5,10 @@ pub fn help_command(options: &Vec<String>) {
     println!("{}", get_help_text());
 
     if options.len() > 0 {
-        println!("{}: {}", "warning".yellow(), "The help command doesn't take any options.");
+        println!(
+            "{}: {}",
+            "warning".yellow(),
+            "The help command doesn't take any options."
+        );
     }
 }

src/cli/mod.rs

@@ -1,6 +1,6 @@
+mod empty;
 mod help;
 mod types;
-mod empty;
 
 use types::{Command, CommandType};
 
@@ -27,6 +27,7 @@ Commands
 General options
 
   -h, --help    Print command-specific usage
+  -v, --version Print version & exit
 "#,
         "_file_".green()
     )
@@ -55,18 +56,25 @@ fn parse_args() -> Result<Command, String> {
     args.remove(0);
 
     let mut args = args.into_iter();
+    let mut options = Vec::new();
 
     let command = match args.next() {
         Some(command) if !command.starts_with('-') => Some(command),
+        Some(option) => {
+            options.push(option);
+            None
+        }
         _ => None,
     };
 
-    let mut options = Vec::new();
     for arg in args {
         if arg.starts_with('-') {
             options.push(arg);
         } else {
-            return Err(format!("Unexpected command `{}` after the options", arg));
+            return Err(format!(
+                "Unexpected command `{}`. There can only be one command",
+                arg
+            ));
         }
     }
 

src/cli/types.rs

@@ -27,6 +27,7 @@ impl CommandType {
     pub fn run(&self, options: &Vec<String>) {
         match self {
             CommandType::Help => super::help::help_command(options),
+            CommandType::None => super::empty::empty_command(options),
             _ => {
                 println!("Not implemented yet! {:?} {:?}", self, options);
             }