wplua: enable the use of require() to load lua libraries from scripts/lib

modules/module-lua-scripting/module.c

@@ -53,6 +53,64 @@ execute_script (lua_State *L, struct ScriptData * s, GError ** error)
   return wplua_pcall (L, nargs, 0, error);
 }
 
+static int
+wp_lua_scripting_package_loader (lua_State *L)
+{
+  luaL_checktype (L, 2, LUA_TFUNCTION);
+  wplua_push_sandbox (L);
+  lua_pushvalue (L, 2);
+  lua_call (L, 1, 1);
+  return 1;
+}
+
+static int
+wp_lua_scripting_package_searcher (lua_State *L)
+{
+  const gchar *name = luaL_checkstring (L, 1);
+  g_autoptr (GError) error = NULL;
+  g_autofree gchar *filename = g_strdup_printf ("%s.lua", name);
+  g_autofree gchar *script = wp_find_file (
+      WP_LOOKUP_DIR_ENV_DATA |
+      WP_LOOKUP_DIR_XDG_CONFIG_HOME |
+      WP_LOOKUP_DIR_ETC |
+      WP_LOOKUP_DIR_PREFIX_SHARE,
+      filename, "scripts/lib");
+
+  if (!script)  {
+    lua_pushliteral (L, "script not found");
+    return 1;
+  }
+
+  /* 1. loader (function) */
+  lua_pushcfunction (L, wp_lua_scripting_package_loader);
+
+  /* 2. loader data (param to 1) */
+  if (!wplua_load_path (L, script, &error)) {
+    lua_pop (L, 1);
+    lua_pushstring (L, error->message);
+    return 1;
+  }
+
+  /* 3. script path */
+  lua_pushstring (L, script);
+  return 3;
+}
+
+static void
+wp_lua_scripting_enable_package_searcher (lua_State *L)
+{
+  /* table.insert(package.searchers, 2, wp_lua_scripting_package_searcher) */
+  lua_getglobal (L, "table");
+  lua_getfield (L, -1, "insert");
+  lua_remove (L, -2);
+  lua_getglobal (L, "package");
+  lua_getfield (L, -1, "searchers");
+  lua_remove (L, -2);
+  lua_pushinteger (L, 2);
+  lua_pushcfunction (L, wp_lua_scripting_package_searcher);
+  lua_call (L, 3, 0);
+}
+
 G_DECLARE_FINAL_TYPE (WpLuaScriptingPlugin, wp_lua_scripting_plugin,
                       WP, LUA_SCRIPTING_PLUGIN, WpComponentLoader)
 G_DEFINE_TYPE (WpLuaScriptingPlugin, wp_lua_scripting_plugin,
@@ -99,6 +157,7 @@ wp_lua_scripting_plugin_enable (WpPlugin * plugin, WpTransition * transition)
   lua_settable (self->L, LUA_REGISTRYINDEX);
 
   wp_lua_scripting_api_init (self->L);
+  wp_lua_scripting_enable_package_searcher (self->L);
   wplua_enable_sandbox (self->L, WP_LUA_SANDBOX_ISOLATE_ENV);
 
   /* execute scripts that were queued in for loading */

modules/module-lua-scripting/wplua/sandbox.lua

@@ -38,7 +38,7 @@ else
   -- full list, used for scripts
   ([[
     _VERSION assert error    ipairs   next pairs  print
-    pcall    select tonumber tostring type xpcall
+    pcall    select tonumber tostring type xpcall require
 
     table utf8
 
@@ -76,6 +76,8 @@ for k, v in pairs(SANDBOX_ENV) do
   end
 end
 
+populate_env("package")
+
 if SANDBOX_CONFIG["isolate_env"] then
   -- in isolate_env mode, use a separate enviornment for each loaded chunk and
   -- store all of them in a global table so that they are not garbage collected
@@ -92,7 +94,7 @@ if SANDBOX_CONFIG["isolate_env"] then
     -- set it as the chunk's 1st upvalue (__ENV)
     debug.setupvalue(chunk, 1, env)
     -- execute the chunk
-    chunk(...)
+    return chunk(...)
   end
 else
   -- in common_env mode, use the same environment for all loaded chunks
@@ -106,6 +108,6 @@ else
     -- set it as the chunk's 1st upvalue (__ENV)
     debug.setupvalue(chunk, 1, SANDBOX_COMMON_ENV)
     -- execute the chunk
-    chunk(...)
+    return chunk(...)
   end
 end

modules/module-lua-scripting/wplua/wplua.c

@@ -23,7 +23,7 @@ _wplua_openlibs (lua_State *L)
    * http://www.lua.org/source/5.3/linit.c.html */
   static const luaL_Reg loadedlibs[] = {
     {"_G", luaopen_base},
-    /* {LUA_LOADLIBNAME, luaopen_package}, */
+    {LUA_LOADLIBNAME, luaopen_package},
     /* {LUA_COLIBNAME, luaopen_coroutine}, */
     {LUA_TABLIBNAME, luaopen_table},
     /* {LUA_IOLIBNAME, luaopen_io}, */

tests/wplua/meson.build

@@ -37,3 +37,9 @@ test(
   args: ['monitor-rules.lua'],
   env: common_env,
 )
+test(
+  'test-lua-require',
+  script_tester,
+  args: ['require.lua'],
+  env: common_env,
+)

tests/wplua/scripts/lib/testlib.lua

@@ -0,0 +1,9 @@
+local testlib = {}
+
+function testlib.test_add_ten (x)
+  return x + 10
+end
+
+Log.info("in testlib")
+
+return testlib

tests/wplua/scripts/require.lua

@@ -0,0 +1,8 @@
+local testlib = require("testlib")
+
+assert(type(testlib) == "table")
+assert(package.loaded["testlib"] == testlib)
+
+local x = 1
+x = testlib.test_add_ten(x)
+assert(x == 11)