implement PathSearcher

to facilitate module reloading

tests/tests.rs

@@ -1,6 +1,9 @@
-use rlua::Lua;
+use rlua::{Lua, Table, Value};
 use rlua_searcher::{AddSearcher, Result};
 use std::collections::HashMap;
+use std::fs::File;
+use std::io::Write;
+use std::path::PathBuf;
 
 #[test]
 fn add_searcher_works() {
@@ -40,6 +43,123 @@ fn add_static_searcher_works() {
     assert_eq!("hello lume", hello);
 }
 
+#[test]
+fn add_path_searcher_works() {
+    let name = "lume".to_string();
+    let path = PathBuf::new()
+        .join(std::env::var("CARGO_MANIFEST_DIR").unwrap())
+        .join("tests")
+        .join("data")
+        .join("lume.lua");
+    let mut map = HashMap::new();
+    map.insert(name, path);
+
+    let lua = Lua::new();
+
+    let hello = lua
+        .context::<_, Result<String>>(|lua_ctx| {
+            lua_ctx.add_path_searcher(map)?;
+            Ok(lua_ctx.load(r#"return require("lume")"#).eval()?)
+        })
+        .unwrap();
+
+    assert_eq!("hello lume", hello);
+}
+
+#[test]
+fn module_reloading_works() {
+    let name = "lume".to_string();
+    let path = PathBuf::new()
+        .join(std::env::var("CARGO_MANIFEST_DIR").unwrap())
+        .join("tests")
+        .join("data")
+        .join("lume.lua");
+    let mut map = HashMap::new();
+    map.insert(name.clone(), path.clone());
+
+    let lua = Lua::new();
+
+    // Add searcher for lume module on disk, and read from it.
+    let hello = lua
+        .context::<_, Result<String>>(|lua_ctx| {
+            lua_ctx.add_path_searcher(map)?;
+            Ok(lua_ctx.load(r#"return require("lume")"#).eval()?)
+        })
+        .unwrap();
+
+    assert_eq!("hello lume", hello);
+
+    // Twice.
+    let hello = lua
+        .context::<_, Result<String>>(|lua_ctx| {
+            Ok(lua_ctx.load(r#"return require("lume")"#).eval()?)
+        })
+        .unwrap();
+
+    assert_eq!("hello lume", hello);
+
+    // Modify lume module on disk.
+    let mut out = File::create(path.clone()).expect("Could not create Lume module on disk");
+    write!(out, "{}\n", r#"return "hello again lume""#)
+        .expect("Could not modify Lume module on disk");
+
+    // Thrice. Should still be unchanged due to caching.
+    let hello = lua
+        .context::<_, Result<String>>(|lua_ctx| {
+            Ok(lua_ctx.load(r#"return require("lume")"#).eval()?)
+        })
+        .unwrap();
+
+    assert_eq!("hello lume", hello);
+
+    // Remove lume module from Lua’s `package.loaded` cache to facilitate reload.
+    lua.context::<_, rlua::Result<()>>(|lua_ctx| {
+        let globals = lua_ctx.globals();
+        let loaded: Table = globals.get::<_, Table>("package")?.get("loaded")?;
+        loaded.set(name.clone(), Value::Nil)
+    })
+    .unwrap();
+
+    // Re-read from lume module on disk.
+    let hello = lua
+        .context::<_, Result<String>>(|lua_ctx| {
+            Ok(lua_ctx.load(r#"return require("lume")"#).eval()?)
+        })
+        .unwrap();
+
+    assert_eq!("hello again lume", hello);
+
+    // Twice.
+    let hello = lua
+        .context::<_, Result<String>>(|lua_ctx| {
+            Ok(lua_ctx.load(r#"return require("lume")"#).eval()?)
+        })
+        .unwrap();
+
+    assert_eq!("hello again lume", hello);
+
+    // Revert changes to lume module on disk.
+    let mut out = File::create(path).expect("Could not create Lume module on disk");
+    write!(out, "{}\n", r#"return "hello lume""#).expect("Could not modify Lume module on disk");
+
+    // Clear cache again.
+    lua.context::<_, rlua::Result<()>>(|lua_ctx| {
+        let globals = lua_ctx.globals();
+        let loaded: Table = globals.get::<_, Table>("package")?.get("loaded")?;
+        loaded.set(name, Value::Nil)
+    })
+    .unwrap();
+
+    // Ensure changes have been successfully reverted.
+    let hello = lua
+        .context::<_, Result<String>>(|lua_ctx| {
+            Ok(lua_ctx.load(r#"return require("lume")"#).eval()?)
+        })
+        .unwrap();
+
+    assert_eq!("hello lume", hello);
+}
+
 fn read_lume_to_string() -> String {
     r#"return "hello lume""#.to_string()
 }