[wasm] WebAssembly.Memory.grow() should handle the no instance case

test/mjsunit/wasm/js-api.js

Index: test/mjsunit/wasm/js-api.js
diff --git a/test/mjsunit/wasm/js-api.js b/test/mjsunit/wasm/js-api.js
index bea88a030affef9d79500fb9a5e015ed5d72dc19..4ccaca2c58d07e675827b1157798a44e4eeb2363 100644
--- a/test/mjsunit/wasm/js-api.js
+++ b/test/mjsunit/wasm/js-api.js
@@ -373,29 +373,31 @@ assertEq(memGrowDesc.configurable, true);
 
 // 'WebAssembly.Memory.prototype.grow' method
 
-if (false) { // TODO: bugs with Memory.grow
 let memGrow = memGrowDesc.value;
 assertEq(memGrow.length, 1);
-assertErrorMessage(() => memGrow.call(), TypeError, /called on incompatible undefined/);
-assertErrorMessage(() => memGrow.call({}), TypeError, /called on incompatible Object/);
-assertErrorMessage(() => memGrow.call(mem1, -1), RangeError, /bad Memory grow delta/);
-assertErrorMessage(() => memGrow.call(mem1, Math.pow(2,32)), RangeError, /bad Memory grow delta/);
+assertErrorMessage(() => memGrow.call(), TypeError,
+    /called on incompatible undefined/);
+assertErrorMessage(() => memGrow.call({}), TypeError,
+    /called on incompatible Object/);
+assertErrorMessage(() => memGrow.call(mem1, -1), RangeError,
+    /bad Memory grow delta/);
+assertErrorMessage(() => memGrow.call(mem1, Math.pow(2,32)), RangeError,
+    /bad Memory grow delta/);
 var mem = new Memory({initial:1, maximum:2});
 var buf = mem.buffer;
 assertEq(buf.byteLength, kPageSize);
 assertEq(mem.grow(0), 1);
-assertEq(buf !== mem.buffer, true);
-assertEq(buf.byteLength, 0);
+// TODO(gdeepti): assertEq(buf !== mem.buffer, true);

[bradnelson, 2017/01/18 02:35:37]

Maybe say pending spec clarification (ideally ref the filled github issue)

[gdeepti, 2017/01/18 04:43:14]

Done.

+// TODO(gdeepti): assertEq(buf.byteLength, 0);
 buf = mem.buffer;
 assertEq(buf.byteLength, kPageSize);
 assertEq(mem.grow(1), 1);
-assertEq(buf !== mem.buffer, true);
-assertEq(buf.byteLength, 0);
+// TODO(gdeepti): assertEq(buf !== mem.buffer, true);
+// TODO(gdeepti): assertEq(buf.byteLength, 0);

[gdeepti, 2017/01/18 02:17:47]

Disabled for now because for the 0 case, we do not allocate a new buffer, second
case fails with guard pages enabled. 

 buf = mem.buffer;
 assertEq(buf.byteLength, 2 * kPageSize);
 assertErrorMessage(() => mem.grow(1), Error, /failed to grow memory/);
 assertEq(buf, mem.buffer);
-}
 
 // 'WebAssembly.Table' data property
 let tableDesc = Object.getOwnPropertyDescriptor(WebAssembly, 'Table');