Add lua.to_uristring

5 files changed, 25 insertions, 7 deletions

diff --git a/README.md b/README.md
index 0d10e5f..eefbeea 100644
--- a/README.md
+++ b/README.md
@@ -45,7 +45,7 @@ Fengari implements Lua 5.3 semantics and will hopefully follow future Lua releas
 
 Lua strings are 8-bits clean and can embed `\0`. Which means that invalid UTF-8/16 strings are valid Lua strings. Lua functions like `string.dump` even use strings as a way of storing binary data.
 
-To address that issue, Lua strings are represented by an array of bytes in Fengari. To push a JS string on the stack you can use `lua_pushliteral` which will convert it to an array of bytes before pushing it. To get a Lua string on the stack as a JS string you can use `lua_tojsstring` which will attempt to convert it to a UTF-16 JS string. The latter won't give you what you expect if the Lua string is not a valid UTF-16 sequence. You can also convert strings with `lua.to_luastring` and `lua.to_jsstring`.
+To address that issue, Lua strings are represented by an array of bytes in Fengari. To push a JS string on the stack you can use `lua_pushliteral` which will convert it to an array of bytes before pushing it. To get a Lua string on the stack as a JS string you can use `lua_tojsstring` which will attempt to convert it to a UTF-16 JS string. The latter won't give you what you expect if the Lua string is not a valid UTF-16 sequence. You can also convert strings with `lua.to_luastring`, `lua.to_jsstring` and `lua.to_uristring`.
 
 ### Integers
 
diff --git a/src/defs.js b/src/defs.js
index 315364a..3ebb747 100644
--- a/src/defs.js
+++ b/src/defs.js
@@ -188,6 +188,25 @@ const to_jsstring = function(value, from, to) {
     return str;
 };
 
+const uri_allowed = {}; /* bytes allowed unescaped in a uri */
+for (let c of ";,/?:@&=+$abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789,-_.!~*'()#") {
+    uri_allowed[c.charCodeAt(0)] = true;
+}
+
+/* utility function to convert a lua string to a js string with uri escaping */
+const to_uristring = function(a) {
+    let s = "";
+    for (let i=0; i<a.length; i++) {
+        let v = a[i];
+        if (uri_allowed[v]) {
+            s += String.fromCharCode(v);
+        } else {
+            s += "%" + (v<0x10?"0":"") + v.toString(16);
+        }
+    }
+    return s;
+};
+
 const to_luastring_cache = {};
 
 const to_luastring = function(str, cache) {
@@ -405,3 +424,4 @@ module.exports.is_luastring            = is_luastring;
 module.exports.luastring_cmp           = luastring_cmp;
 module.exports.to_jsstring             = to_jsstring;
 module.exports.to_luastring            = to_luastring;
+module.exports.to_uristring            = to_uristring;
diff --git a/src/lauxlib.js b/src/lauxlib.js
index 8d110ea..62fc6f3 100644
--- a/src/lauxlib.js
+++ b/src/lauxlib.js
@@ -740,8 +740,7 @@ if (WEB) {
         } else {
             lua.lua_pushfstring(L, lua.to_luastring("@%s"), filename);
 
-            let path = lua.to_jsstring(filename);
-            path = encodeURI(path);
+            let path = lua.to_uristring(filename);
             let xhr = new XMLHttpRequest();
             xhr.open("GET", path, false);
             // TODO: find a way to load bytes instead of js string
diff --git a/src/loadlib.js b/src/loadlib.js
index 8ae758b..49f2715 100644
--- a/src/loadlib.js
+++ b/src/loadlib.js
@@ -38,8 +38,7 @@ const AUXMARK       = [1];
 let lsys_load;
 if (WEB) {
     lsys_load = function(L, path, seeglb) {
-        path = lua.to_jsstring(path);
-        path = encodeURI(path);
+        path = lua.to_uristring(path);
         let xhr = new XMLHttpRequest();
         xhr.open("GET", path, false);
         xhr.send();
@@ -129,8 +128,7 @@ if (!WEB) {
 } else {
     /* TODO: use async/await ? */
     readable = function(path) {
-        path = lua.to_jsstring(path);
-        path = encodeURI(path);
+        path = lua.to_uristring(path);
         let xhr = new XMLHttpRequest();
         /* Following GET request done by searcher_Web will be cached */
         xhr.open("GET", path, false);
diff --git a/src/lua.js b/src/lua.js
index 84414de..ab1820f 100644
--- a/src/lua.js
+++ b/src/lua.js
@@ -80,6 +80,7 @@ module.exports.lua_Debug               = defs.lua_Debug;
 module.exports.lua_upvalueindex        = defs.lua_upvalueindex;
 module.exports.to_jsstring             = defs.to_jsstring;
 module.exports.to_luastring            = defs.to_luastring;
+module.exports.to_uristring            = defs.to_uristring;
 module.exports.LUA_CDIR                = defs.LUA_CDIR;
 module.exports.LUA_CPATH_DEFAULT       = defs.LUA_CPATH_DEFAULT;
 module.exports.LUA_EXEC_DIR            = defs.LUA_EXEC_DIR;