From ee05d5644a8ae872c9b8c8b437651b3f34d88591 Mon Sep 17 00:00:00 2001
From: Benoit Giannangeli <giann008@gmail.com>
Date: Wed, 3 May 2017 15:53:15 +0200
Subject: package.loadlib

---
 README.md              |  2 +-
 src/loadlib.js         | 54 ++++++++++++++++++++++++++++++++++++++++----------
 tests/lib-hello.js.mod |  8 ++++++++
 tests/loadlib.js       | 32 ++++++++++++++++++++++++++++++
 4 files changed, 85 insertions(+), 11 deletions(-)
 create mode 100644 tests/lib-hello.js.mod

diff --git a/README.md b/README.md
index 8b31831..16701df 100644
--- a/README.md
+++ b/README.md
@@ -27,11 +27,11 @@
         - [x] `package.config`
         - [x] `package.cpath`
         - [x] `package.loaded`
+        - [x] `package.loadlib`
         - [x] `package.path`
         - [x] `package.preload`
         - [x] `package.searchers`
         - [x] `require`
-        - [ ] `package.loadlib`
         - [ ] `package.searchpath`
     - [ ] io
         - [x] `file:__tostring()`
diff --git a/src/loadlib.js b/src/loadlib.js
index 5ed4703..f25e5dc 100644
--- a/src/loadlib.js
+++ b/src/loadlib.js
@@ -34,20 +34,38 @@ const AUXMARK       = [1];
 const LIB_FAIL      = "absent";
 const DLMSG         = "dynamic libraries not enabled; check your Lua installation";
 
+/*
+** load JS library in file 'path'. If 'seeglb', load with all names in
+** the library global.
+** Returns the library; in case of error, returns NULL plus an
+** error string in the stack.
+*/
+const lsys_load = function(L, path) {
+    try {
+        path = lua.to_jsstring(path);
 
-const lsys_unloadlib = function(lib) {
-};
-
+        // Relative path ?
+        if (path.startsWith('.'))
+            path = `${process.env.PWD}/${path}`;
 
-const lsys_load = function(L, path, seeglb) {
-    lua.lua_pushliteral(L, DLMSG);
-    return null;
+        return require(path);
+    } catch (e) {
+        lua.lua_pushjsstring(L, e.message);
+    }
 };
 
-
+/*
+** Try to find a function named 'sym' in library 'lib'.
+** Returns the function; in case of error, returns NULL plus an
+** error string in the stack.
+*/
 const lsys_sym = function(L, lib, sym) {
-    lua.lua_pushliteral(L, DLMSG);
-    return null;
+    let f = lib[lua.to_jsstring(sym)];
+
+    if (f && typeof f === 'function')
+        return f;
+
+    lua.lua_pushliteral(L, `'${lua.to_jsstring(sym)}'`);
 };
 
 /*
@@ -109,6 +127,20 @@ const lookforfunc = function(L, path, sym) {
     }
 };
 
+const ll_loadlib = function(L) {
+    let path = lauxlib.luaL_checkstring(L, 1);
+    let init = lauxlib.luaL_checkstring(L, 2);
+    let stat = lookforfunc(L, path, init);
+    if (stat === 0)  /* no errors? */
+        return 1;  /* return the loaded function */
+    else {  /* error; error message is on stack top */
+        lua.lua_pushnil(L);
+        lua.lua_insert(L, -2);
+        lua.lua_pushjsstring(L, (stat === ERRLIB) ? LIB_FAIL : "init");
+        return 3;  /* return nil, error message, and where */
+    }
+};
+
 /*
 ** Set a path
 */
@@ -315,7 +347,9 @@ const ll_require = function(L) {
     return 1;
 };
 
-const pk_funcs = {};
+const pk_funcs = {
+    "loadlib": ll_loadlib
+};
 
 const ll_funcs = {
     "require": ll_require
diff --git a/tests/lib-hello.js.mod b/tests/lib-hello.js.mod
new file mode 100644
index 0000000..d4c02e1
--- /dev/null
+++ b/tests/lib-hello.js.mod
@@ -0,0 +1,8 @@
+const lua      = require('../src/lua.js');
+
+module.exports = {
+    "hello": function(L) {
+        lua.lua_pushliteral(L, "hello from js lib");
+        return 1;
+    }
+};
diff --git a/tests/loadlib.js b/tests/loadlib.js
index 933991c..b840bf5 100644
--- a/tests/loadlib.js
+++ b/tests/loadlib.js
@@ -66,3 +66,35 @@ test('require a file', function (t) {
     );
 
 });
+
+
+test('package.loadlib', function (t) {
+    let luaCode = `
+        return package.loadlib('./tests/lib-hello.js.mod', 'hello')()
+    `, L;
+    
+    t.plan(3);
+
+    t.doesNotThrow(function () {
+
+        L = lauxlib.luaL_newstate();
+
+        lauxlib.luaL_openlibs(L);
+
+        lauxlib.luaL_loadstring(L, lua.to_luastring(luaCode));
+
+    }, "Lua program loaded without error");
+
+    t.doesNotThrow(function () {
+
+        lua.lua_call(L, 0, -1);
+
+    }, "Lua program ran without error");
+
+    t.strictEqual(
+        lua.lua_tojsstring(L, -1),
+        "hello from js lib",
+        "Correct element(s) on the stack"
+    );
+
+});
-- 
cgit v1.2.3-54-g00ecf