Implement relative path requires, proper exit codes

.lune/hello_lune.luau

@@ -6,7 +6,7 @@ print("Hello, lune! 🌙")
 	Using a function from another module
 ]==]
 
-local module = require(".lune/module")
+local module = require("./module")
 module.sayHello()
 
 --[==[
@@ -36,8 +36,7 @@ end)
 
 print("Spawning a delayed task that will run in 5 seconds")
 task.delay(5, function()
-	print()
+	print("\n...")
-	print("...")
 	task.wait(1)
 	print("Hello again!")
 	task.wait(1)

CHANGELOG.md

@@ -5,6 +5,18 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## Unreleased
+
+### Changed
+
+- `require` now uses paths relative to the file instead of being relative to the current directory, which is consistent with almost all other languages but not original Lua / Luau - this is a breaking change but will allow for proper packaging of third-party modules and more in the future.
+- Improved error message when an invalid file path is passed to `require`
+- Much improved error formatting and stack traces
+
+### Fixed
+
+- Process termination will now always make sure all lua state is cleaned up before exiting, in all cases
+
 ## `0.0.6` - January 23rd, 2023
 
 ### Added

src/cli/cli.rs

@@ -1,4 +1,4 @@
-use std::fs::read_to_string;
+use std::{fs::read_to_string, process::ExitCode};
 
 use anyhow::Result;
 use clap::{CommandFactory, Parser};
@@ -54,7 +54,7 @@ impl Cli {
         }
     }
 
-    pub async fn run(self) -> Result<()> {
+    pub async fn run(self) -> Result<ExitCode> {
         // Download definition files, if wanted
         let download_types_requested = self.download_selene_types || self.download_luau_types;
         if download_types_requested {
@@ -82,7 +82,7 @@ impl Cli {
             // Only downloading types without running a script is completely
             // fine, and we should just exit the program normally afterwards
             if download_types_requested {
-                return Ok(());
+                return Ok(ExitCode::SUCCESS);
             }
             // HACK: We know that we didn't get any arguments here but since
             // script_path is optional clap will not error on its own, to fix
@@ -98,10 +98,13 @@ impl Cli {
         let file_display_name = file_path.with_extension("").display().to_string();
         // Create a new lune object with all globals & run the script
         let lune = Lune::new().with_args(self.script_args).with_all_globals();
-        if let Err(e) = lune.run(&file_display_name, &file_contents).await {
+        let result = lune.run(&file_display_name, &file_contents).await;
+        Ok(match result {
+            Err(e) => {
                 eprintln!("{e}");
-            std::process::exit(1);
+                ExitCode::from(1)
-        };
+            }
-        Ok(())
+            Ok(code) => code,
+        })
     }
 }

src/cli/main.rs

@@ -2,6 +2,8 @@
 #![warn(clippy::cargo, clippy::pedantic)]
 #![allow(clippy::needless_pass_by_value, clippy::match_bool)]
 
+use std::process::ExitCode;
+
 use anyhow::Result;
 use clap::Parser;
 
@@ -10,10 +12,6 @@ mod utils;
 
 use cli::Cli;
 
-fn main() -> Result<()> {
+fn main() -> Result<ExitCode> {
-    smol::block_on(async {
+    smol::block_on(async { Cli::parse().run().await })
-        let cli = Cli::parse();
-        cli.run().await?;
-        Ok(())
-    })
 }

src/lib/globals/mod.rs

@@ -2,10 +2,12 @@ mod console;
 mod fs;
 mod net;
 mod process;
+mod require;
 mod task;
 
 pub use console::create as create_console;
 pub use fs::create as create_fs;
 pub use net::create as create_net;
 pub use process::create as create_process;
+pub use require::create as create_require;
 pub use task::create as create_task;

src/lib/globals/require.rs

@@ -0,0 +1,72 @@
+use std::{env, path::PathBuf, sync::Arc};
+
+use mlua::prelude::*;
+use os_str_bytes::RawOsStr;
+
+pub fn create(lua: &Lua) -> LuaResult<()> {
+    // Preserve original require behavior if we have a special env var set
+    if env::var_os("LUAU_PWD_REQUIRE").is_some() {
+        return Ok(());
+    }
+    // Fetch the debug info function and store it in the registry
+    // - we will use it to fetch the current scripts file name
+    let debug: LuaTable = lua.globals().raw_get("debug")?;
+    let info: LuaFunction = debug.raw_get("info")?;
+    lua.set_named_registry_value("require_getinfo", info)?;
+    // Fetch the original require function and store it in the registry
+    let require: LuaFunction = lua.globals().raw_get("require")?;
+    lua.set_named_registry_value("require_original", require)?;
+    /*
+      Create a new function that fetches the file name from the current thread,
+      sets the luau module lookup path to be the exact script we are looking
+      for, and then runs the original require function with the wanted path
+    */
+    let new_require = lua.create_function(|lua, require_path: LuaString| {
+        let require_original: LuaFunction = lua.named_registry_value("require_original")?;
+        let require_getinfo: LuaFunction = lua.named_registry_value("require_getinfo")?;
+        let require_source: LuaString = require_getinfo.call((2, "s"))?;
+        /*
+          Combine the require caller source with the wanted path
+          string to get a final path relative to pwd - it is definitely
+          relative to pwd because Lune will only load files relative to pwd
+
+          Here we also take extra care to not perform any lossy conversion
+          and use os strings instead of Rust's utf-8 checked strings, in the
+          unlikely case someone out there uses luau with non-utf8 string requires
+        */
+        let raw_source = RawOsStr::assert_from_raw_bytes(require_source.as_bytes());
+        let raw_path = RawOsStr::assert_from_raw_bytes(require_path.as_bytes());
+        let path_relative_to_pwd = PathBuf::from(&raw_source.to_os_str())
+            .parent()
+            .unwrap()
+            .join(raw_path.to_os_str());
+        // Create a lossless lua string from the pathbuf and finally call require
+        let raw_path_str = RawOsStr::new(path_relative_to_pwd.as_os_str());
+        let lua_path_str = lua.create_string(raw_path_str.as_raw_bytes());
+        // If the require call errors then we should also replace
+        // the path in the error message to improve user experience
+        let result: LuaResult<_> = require_original.call::<_, LuaValue>(lua_path_str);
+        match result {
+            Err(LuaError::CallbackError { traceback, cause }) => {
+                let before = format!(
+                    "runtime error: cannot find '{}'",
+                    path_relative_to_pwd.to_str().unwrap()
+                );
+                let after = format!(
+                    "Invalid require path '{}' ({})",
+                    require_path.to_str().unwrap(),
+                    path_relative_to_pwd.to_str().unwrap()
+                );
+                let cause = Arc::new(LuaError::RuntimeError(
+                    cause.to_string().replace(&before, &after),
+                ));
+                Err(LuaError::CallbackError { traceback, cause })
+            }
+            Err(e) => Err(e),
+            Ok(result) => Ok(result),
+        }
+    })?;
+    // Override the original require global with our monkey-patched one
+    lua.globals().raw_set("require", new_require)?;
+    Ok(())
+}

src/lib/lib.rs

@@ -1,4 +1,4 @@
-use std::{collections::HashSet, sync::Arc};
+use std::{collections::HashSet, process::ExitCode, sync::Arc};
 
 use anyhow::{anyhow, bail, Result};
 use mlua::prelude::*;
@@ -8,7 +8,7 @@ pub mod globals;
 pub mod utils;
 
 use crate::{
-    globals::{create_console, create_fs, create_net, create_process, create_task},
+    globals::{create_console, create_fs, create_net, create_process, create_require, create_task},
     utils::formatting::pretty_format_luau_error,
 };
 
@@ -21,6 +21,7 @@ pub enum LuneGlobal {
     Fs,
     Net,
     Process,
+    Require,
     Task,
 }
 
@@ -31,6 +32,7 @@ impl LuneGlobal {
             Self::Fs,
             Self::Net,
             Self::Process,
+            Self::Require,
             Self::Task,
         ]
     }
@@ -73,7 +75,7 @@ impl Lune {
         self
     }
 
-    pub async fn run(&self, name: &str, chunk: &str) -> Result<u8> {
+    pub async fn run(&self, name: &str, chunk: &str) -> Result<ExitCode> {
         let (s, r) = smol::channel::unbounded::<LuneMessage>();
         let lua = Arc::new(mlua::Lua::new());
         let exec = Arc::new(LocalExecutor::new());
@@ -90,6 +92,7 @@ impl Lune {
                 LuneGlobal::Fs => create_fs(&lua)?,
                 LuneGlobal::Net => create_net(&lua)?,
                 LuneGlobal::Process => create_process(&lua, self.args.clone())?,
+                LuneGlobal::Require => create_require(&lua)?,
                 LuneGlobal::Task => create_task(&lua)?,
             }
         }
@@ -100,7 +103,7 @@ impl Lune {
             sender.send(LuneMessage::Spawned).await?;
             let result = lua
                 .load(&script_chunk)
-                .set_name(&script_name)
+                .set_name(&format!("={}", script_name))
                 .unwrap()
                 .call_async::<_, LuaMultiValue>(LuaMultiValue::new())
                 .await;
@@ -155,7 +158,7 @@ impl Lune {
                         task_count += 1;
                     }
                     LuneMessage::LuaError(e) => {
-                        eprintln!("{}", e);
+                        eprintln!("{}", pretty_format_luau_error(&e));
                         got_error = true;
                         task_count += 1;
                     }
@@ -171,11 +174,11 @@ impl Lune {
         // If we got an error, we will default to exiting
         // with code 1, unless a code was manually given
         if got_code {
-            Ok(exit_code)
+            Ok(ExitCode::from(exit_code))
         } else if got_error {
-            Ok(1)
+            Ok(ExitCode::FAILURE)
         } else {
-            Ok(0)
+            Ok(ExitCode::SUCCESS)
         }
     }
 }
@@ -183,9 +186,9 @@ impl Lune {
 #[cfg(test)]
 mod tests {
     use crate::Lune;
-    use anyhow::{bail, Result};
+    use anyhow::Result;
     use smol::fs::read_to_string;
-    use std::env::current_dir;
+    use std::process::ExitCode;
 
     const ARGS: &[&str] = &["Foo", "Bar"];
 
@@ -193,12 +196,10 @@ mod tests {
         ($($name:ident: $value:expr,)*) => {
             $(
                 #[test]
-                fn $name() -> Result<()> {
+                fn $name() -> Result<ExitCode> {
                     smol::block_on(async {
-                        let path = current_dir()
+                        let full_name = format!("src/tests/{}.luau", $value);
-                            .unwrap()
+                        let script = read_to_string(&full_name)
-                            .join(format!("src/tests/{}.luau", $value));
-                        let script = read_to_string(&path)
                             .await
                             .unwrap();
                         let lune = Lune::new()
@@ -210,11 +211,8 @@ mod tests {
                                     .collect()
                             )
                             .with_all_globals();
-                        let exit_code = lune.run($value, &script).await?;
+                        let script_name = full_name.strip_suffix(".luau").unwrap();
-                        if exit_code != 0 {
+                        lune.run(&script_name, &script).await
-                            bail!("Test exited with failure code {}", exit_code);
-                        }
-                        Ok(())
                     })
                 }
             )*
@@ -227,15 +225,20 @@ mod tests {
         console_set_style: "console/set_style",
         fs_files: "fs/files",
         fs_dirs: "fs/dirs",
-        process_args: "process/args",
-        process_env: "process/env",
-        process_exit: "process/exit",
-        process_spawn: "process/spawn",
         net_request_codes: "net/request/codes",
         net_request_methods: "net/request/methods",
         net_request_redirect: "net/request/redirect",
         net_json_decode: "net/json/decode",
         net_json_encode: "net/json/encode",
+        process_args: "process/args",
+        process_env: "process/env",
+        process_exit: "process/exit",
+        process_spawn: "process/spawn",
+        require_children: "require/tests/children",
+        require_invalid: "require/tests/invalid",
+        require_nested: "require/tests/nested",
+        require_parents: "require/tests/parents",
+        require_siblings: "require/tests/siblings",
         task_cancel: "task/cancel",
         task_defer: "task/defer",
         task_delay: "task/delay",

src/lib/utils/formatting.rs

@@ -204,23 +204,36 @@ pub fn pretty_format_luau_error(e: &LuaError) -> String {
                 .lines()
                 .map(|s| s.to_string())
                 .collect::<Vec<String>>();
+            let mut found_stack_begin = false;
             for (index, line) in err_lines.clone().iter().enumerate().rev() {
                 if *line == "stack traceback:" {
                     err_lines[index] = stack_begin;
+                    found_stack_begin = true;
                     break;
                 }
             }
             // Add "Stack End" to the very end of the stack trace for symmetry
+            if found_stack_begin {
                 err_lines.push(stack_end);
+            }
             err_lines.join("\n")
         }
-        LuaError::CallbackError { cause, traceback } => {
+        LuaError::CallbackError { traceback, cause } => {
+            // Find the best traceback (longest) and the root error message
+            let mut best_trace = traceback;
+            let mut root_cause = cause.as_ref();
+            while let LuaError::CallbackError { cause, traceback } = root_cause {
+                if traceback.len() > best_trace.len() {
+                    best_trace = traceback;
+                }
+                root_cause = cause;
+            }
             // Same error formatting as above
             format!(
-                "{}\n{}{}{}",
+                "{}\n{}\n{}\n{}",
-                pretty_format_luau_error(cause.as_ref()),
+                pretty_format_luau_error(root_cause),
                 stack_begin,
-                traceback.strip_prefix("stack traceback:\n").unwrap(),
+                best_trace.strip_prefix("stack traceback:\n").unwrap(),
                 stack_end
             )
         }
@@ -247,6 +260,8 @@ pub fn pretty_format_luau_error(e: &LuaError) -> String {
     let mut err_lines = err_string.lines().collect::<Vec<_>>();
     // Remove the script path from the error message
     // itself, it can be found in the stack trace
+    // FIXME: This no longer works now that we use
+    // an exact name when our lune script is loaded
     if let Some(first_line) = err_lines.first() {
         if first_line.starts_with("[string \"") {
             if let Some(closing_bracket) = first_line.find("]:") {
@@ -260,7 +275,6 @@ pub fn pretty_format_luau_error(e: &LuaError) -> String {
             }
         }
     }
-    // Reformat stack trace lines, ignore lines that just mention C functions
     // Merge all lines back together into one string
     err_lines.join("\n")
 }

src/tests/net/request/codes.luau

@@ -1,4 +1,4 @@
-local util = require("src/tests/net/request/util")
+local util = require("./util")
 local pass, fail = util.pass, util.fail
 
 pass("GET", "https://httpbin.org/status/200", "Request status code - 200")

src/tests/net/request/methods.luau

@@ -1,4 +1,4 @@
-local util = require("src/tests/net/request/util")
+local util = require("./util")
 local pass = util.pass
 
 -- stylua: ignore start

src/tests/net/request/redirect.luau

@@ -1,4 +1,4 @@
-local util = require("src/tests/net/request/util")
+local util = require("./util")
 local pass = util.pass
 
 pass("GET", "https://httpbin.org/absolute-redirect/3", "Redirect 3 times")

src/tests/require/modules/module.luau

@@ -0,0 +1,4 @@
+return {
+	Foo = "Bar",
+	Hello = "World",
+}

src/tests/require/tests/children.luau

@@ -0,0 +1,7 @@
+local module = require("./modules/module")
+
+assert(type(module) == "table", "Required module did not return a table")
+assert(module.Foo == "Bar", "Required module did not contain correct values")
+assert(module.Hello == "World", "Required module did not contain correct values")
+
+require("modules/module")

src/tests/require/tests/invalid.luau

@@ -0,0 +1,26 @@
+local function test(path: string)
+	local success, message = pcall(function()
+		local _ = require(path) :: any
+	end)
+	if success then
+		error(string.format("Invalid require at path '%s' succeeded", path))
+	else
+		message = tostring(message)
+		if string.find(message, string.format("'%s'", path)) == nil then
+			error(
+				string.format(
+					"Invalid require did not mention path '%s' in its error message!\nMessage: %s",
+					path,
+					tostring(message)
+				)
+			)
+		end
+	end
+end
+
+test("foo")
+test("bar")
+test("moduuuuule")
+test("modules.nested")
+test(" modules ")
+test("mod" .. string.char(127) .. "ules")

src/tests/require/tests/module.luau

@@ -0,0 +1,4 @@
+return {
+	Foo = "Bar",
+	Hello = "World",
+}

src/tests/require/tests/modules/module.luau

@@ -0,0 +1,4 @@
+return {
+	Foo = "Bar",
+	Hello = "World",
+}

src/tests/require/tests/modules/modules/module.luau

@@ -0,0 +1,4 @@
+return {
+	Foo = "Bar",
+	Hello = "World",
+}

src/tests/require/tests/modules/nested.luau

@@ -0,0 +1 @@
+return require("modules/module")

src/tests/require/tests/nested.luau

@@ -0,0 +1,7 @@
+local module = require("./modules/nested")
+
+assert(type(module) == "table", "Required module did not return a table")
+assert(module.Foo == "Bar", "Required module did not contain correct values")
+assert(module.Hello == "World", "Required module did not contain correct values")
+
+require("modules/nested")

src/tests/require/tests/parents.luau

@@ -0,0 +1,5 @@
+local module = require("../modules/module")
+
+assert(type(module) == "table", "Required module did not return a table")
+assert(module.Foo == "Bar", "Required module did not contain correct values")
+assert(module.Hello == "World", "Required module did not contain correct values")

src/tests/require/tests/siblings.luau

@@ -0,0 +1,11 @@
+local module = require("./module")
+
+assert(type(module) == "table", "Required module did not return a table")
+assert(module.Foo == "Bar", "Required module did not contain correct values")
+assert(module.Hello == "World", "Required module did not contain correct values")
+
+require("./children")
+require("./parents")
+
+require("children")
+require("parents")