Add version information to lua module

distant-lua/src/lib.rs

@@ -23,10 +23,36 @@ mod utils;
 fn distant_lua(lua: &Lua) -> LuaResult<LuaTable> {
     let exports = lua.create_table()?;
 
-    exports.set("PENDING", utils::pending(lua)?)?;
+    // Provide a static pending type used when consumer wants to use async functions
+    // directly without wrapping them with a scheduler
+    exports.set("pending", utils::pending(lua)?)?;
+
+    // API modules available for users
     exports.set("log", log::make_log_tbl(lua)?)?;
     exports.set("session", session::make_session_tbl(lua)?)?;
     exports.set("utils", utils::make_utils_tbl(lua)?)?;
+    exports.set("version", make_version_tbl(lua)?)?;
 
     Ok(exports)
 }
+
+macro_rules! set_nonempty_env {
+    ($tbl:ident, $key:literal, $env_key:literal) => {{
+        let value = env!($env_key);
+        if !value.is_empty() {
+            $tbl.set($key, value)?;
+        }
+    }};
+}
+
+fn make_version_tbl(lua: &Lua) -> LuaResult<LuaTable> {
+    let tbl = lua.create_table()?;
+
+    set_nonempty_env!(tbl, "full", "CARGO_PKG_VERSION");
+    set_nonempty_env!(tbl, "major", "CARGO_PKG_VERSION_MAJOR");
+    set_nonempty_env!(tbl, "minor", "CARGO_PKG_VERSION_MINOR");
+    set_nonempty_env!(tbl, "patch", "CARGO_PKG_VERSION_PATCH");
+    set_nonempty_env!(tbl, "pre", "CARGO_PKG_VERSION_PRE");
+
+    Ok(tbl)
+}