Merge branch 'accept-jsstrings'

12 files changed, 72 insertions, 68 deletions

diff --git a/src/defs.js b/src/defs.js
index 856a854..98269ea 100644
--- a/src/defs.js
+++ b/src/defs.js
@@ -224,7 +224,13 @@ const to_luastring = function(str, cache) {
 };
 
 const from_userstring = function(str) {
-    if (!is_luastring(str)) throw new TypeError("expects an array of bytes");
+    if (!is_luastring(str)) {
+        if (typeof str === "string") {
+            str = to_luastring(str);
+        } else {
+            throw new TypeError("expects an array of bytes or javascript string");
+        }
+    }
     return str;
 };
 
diff --git a/src/lauxlib.js b/src/lauxlib.js
index 5abbaaa..475fd1b 100644
--- a/src/lauxlib.js
+++ b/src/lauxlib.js
@@ -402,16 +402,14 @@ const luaL_checktype = function(L, arg, t) {
         tag_error(L, arg, t);
 };
 
-const luaL_checkstring = function(L, n) {
-    return luaL_checklstring(L, n, null);
-};
-
 const luaL_checklstring = function(L, arg) {
     let s = lua_tolstring(L, arg);
     if (s === null || s === undefined) tag_error(L, arg, LUA_TSTRING);
     return s;
 };
 
+const luaL_checkstring = luaL_checklstring;
+
 const luaL_optlstring = function(L, arg, def) {
     if (lua_type(L, arg) <= 0) {
         return def === null ? null : from_userstring(def);
diff --git a/src/lbaselib.js b/src/lbaselib.js
index 9f0eb7a..b589d6f 100644
--- a/src/lbaselib.js
+++ b/src/lbaselib.js
@@ -156,7 +156,7 @@ const luaB_getmetatable = function(L) {
 const luaB_setmetatable = function(L) {
     let t = lua_type(L, 2);
     luaL_checktype(L, 1, LUA_TTABLE);
-    luaL_argcheck(L, t === LUA_TNIL || t === LUA_TTABLE, 2, to_luastring("nil or table expected", true));
+    luaL_argcheck(L, t === LUA_TNIL || t === LUA_TTABLE, 2, "nil or table expected");
     if (luaL_getmetafield(L, 1, to_luastring("__metatable", true)) !== LUA_TNIL)
         return luaL_error(L, to_luastring("cannot change a protected metatable"));
     lua_settop(L, 2);
@@ -173,7 +173,7 @@ const luaB_rawequal = function(L) {
 
 const luaB_rawlen = function(L) {
     let t = lua_type(L, 1);
-    luaL_argcheck(L, t === LUA_TTABLE || t === LUA_TSTRING, 1, to_luastring("table or string expected", true));
+    luaL_argcheck(L, t === LUA_TTABLE || t === LUA_TSTRING, 1, "table or string expected");
     lua_pushinteger(L, lua_rawlen(L, 1));
     return 1;
 };
@@ -201,14 +201,14 @@ const opts = [
     "isrunning"
 ].map((e) => to_luastring(e));
 const luaB_collectgarbage = function(L) {
-    luaL_checkoption(L, 1, to_luastring("collect"), opts);
+    luaL_checkoption(L, 1, "collect", opts);
     luaL_optinteger(L, 2, 0);
     luaL_error(L, to_luastring("lua_gc not implemented"));
 };
 
 const luaB_type = function(L) {
     let t = lua_type(L, 1);
-    luaL_argcheck(L, t !== LUA_TNONE, 1, to_luastring("value expected", true));
+    luaL_argcheck(L, t !== LUA_TNONE, 1, "value expected");
     lua_pushstring(L, lua_typename(L, t));
     return 1;
 };
@@ -294,7 +294,7 @@ const luaB_tonumber = function(L) {
         let base = luaL_checkinteger(L, 2);
         luaL_checktype(L, 1, LUA_TSTRING);  /* no numbers as strings */
         let s = lua_tostring(L, 1);
-        luaL_argcheck(L, 2 <= base && base <= 36, 2, to_luastring("base out of range", true));
+        luaL_argcheck(L, 2 <= base && base <= 36, 2, "base out of range");
         let n = b_str2int(s, base);
         if (n !== null) {
             lua_pushinteger(L, n);
@@ -338,7 +338,7 @@ const luaB_select = function(L) {
         let i = luaL_checkinteger(L, 1);
         if (i < 0) i = n + i;
         else if (i > n) i = n;
-        luaL_argcheck(L, 1 <= i, 1, to_luastring("index out of range", true));
+        luaL_argcheck(L, 1 <= i, 1, "index out of range");
         return n - i;
     }
 };
@@ -425,14 +425,14 @@ const generic_reader = function(L, ud) {
 
 const luaB_load = function(L) {
     let s = lua_tostring(L, 1);
-    let mode = luaL_optstring(L, 3, to_luastring("bt", true));
+    let mode = luaL_optstring(L, 3, "bt");
     let env = !lua_isnone(L, 4) ? 4 : 0;  /* 'env' index or 0 if no 'env' */
     let status;
     if (s !== null) {  /* loading a string? */
         let chunkname = luaL_optstring(L, 2, s);
         status = luaL_loadbufferx(L, s, s.length, chunkname, mode);
     } else {  /* loading from a reader function */
-        let chunkname = luaL_optstring(L, 2, to_luastring("=(load)", true));
+        let chunkname = luaL_optstring(L, 2, "=(load)");
         luaL_checktype(L, 1, LUA_TFUNCTION);
         lua_settop(L, RESERVEDSLOT);  /* create reserved slot */
         status = lua_load(L, generic_reader, null, chunkname, mode);
diff --git a/src/lcorolib.js b/src/lcorolib.js
index eb402b8..a52abf5 100644
--- a/src/lcorolib.js
+++ b/src/lcorolib.js
@@ -38,7 +38,7 @@ const { to_luastring } = require("./fengaricore.js");
 
 const getco = function(L) {
     let co = lua_tothread(L, 1);
-    luaL_argcheck(L, co, 1, to_luastring("thread expected", true));
+    luaL_argcheck(L, co, 1, "thread expected");
     return co;
 };
 
diff --git a/src/ldblib.js b/src/ldblib.js
index 9edabe7..03be3df 100644
--- a/src/ldblib.js
+++ b/src/ldblib.js
@@ -104,7 +104,7 @@ const db_getmetatable = function(L) {
 
 const db_setmetatable = function(L) {
     const t = lua_type(L, 2);
-    luaL_argcheck(L, t == LUA_TNIL || t == LUA_TTABLE, 2, to_luastring("nil or table expected", true));
+    luaL_argcheck(L, t == LUA_TNIL || t == LUA_TTABLE, 2, "nil or table expected");
     lua_settop(L, 2);
     lua_setmetatable(L, 1);
     return 1;  /* return 1st argument */
@@ -194,7 +194,7 @@ const db_getinfo = function(L) {
     let thread = getthread(L);
     let arg = thread.arg;
     let L1 = thread.thread;
-    let options = luaL_optstring(L, arg + 2, to_luastring("flnStu", true));
+    let options = luaL_optstring(L, arg + 2, "flnStu");
     checkstack(L, L1, 3);
     if (lua_isfunction(L, arg + 1)) {  /* info about a function? */
         options = lua_pushfstring(L, to_luastring(">%s"), options);  /* add '>' to 'options' */
@@ -208,7 +208,7 @@ const db_getinfo = function(L) {
     }
 
     if (!lua_getinfo(L1, options, ar))
-        luaL_argerror(L, arg + 2, to_luastring("invalid option", true));
+        luaL_argerror(L, arg + 2, "invalid option");
     lua_newtable(L);  /* table to collect results */
     if (luastring_indexOf(options, 83 /* 'S'.charCodeAt(0) */) > -1) {
         settabss(L, to_luastring("source", true), ar.source);
@@ -250,7 +250,7 @@ const db_getlocal = function(L) {
     } else {  /* stack-level argument */
         let level = luaL_checkinteger(L, arg + 1);
         if (!lua_getstack(L1, level, ar))  /* out of range? */
-            return luaL_argerror(L, arg+1, to_luastring("level out of range", true));
+            return luaL_argerror(L, arg+1, "level out of range");
         checkstack(L, L1, 1);
         let name = lua_getlocal(L1, ar, nvar);
         if (name) {
@@ -274,7 +274,7 @@ const db_setlocal = function(L) {
     let level = luaL_checkinteger(L, arg + 1);
     let nvar = luaL_checkinteger(L, arg + 2);
     if (!lua_getstack(L1, level, ar))  /* out of range? */
-        return luaL_argerror(L, arg + 1, to_luastring("level out of range", true));
+        return luaL_argerror(L, arg + 1, "level out of range");
     luaL_checkany(L, arg + 3);
     lua_settop(L, arg + 3);
     checkstack(L, L1, 1);
@@ -316,7 +316,7 @@ const db_setupvalue = function(L) {
 const checkupval = function(L, argf, argnup) {
     let nup = luaL_checkinteger(L, argnup);  /* upvalue index */
     luaL_checktype(L, argf, LUA_TFUNCTION);  /* closure */
-    luaL_argcheck(L, (lua_getupvalue(L, argf, nup) !== null), argnup, to_luastring("invalid upvalue index", true));
+    luaL_argcheck(L, (lua_getupvalue(L, argf, nup) !== null), argnup, "invalid upvalue index");
     return nup;
 };
 
@@ -329,8 +329,8 @@ const db_upvalueid = function(L) {
 const db_upvaluejoin = function(L) {
     let n1 = checkupval(L, 1, 2);
     let n2 = checkupval(L, 3, 4);
-    luaL_argcheck(L, !lua_iscfunction(L, 1), 1, to_luastring("Lua function expected", true));
-    luaL_argcheck(L, !lua_iscfunction(L, 3), 3, to_luastring("Lua function expected", true));
+    luaL_argcheck(L, !lua_iscfunction(L, 1), 1, "Lua function expected");
+    luaL_argcheck(L, !lua_iscfunction(L, 3), 3, "Lua function expected");
     lua_upvaluejoin(L, 1, n1, 3, n2);
     return 0;
 };
diff --git a/src/lmathlib.js b/src/lmathlib.js
index 665fbc4..8313e93 100644
--- a/src/lmathlib.js
+++ b/src/lmathlib.js
@@ -66,13 +66,13 @@ const math_random = function(L) {
             up = luaL_checkinteger(L, 2);
             break;
         }
-        default: return luaL_error(L, to_luastring("wrong number of arguments", true));
+        default: return luaL_error(L, "wrong number of arguments");
     }
 
     /* random integer in the interval [low, up] */
-    luaL_argcheck(L, low <= up, 1, to_luastring("interval is empty", true));
+    luaL_argcheck(L, low <= up, 1, "interval is empty");
     luaL_argcheck(L, low >= 0 || up <= LUA_MAXINTEGER + low, 1,
-        to_luastring("interval too large", true));
+        "interval too large");
 
     r *= (up - low) + 1;
     lua_pushinteger(L, Math.floor(r) + low);
@@ -213,7 +213,7 @@ const math_rad = function(L) {
 const math_min = function(L) {
     let n = lua_gettop(L);  /* number of arguments */
     let imin = 1;  /* index of current minimum value */
-    luaL_argcheck(L, n >= 1, 1, to_luastring("value expected", true));
+    luaL_argcheck(L, n >= 1, 1, "value expected");
     for (let i = 2; i <= n; i++){
         if (lua_compare(L, i, imin, LUA_OPLT))
             imin = i;
@@ -225,7 +225,7 @@ const math_min = function(L) {
 const math_max = function(L) {
     let n = lua_gettop(L);  /* number of arguments */
     let imax = 1;  /* index of current minimum value */
-    luaL_argcheck(L, n >= 1, 1, to_luastring("value expected", true));
+    luaL_argcheck(L, n >= 1, 1, "value expected");
     for (let i = 2; i <= n; i++){
         if (lua_compare(L, imax, i, LUA_OPLT))
             imax = i;
@@ -252,7 +252,7 @@ const math_fmod = function(L) {
         let d = lua_tointeger(L, 2);
         /* no special case needed for -1 in javascript */
         if (d === 0) {
-            luaL_argerror(L, 2, to_luastring("zero", true));
+            luaL_argerror(L, 2, "zero");
         } else
             lua_pushinteger(L, (lua_tointeger(L, 1) % d)|0);
     } else {
diff --git a/src/loadlib.js b/src/loadlib.js
index 533291c..f6679ba 100644
--- a/src/loadlib.js
+++ b/src/loadlib.js
@@ -361,8 +361,8 @@ const ll_searchpath = function(L) {
         L,
         luaL_checkstring(L, 1),
         luaL_checkstring(L, 2),
-        luaL_optstring(L, 3, to_luastring(".")),
-        luaL_optstring(L, 4, to_luastring(LUA_DIRSEP))
+        luaL_optstring(L, 3, "."),
+        luaL_optstring(L, 4, LUA_DIRSEP)
     );
     if (f !== null) return 1;
     else {  /* error message is on top of the stack */
diff --git a/src/loslib.js b/src/loslib.js
index 53a4228..6fec903 100644
--- a/src/loslib.js
+++ b/src/loslib.js
@@ -130,7 +130,7 @@ const checkoption = function(L, conv, i, buff) {
 
 
 const os_date = function(L) {
-    let s = luaL_optlstring(L, 1, to_luastring("%c"));
+    let s = luaL_optlstring(L, 1, "%c");
     let t = luaL_opt(L, l_checktime, 2, new Date().getTime() / 1000) * 1000;
     let stm = new Date(t);
     let utc = false;
@@ -188,7 +188,7 @@ const os_time = function(L) {
 
 const l_checktime = function(L, arg) {
     let t = luaL_checkinteger(L, arg);
-    // luaL_argcheck(L, t, arg, to_luastring("time out-of-bounds"));
+    // luaL_argcheck(L, t, arg, "time out-of-bounds");
     return t;
 };
 
diff --git a/src/lstrlib.js b/src/lstrlib.js
index fcaea79..67c4537 100644
--- a/src/lstrlib.js
+++ b/src/lstrlib.js
@@ -381,7 +381,7 @@ const str_format = function(L) {
                     if (form.length <= 2 || form[2] === 0) {  /* no modifiers? */
                         luaL_addvalue(b);  /* keep entire string */
                     } else {
-                        luaL_argcheck(L, s.length === strlen(s), arg, to_luastring("string contains zeros", true));
+                        luaL_argcheck(L, s.length === strlen(s), arg, "string contains zeros");
                         if (luastring_indexOf(form, 46 /* '.'.charCodeAt(0) */) < 0 && s.length >= 100) {
                             /* no precision and string is too long to be formatted */
                             luaL_addvalue(b);  /* keep entire string */
@@ -601,7 +601,7 @@ const str_pack = function(L) {
                 let n = luaL_checkinteger(L, arg);
                 if (size < SZINT) {  /* need overflow check? */
                     let lim = 1 << (size * 8) - 1;
-                    luaL_argcheck(L, -lim <= n && n < lim, arg, to_luastring("integer overflow", true));
+                    luaL_argcheck(L, -lim <= n && n < lim, arg, "integer overflow");
                 }
                 packint(b, n, h.islittle, size, n < 0);
                 break;
@@ -609,7 +609,7 @@ const str_pack = function(L) {
             case Kuint: {  /* unsigned integers */
                 let n = luaL_checkinteger(L, arg);
                 if (size < SZINT)
-                    luaL_argcheck(L, (n>>>0) < (1 << (size * NB)), arg, to_luastring("unsigned overflow", true));
+                    luaL_argcheck(L, (n>>>0) < (1 << (size * NB)), arg, "unsigned overflow");
                 packint(b, n>>>0, h.islittle, size, false);
                 break;
             }
@@ -625,7 +625,7 @@ const str_pack = function(L) {
             case Kchar: {  /* fixed-size string */
                 let s = luaL_checkstring(L, arg);
                 let len = s.length;
-                luaL_argcheck(L, len <= size, arg, to_luastring("string longer than given size", true));
+                luaL_argcheck(L, len <= size, arg, "string longer than given size");
                 luaL_addlstring(b, s, len);  /* add string */
                 while (len++ < size)  /* pad extra space */
                     luaL_addchar(b, LUAL_PACKPADBYTE);
@@ -636,7 +636,7 @@ const str_pack = function(L) {
                 let len = s.length;
                 luaL_argcheck(L,
                     size >= 4 /* sizeof(size_t) */ || len < (1 << (size * NB)),
-                    arg, to_luastring("string length does not fit in given size", true));
+                    arg, "string length does not fit in given size");
                 packint(b, len, h.islittle, size, 0);  /* pack length */
                 luaL_addlstring(b, s, len);
                 totalsize += len;
@@ -645,7 +645,7 @@ const str_pack = function(L) {
             case Kzstr: {  /* zero-terminated string */
                 let s = luaL_checkstring(L, arg);
                 let len = s.length;
-                luaL_argcheck(L, luastring_indexOf(s, 0) < 0, arg, to_luastring("strings contains zeros", true));
+                luaL_argcheck(L, luastring_indexOf(s, 0) < 0, arg, "strings contains zeros");
                 luaL_addlstring(b, s, len);
                 luaL_addchar(b, 0);  /* add zero at the end */
                 totalsize += len + 1;
@@ -703,7 +703,7 @@ const str_rep = function(L) {
     let s = luaL_checkstring(L, 1);
     let l = s.length;
     let n = luaL_checkinteger(L, 2);
-    let sep = luaL_optstring(L, 3, to_luastring(""));
+    let sep = luaL_optstring(L, 3, "");
     let lsep = sep.length;
     if (n <= 0) lua_pushliteral(L, "");
     else if (l + lsep < l || l + lsep > MAXSIZE / n)  /* may overflow? */
@@ -737,10 +737,10 @@ const str_byte = function(L) {
     if (pose > l) pose = l;
     if (posi > pose) return 0;  /* empty interval; return no values */
     if (pose - posi >= Number.MAX_SAFE_INTEGER)  /* arithmetic overflow? */
-        return luaL_error(L, to_luastring("string slice too long", true));
+        return luaL_error(L, "string slice too long");
 
     let n = (pose - posi) + 1;
-    luaL_checkstack(L, n, to_luastring("string slice too long", true));
+    luaL_checkstack(L, n, "string slice too long");
     for (let i = 0; i < n; i++)
         lua_pushinteger(L, s[posi + i - 1]);
     return n;
@@ -759,12 +759,12 @@ const str_packsize = function(L) {
         let size = details.size;
         let ntoalign = details.ntoalign;
         size += ntoalign;  /* total space used by option */
-        luaL_argcheck(L, totalsize <= MAXSIZE - size, 1, to_luastring("format result too large", true));
+        luaL_argcheck(L, totalsize <= MAXSIZE - size, 1, "format result too large");
         totalsize += size;
         switch (opt) {
             case Kstring:  /* strings with length count */
             case Kzstr:    /* zero-terminated string */
-                luaL_argerror(L, 1, to_luastring("variable-length format", true));
+                luaL_argerror(L, 1, "variable-length format");
                 /* call never return, but to avoid warnings: *//* fall through */
             default:  break;
         }
@@ -824,7 +824,7 @@ const str_unpack = function(L) {
     let ld = data.length;
     let pos = posrelat(luaL_optinteger(L, 3, 1), ld) - 1;
     let n = 0;  /* number of results */
-    luaL_argcheck(L, pos <= ld && pos >= 0, 3, to_luastring("initial position out of string", true));
+    luaL_argcheck(L, pos <= ld && pos >= 0, 3, "initial position out of string");
     while (fmt.off < fmt.s.length) {
         let details = getdetails(h, pos, fmt);
         let opt = details.opt;
@@ -854,7 +854,7 @@ const str_unpack = function(L) {
             }
             case Kstring: {
                 let len = unpackint(L, data.subarray(pos), h.islittle, size, 0);
-                luaL_argcheck(L, pos + len + size <= ld, 2, to_luastring("data string too short", true));
+                luaL_argcheck(L, pos + len + size <= ld, 2, "data string too short");
                 lua_pushstring(L, data.subarray(pos + size, pos + size + len));
                 pos += len;  /* skip string */
                 break;
@@ -1421,7 +1421,7 @@ const str_gsub = function(L) {
     let ms = new MatchState(L);
     let b = new luaL_Buffer();
     luaL_argcheck(L, tr === LUA_TNUMBER || tr === LUA_TSTRING || tr === LUA_TFUNCTION || tr === LUA_TTABLE, 3,
-        to_luastring("string/function/table expected", true));
+        "string/function/table expected");
     luaL_buffinit(L, b);
     if (anchor) {
         p = p.subarray(1); lp--;  /* skip anchor character */
diff --git a/src/ltablib.js b/src/ltablib.js
index 6f408da..a521720 100644
--- a/src/ltablib.js
+++ b/src/ltablib.js
@@ -105,7 +105,7 @@ const tinsert = function(L) {
             break;
         case 3: {
             pos = luaL_checkinteger(L, 2);  /* 2nd argument is the position */
-            luaL_argcheck(L, 1 <= pos && pos <= e, 2, to_luastring("position out of bounds", true));
+            luaL_argcheck(L, 1 <= pos && pos <= e, 2, "position out of bounds");
             for (let i = e; i > pos; i--) {  /* move up elements */
                 lua_geti(L, 1, i - 1);
                 lua_seti(L, 1, i);  /* t[i] = t[i - 1] */
@@ -113,7 +113,7 @@ const tinsert = function(L) {
             break;
         }
         default: {
-            return luaL_error(L, to_luastring("wrong number of arguments to 'insert'", true));
+            return luaL_error(L, "wrong number of arguments to 'insert'");
         }
     }
 
@@ -125,7 +125,7 @@ const tremove = function(L) {
     let size = aux_getn(L, 1, TAB_RW);
     let pos = luaL_optinteger(L, 2, size);
     if (pos !== size)  /* validate 'pos' if given */
-        luaL_argcheck(L, 1 <= pos && pos <= size + 1, 1, to_luastring("position out of bounds", true));
+        luaL_argcheck(L, 1 <= pos && pos <= size + 1, 1, "position out of bounds");
     lua_geti(L, 1, pos);  /* result = t[pos] */
     for (; pos < size; pos++) {
         lua_geti(L, 1, pos + 1);
@@ -150,9 +150,9 @@ const tmove = function(L) {
     checktab(L, 1, TAB_R);
     checktab(L, tt, TAB_W);
     if (e >= f) {  /* otherwise, nothing to move */
-        luaL_argcheck(L, f > 0 || e < LUA_MAXINTEGER + f, 3, to_luastring("too many elements to move", true));
+        luaL_argcheck(L, f > 0 || e < LUA_MAXINTEGER + f, 3, "too many elements to move");
         let n = e - f + 1;  /* number of elements to move */
-        luaL_argcheck(L, t <= LUA_MAXINTEGER - n + 1, 4, to_luastring("destination wrap around", true));
+        luaL_argcheck(L, t <= LUA_MAXINTEGER - n + 1, 4, "destination wrap around");
 
         if (t > e || t <= f || (tt !== 1 && lua_compare(L, 1, tt, LUA_OPEQ) !== 1)) {
             for (let i = 0; i < n; i++) {
@@ -173,7 +173,7 @@ const tmove = function(L) {
 
 const tconcat = function(L) {
     let last = aux_getn(L, 1, TAB_R);
-    let sep = luaL_optlstring(L, 2, to_luastring(""));
+    let sep = luaL_optlstring(L, 2, "");
     let lsep = sep.length;
     let i = luaL_optinteger(L, 3, 1);
     last = luaL_optinteger(L, 4, last);
@@ -335,7 +335,7 @@ const auxsort = function(L, lo, up, rnd) {
 const sort = function(L) {
     let n = aux_getn(L, 1, TAB_RW);
     if (n > 1) {  /* non-trivial interval? */
-        luaL_argcheck(L, n < LUA_MAXINTEGER, 1, to_luastring("array too big", true));
+        luaL_argcheck(L, n < LUA_MAXINTEGER, 1, "array too big");
         if (!lua_isnoneornil(L, 2))  /* is there a 2nd argument? */
             luaL_checktype(L, 2, LUA_TFUNCTION);  /* must be a function */
         lua_settop(L, 2);  /* make sure there are two arguments */
diff --git a/src/lutf8lib.js b/src/lutf8lib.js
index 3e3e194..34d1365 100644
--- a/src/lutf8lib.js
+++ b/src/lutf8lib.js
@@ -85,8 +85,8 @@ const utflen = function(L) {
     let posi = u_posrelat(luaL_optinteger(L, 2, 1), len);
     let posj = u_posrelat(luaL_optinteger(L, 3, -1), len);
 
-    luaL_argcheck(L, 1 <= posi && --posi <= len, 2, to_luastring("initial position out of string"));
-    luaL_argcheck(L, --posj < len, 3, to_luastring("final position out of string"));
+    luaL_argcheck(L, 1 <= posi && --posi <= len, 2, "initial position out of string");
+    luaL_argcheck(L, --posj < len, 3, "final position out of string");
 
     while (posi <= posj) {
         let dec = utf8_decode(s, posi);
@@ -105,7 +105,7 @@ const utflen = function(L) {
 const p_U = to_luastring("%U");
 const pushutfchar = function(L, arg) {
     let code = luaL_checkinteger(L, arg);
-    luaL_argcheck(L, 0 <= code && code <= MAXUNICODE, arg, to_luastring("value out of range", true));
+    luaL_argcheck(L, 0 <= code && code <= MAXUNICODE, arg, "value out of range");
     lua_pushfstring(L, p_U, code);
 };
 
@@ -138,14 +138,14 @@ const byteoffset = function(L) {
     let posi = n >= 0 ? 1 : s.length + 1;
     posi = u_posrelat(luaL_optinteger(L, 3, posi), s.length);
 
-    luaL_argcheck(L, 1 <= posi && --posi <= s.length, 3, to_luastring("position out of range", true));
+    luaL_argcheck(L, 1 <= posi && --posi <= s.length, 3, "position out of range");
 
     if (n === 0) {
         /* find beginning of current byte sequence */
         while (posi > 0 && iscont(s[posi])) posi--;
     } else {
         if (iscont(s[posi]))
-            luaL_error(L, to_luastring("initial position is a continuation byte", true));
+            luaL_error(L, "initial position is a continuation byte");
 
         if (n < 0) {
             while (n < 0 && posi > 0) {  /* move back */
@@ -182,19 +182,19 @@ const codepoint = function(L) {
     let posi = u_posrelat(luaL_optinteger(L, 2, 1), s.length);
     let pose = u_posrelat(luaL_optinteger(L, 3, posi), s.length);
 
-    luaL_argcheck(L, posi >= 1, 2, to_luastring("out of range", true));
-    luaL_argcheck(L, pose <= s.length, 3, to_luastring("out of range", true));
+    luaL_argcheck(L, posi >= 1, 2, "out of range");
+    luaL_argcheck(L, pose <= s.length, 3, "out of range");
 
     if (posi > pose) return 0;  /* empty interval; return no values */
     if (pose - posi >= Number.MAX_SAFE_INTEGER)
-        return luaL_error(L, to_luastring("string slice too long", true));
+        return luaL_error(L, "string slice too long");
     let n = (pose - posi) + 1;
-    luaL_checkstack(L, n, to_luastring("string slice too long", true));
+    luaL_checkstack(L, n, "string slice too long");
     n = 0;
     for (posi -= 1; posi < pose;) {
         let dec = utf8_decode(s, posi);
         if (dec === null)
-            return luaL_error(L, to_luastring("invalid UTF-8 code", true));
+            return luaL_error(L, "invalid UTF-8 code");
         lua_pushinteger(L, dec.code);
         posi = dec.pos;
         n++;
diff --git a/tests/test-suite/ltests.js b/tests/test-suite/ltests.js
index 4cadcd4..6fc086c 100644
--- a/tests/test-suite/ltests.js
+++ b/tests/test-suite/ltests.js
@@ -559,7 +559,7 @@ const newstate = function(L) {
 
 const getstate = function(L) {
     let L1 = lua.lua_touserdata(L, 1);
-    lauxlib.luaL_argcheck(L, L1 !== null, 1, to_luastring("state expected", true));
+    lauxlib.luaL_argcheck(L, L1 !== null, 1, "state expected");
     return L1;
 };
 
@@ -678,7 +678,7 @@ const panicback = function(L) {
 const checkpanic = function(L) {
     let b = new Aux();
     let code = lauxlib.luaL_checkstring(L, 1);
-    b.paniccode = lauxlib.luaL_optstring(L, 2, to_luastring("", true));
+    b.paniccode = lauxlib.luaL_optstring(L, 2, "");
     b.L = L;
     let L1 = lua.lua_newstate();    /* create new state */
     if (L1 === null) {    /* error? */
@@ -758,7 +758,7 @@ const makeCfunc = function(L) {
 const coresume = function(L) {
     let status;
     let co = lua.lua_tothread(L, 1);
-    lauxlib.luaL_argcheck(L, co, 1, to_luastring("coroutine expected", true));
+    lauxlib.luaL_argcheck(L, co, 1, "coroutine expected");
     status = lua.lua_resume(co, L, 0);
     if (status != lua.LUA_OK && status !== lua.LUA_YIELD) {
         lua.lua_pushboolean(L, 0);
@@ -812,7 +812,7 @@ const buildop = function(p, pc) {
 
 const listcode = function(L) {
     lauxlib.luaL_argcheck(L, lua.lua_isfunction(L, 1) && !lua.lua_iscfunction(L, 1),
-        1, to_luastring("Lua function expected", true));
+        1, "Lua function expected");
     let p = obj_at(L, 1);
     lua.lua_newtable(L);
     setnameval(L, to_luastring("maxstack", true), p.maxstacksize);
@@ -828,7 +828,7 @@ const listcode = function(L) {
 const listk = function(L) {
     lauxlib.luaL_argcheck(L,
         lua.lua_isfunction(L, 1) && !lua.lua_iscfunction(L, 1),
-        1, to_luastring("Lua function expected"), true);
+        1, "Lua function expected");
     let p = obj_at(L, 1);
     lua.lua_createtable(L, p.k.length, 0);
     for (let i = 0; i < p.k.length; i++) {