__newindex

3 files changed, 95 insertions, 1 deletions

diff --git a/src/ltm.js b/src/ltm.js
index fc0d0ec..c712160 100644
--- a/src/ltm.js
+++ b/src/ltm.js
@@ -1,6 +1,8 @@
 /*jshint esversion: 6 */
 "use strict";
 
+const assert  = require('assert');
+
 const lobject = require('./lobject.js');
 const TValue  = lobject.TValue;
 const Table   = lobject.Table;
@@ -56,6 +58,7 @@ const luaT_callTM = function(L, f, p1, p2, p3, hasres) {
         ldo.luaD_callnoyield(L, func, hasres);
 
     if (hasres) {
+        assert(typeof result === "number");
         L.stack[result] = L.stack[--L.top];
     }
 };
diff --git a/src/lvm.js b/src/lvm.js
index b0b5d53..cd9548e 100644
--- a/src/lvm.js
+++ b/src/lvm.js
@@ -1006,7 +1006,7 @@ const luaV_finishset = function(L, t, key, val, slot, recur) {
     }
 
     if (tm.ttisfunction()) {
-        ltm.luaT_callTM(L, tm, t, key, val, 1);
+        ltm.luaT_callTM(L, tm, t, key, val, 0);
         return;
     }
 
diff --git a/tests/ltm.js b/tests/ltm.js
index 5644ae8..e7085cd 100644
--- a/tests/ltm.js
+++ b/tests/ltm.js
@@ -164,4 +164,95 @@ test('__index function in metatable', function (t) {
         "__index",
         "Program output is correct"
     );
+});
+
+
+test('__newindex function in metatable', function (t) {
+    let luaCode = `
+        local mt = {
+            __newindex = function (table, key, value)
+                return "__newindex"
+            end
+        }
+
+        local t = {}
+
+        -- setmetatable(t, mt)
+
+        t.yo = "hello"
+
+        return t.yo
+    `, L;
+    
+    t.plan(8);
+
+    t.comment("Running following code: \n" + luaCode);
+
+    t.doesNotThrow(function () {
+        L = getState(luaCode);
+    }, "Bytecode parsed without errors");
+
+
+    // main <hello.lua:0,0> (8 instructions at 0x7faadcf00ac0)
+    // 0+ params, 3 slots, 1 upvalue, 2 locals, 3 constants, 1 function
+    //         1       [1]     NEWTABLE        0 0 1
+    //         2       [4]     CLOSURE         1 0     ; 0x7faadcf00d10
+    //         3       [4]     SETTABLE        0 -1 1  ; "__newindex" -
+    //         4       [7]     NEWTABLE        1 0 0
+    //         5       [11]    SETTABLE        1 -2 -3 ; "yo" "hello"   <=== We stop here
+    //         6       [13]    GETTABLE        2 1 -2  ; "yo"
+    //         7       [13]    RETURN          2 2
+    //         8       [13]    RETURN          0 1
+    //
+    // function <hello.lua:2,4> (3 instructions at 0x7faadcf00d10)
+    // 3 params, 4 slots, 0 upvalues, 3 locals, 1 constant, 0 functions
+    //         1       [3]     LOADK           3 -1    ; "__newindex"
+    //         2       [3]     RETURN          3 2
+    //         3       [4]     RETURN          0 1
+
+    t.strictEqual(
+        OC.OpCodes[L.stack[0].p.code[4].opcode],
+        "OP_SETTABLE",
+        "Correct opcode marked as breakpoint"
+    );
+
+    t.comment("We set a breakpoint just before 'return t.yo'")
+    L.stack[0].p.code[4].breakpoint = true; // Stop just before 'return t.yo'
+
+    t.doesNotThrow(function () {
+        VM.luaV_execute(L);
+    }, "First part of the program executed without errors");
+
+    t.strictEqual(
+        OC.OpCodes[L.ci.u.l.savedpc[L.ci.pcOff - 1].opcode],
+        "OP_SETTABLE",
+        "Stopped at correct opcode"
+    );
+
+    t.comment("We unset the breakpoint and correct pcOff");
+    L.ci.pcOff--;
+    L.stack[0].p.code[4].breakpoint = false;
+
+    t.ok(
+        L.stack[2].ttistable() && !L.stack[2].value.hash.get("__newindex"),
+        "t is on stack at 2"
+    );
+
+    t.ok(
+        L.stack[1].ttistable() && L.stack[1].value.hash.get("__newindex"),
+        "mt is on stack at 1"
+    );
+
+    t.comment("We manually set t's metatable to mt");
+    L.stack[2].metatable = L.stack[1];
+
+    t.doesNotThrow(function () {
+        VM.luaV_execute(L);
+    }, "Second part of the program executed without errors");
+
+    t.strictEqual(
+        L.stack[L.top - 1].value,
+        null,
+        "Program output is correct"
+    );
 });
\ No newline at end of file