lux_lib/operations/
run_lua.rs

1//! Run the `lua` binary with some given arguments.
2//!
3//! The interfaces exposed here ensure that the correct version of Lua is being used.
4
5use bon::Builder;
6
7use crate::{
8    config::Config,
9    lua_installation::{LuaInstallation, LuaInstallationError},
10    lua_version::LuaVersion,
11    tree::InstallTree,
12};
13
14use std::{
15    io,
16    path::{Path, PathBuf},
17    process::Stdio,
18};
19
20use miette::Diagnostic;
21use thiserror::Error;
22use tokio::process::Command;
23
24use crate::{
25    lua_installation::{LuaBinary, LuaBinaryError},
26    path::{LuaEnvironment, Paths, PathsError},
27    tree::Tree,
28    tree::TreeError,
29};
30
31#[derive(Error, Debug, Diagnostic)]
32pub enum RunLuaError {
33    #[error("error running lua")]
34    #[diagnostic(forward(0))]
35    LuaBinary(#[from] LuaBinaryError),
36    #[error("failed to detect or install the lua runtime")]
37    #[diagnostic(forward(0))]
38    LuaInstallation(#[from] LuaInstallationError),
39    #[error("failed to run {lua_cmd}: {source}")]
40    LuaCommandFailed {
41        lua_cmd: String,
42        #[source]
43        source: io::Error,
44    },
45    #[error("{lua_cmd} exited with non-zero exit code: {}", exit_code.map(|code| code.to_string()).unwrap_or("unknown".into()))]
46    LuaCommandNonZeroExitCode {
47        lua_cmd: String,
48        exit_code: Option<i32>,
49    },
50    #[error(transparent)]
51    #[diagnostic(transparent)]
52    Paths(#[from] PathsError),
53
54    #[error(transparent)]
55    #[diagnostic(transparent)]
56    Tree(#[from] TreeError),
57}
58
59#[derive(Builder)]
60#[builder(start_fn = new, finish_fn(name = _build, vis = ""))]
61pub struct RunLua<'a> {
62    root: &'a Path,
63    tree: &'a Tree,
64    config: &'a Config,
65    lua_cmd: LuaBinary,
66    args: &'a Vec<String>,
67    prepend_test_paths: Option<bool>,
68    prepend_build_paths: Option<bool>,
69    disable_loader: Option<bool>,
70    lua_init: Option<String>,
71    welcome_message: Option<String>,
72    environment: LuaEnvironment,
73}
74
75impl<State> RunLuaBuilder<'_, State>
76where
77    State: run_lua_builder::State + run_lua_builder::IsComplete,
78{
79    pub async fn run_lua(self) -> Result<(), RunLuaError> {
80        let args = self._build();
81        let mut paths = Paths::for_environment(args.tree, args.config, args.environment)?;
82
83        if args.prepend_test_paths.unwrap_or(false) {
84            let test_tree_path = args.tree.test_tree(args.config)?;
85
86            let test_path = Paths::new(&test_tree_path)?;
87
88            paths.prepend(&test_path);
89        }
90
91        if args.prepend_build_paths.unwrap_or(false) {
92            let build_tree_path = args.tree.build_tree(args.config)?;
93
94            let build_path = Paths::new(&build_tree_path)?;
95
96            paths.prepend(&build_path);
97        }
98
99        let lua_cmd: PathBuf = args.lua_cmd.try_into()?;
100
101        let loader_init = if args.tree.version().is_luau() || args.disable_loader.unwrap_or(false) {
102            "".to_string()
103        } else {
104            let is_lux_lua_available = detect_lux_lua(&lua_cmd, &paths, args.environment).await;
105            if !is_lux_lua_available && args.tree.version().lux_lib_dir().is_none() {
106                tracing::warn!("lux-lua library not found.\nCannot use the `lux.loader`.\nTo suppress this warning, set the `--no-loader` option.");
107                "".to_string()
108            } else {
109                paths.init()
110            }
111        };
112        let lua_init = format!(
113            r#"print([==[{}]==])
114{}
115{}
116        "#,
117            args.welcome_message.unwrap_or_default(),
118            args.lua_init.unwrap_or_default(),
119            loader_init
120        );
121
122        let status = match Command::new(&lua_cmd)
123            .current_dir(args.root)
124            .args(args.args)
125            .env("PATH", paths.path_prepended().joined())
126            .envs(paths.lua_env_vars(args.environment, &lua_init))
127            .status()
128            .await
129        {
130            Ok(status) => Ok(status),
131            Err(err) => Err(RunLuaError::LuaCommandFailed {
132                lua_cmd: lua_cmd.to_string_lossy().to_string(),
133                source: err,
134            }),
135        }?;
136        if status.success() {
137            Ok(())
138        } else {
139            Err(RunLuaError::LuaCommandNonZeroExitCode {
140                lua_cmd: lua_cmd.to_string_lossy().to_string(),
141                exit_code: status.code(),
142            })
143        }
144    }
145}
146
147/// Attempts to detect lux-lua by invoking a Lua command
148/// in case it's a Lua wrapper, like the one created
149/// in nixpkgs using `lua.withPackages (ps: [ps.lux-lua])`.
150/// If the command fails for any reason (including not being able to find the 'lux' module),
151/// this function evaluates to `false`.
152async fn detect_lux_lua(lua_cmd: &Path, paths: &Paths, environment: LuaEnvironment) -> bool {
153    detect_lua_module(lua_cmd, "lux", paths, environment).await
154}
155
156async fn detect_lua_module(
157    lua_cmd: &Path,
158    module: &str,
159    paths: &Paths,
160    environment: LuaEnvironment,
161) -> bool {
162    Command::new(lua_cmd)
163        .arg("-e")
164        .arg(format!(
165            "if pcall(require, '{}') then os.exit(0) else os.exit(1) end",
166            module
167        ))
168        .stderr(Stdio::null())
169        .stdout(Stdio::null())
170        .envs(paths.lua_env_vars(environment, ""))
171        .env("PATH", paths.path_prepended().joined())
172        .status()
173        .await
174        .is_ok_and(|status| status.success())
175}
176
177/// Resolves the interpreter binary for the given Lua version.
178///
179/// Falls back to probing, reusing or building a toolchain via
180/// `LuaInstallation` when no suitable binary is found on the PATH.
181pub(crate) async fn resolve_lua_runtime(
182    version: &LuaVersion,
183    config: &Config,
184) -> Result<PathBuf, RunLuaError> {
185    match <LuaBinary as TryInto<PathBuf>>::try_into(LuaBinary::new(version.clone(), config)) {
186        Ok(lua_cmd) => Ok(lua_cmd),
187        Err(err) => {
188            let lua_installation = LuaInstallation::new(version, config).await?;
189            lua_installation
190                .bin()
191                .clone()
192                .ok_or(RunLuaError::LuaBinary(err))
193        }
194    }
195}
196
197#[cfg(test)]
198mod tests {
199    use std::str::FromStr;
200
201    use super::*;
202    use crate::fs;
203    use crate::path::PackagePath;
204    use assert_fs::prelude::{PathChild, PathCreateDir};
205    use assert_fs::TempDir;
206    use path_slash::PathBufExt;
207    use which::which;
208
209    #[tokio::test]
210    async fn test_detect_lua_module() {
211        let temp_dir = TempDir::new().unwrap();
212        let lua_dir = temp_dir.child("lua");
213        lua_dir.create_dir_all().unwrap();
214        let lux_file = lua_dir.child("lux.lua").to_path_buf();
215        let lux_path_expr = lua_dir.child("?.lua").to_path_buf();
216        fs::tokio::write(&lux_file, "return true").await.unwrap();
217        let package_path =
218            PackagePath::from_str(lux_path_expr.to_slash_lossy().to_string().as_str()).unwrap();
219        let package_cpath = PackagePath::default();
220        let paths = Paths::test(LuaVersion::Lua54, package_path, package_cpath);
221        let lua_cmd = which("lua")
222            .ok()
223            .or(which("luajit").ok())
224            .expect("lua not found");
225        let result = detect_lua_module(&lua_cmd, "lux", &paths, LuaEnvironment::Pure).await;
226        assert!(result, "detects module on the LUA_PATH");
227        let result = detect_lua_module(&lua_cmd, "lhflasdlkas", &paths, LuaEnvironment::Pure).await;
228        assert!(!result, "does not detect non-existing module");
229    }
230}
lux_lib/operations/run_lua.rs

lux_lib/operations/
run_lua.rs
