More consistent exit handling

vstc/src/assemble_command.rs

@@ -1,12 +1,10 @@
-use std::process::exit;
-
 use valuescript_compiler::{assemble, parse_module};
 
+use crate::exit_command_failed::exit_command_failed;
+
 pub fn assemble_command(args: &Vec<String>) {
   if args.len() != 3 {
-    println!("ERROR: Unrecognized command\n");
-    show_help();
-    exit(1);
+    exit_command_failed(args, None, "vstc assemble --help");
   }
 
   if args[2] == "-h" || args[2] == "--help" {

vstc/src/compile_command.rs

@@ -1,7 +1,7 @@
 use std::fs::File;
 use std::io::Write;
-use std::process::exit;
 
+use crate::exit_command_failed::exit_command_failed;
 use crate::resolve_entry_path::resolve_entry_path;
 
 use super::handle_diagnostics_cli::handle_diagnostics_cli;
@@ -10,9 +10,15 @@ use valuescript_compiler::compile;
 
 pub fn compile_command(args: &Vec<String>) {
   if args.len() != 3 {
-    println!("ERROR: Unrecognized command\n");
-    show_help();
-    exit(1);
+    exit_command_failed(args, None, "vstc compile --help");
+  }
+
+  match args.get(2).map(String::as_str) {
+    Some("--help") | Some("-h") => {
+      show_help();
+      return;
+    }
+    _ => {}
   }
 
   let resolved_entry_path = resolve_entry_path(&args[2]);

vstc/src/db_command.rs

@@ -8,6 +8,7 @@ use valuescript_vm::{
 };
 
 use crate::{
+  exit_command_failed::exit_command_failed,
   handle_diagnostics_cli::handle_diagnostics_cli,
   parse_command_line::parse_command_line,
   to_bytecode::{format_from_path, to_bytecode},
@@ -34,9 +35,7 @@ pub fn db_command(args: &[String]) {
   let path = match args.get(2) {
     Some(path) => path.clone(),
     None => {
-      println!("ERROR: Missing db path\n");
-      show_help();
-      exit(1);
+      exit_command_failed(args, Some("Missing db path"), "vstc db help");
     }
   };
 
@@ -53,9 +52,7 @@ pub fn db_command(args: &[String]) {
         }
       }
 
-      println!("ERROR: Unrecognized db command {:?}\n", args);
-      show_help();
-      exit(1);
+      exit_command_failed(args, None, "vstc db help");
     }
   }
 }
@@ -89,9 +86,7 @@ fn db_new(storage: &mut Storage<SledBackend>, args: &[String]) {
   let class_file = match args.get(0) {
     Some(class_file) => class_file,
     None => {
-      println!("ERROR: Missing class file\n");
-      show_help();
-      exit(1);
+      exit_command_failed(args, Some("Missing class file"), "vstc db help");
     }
   };
 
@@ -136,11 +131,7 @@ fn db_new(storage: &mut Storage<SledBackend>, args: &[String]) {
 fn db_call(storage: &mut Storage<SledBackend>, args: &[String]) {
   let fn_file = match args.get(0) {
     Some(fn_file) => fn_file,
-    None => {
-      println!("ERROR: Missing function file\n");
-      show_help();
-      exit(1);
-    }
+    None => exit_command_failed(args, Some("Missing function file"), "vstc db help"),
   };
 
   let fn_ = Rc::new(to_bytecode(format_from_path(fn_file), fn_file))
@@ -236,7 +227,10 @@ fn db_interactive(storage: &mut Storage<SledBackend>) {
     let args = parse_command_line(&input);
 
     match args.get(0).map(|s| s.as_str()) {
-      // TODO: help (it's a bit different - code isn't quoted (TODO: quoted should work too))
+      Some("help") => {
+        // TODO: help (it's a bit different - code isn't quoted (TODO: quoted should work too))
+        println!("TODO: help");
+      }
       Some("exit" | "quit") => break,
       Some("new") => db_new(storage, args.get(1..).unwrap_or_default()),
       Some("call") => db_call(storage, args.get(1..).unwrap_or_default()),
@@ -245,7 +239,8 @@ fn db_interactive(storage: &mut Storage<SledBackend>) {
           break 'b db_run_inline(storage, &input);
         }
 
-        println!("ERROR: Unrecognized db command {:?}\n", args);
+        println!("Command failed: {:?}", args);
+        println!("  For help: help");
       }
     }
   }

vstc/src/exit_command_failed.rs

@@ -0,0 +1,13 @@
+use std::process::exit;
+
+pub fn exit_command_failed(args: &[String], context: Option<&str>, help: &str) -> ! {
+  println!("Command failed: {:?}", args);
+
+  if let Some(context) = context {
+    println!("  {}", context);
+  }
+
+  println!("  For help: {}", help);
+
+  exit(1);
+}

vstc/src/main.rs

@@ -2,6 +2,7 @@ mod assemble_command;
 mod compile_command;
 mod console_command;
 mod db_command;
+mod exit_command_failed;
 mod handle_diagnostics_cli;
 mod parse_command_line;
 mod resolve_entry_path;
@@ -11,7 +12,6 @@ mod test_inputs;
 mod to_bytecode;
 
 use std::env;
-use std::process::exit;
 
 use assemble_command::assemble_command;
 use compile_command::compile_command;
@@ -20,6 +20,8 @@ use db_command::db_command;
 use run_command::run_command;
 use termion_test::termion_test;
 
+use crate::exit_command_failed::exit_command_failed;
+
 fn main() {
   let args: Vec<String> = env::args().collect();
 
@@ -31,11 +33,7 @@ fn main() {
     Some("db") => db_command(&args),
     Some("termion") => termion_test(),
     Some("console") => console_command(&args),
-    _ => {
-      println!("ERROR: Unrecognized command\n");
-      show_help();
-      exit(1);
-    }
+    _ => exit_command_failed(&args, None, "vstc help"),
   }
 }
 

vstc/src/run_command.rs

@@ -4,13 +4,12 @@ use std::rc::Rc;
 use valuescript_vm::VirtualMachine;
 use valuescript_vm::{vs_value::Val, DecoderMaker};
 
+use crate::exit_command_failed::exit_command_failed;
 use crate::to_bytecode::{format_from_path, to_bytecode, RunFormat};
 
 pub fn run_command(args: &Vec<String>) {
   if args.len() < 3 {
-    println!("ERROR: Unrecognized command\n");
-    show_help();
-    exit(1);
+    exit_command_failed(args, None, "vstc run --help");
   }
 
   let mut argpos = 2;