[mjsunit] Change assertThrows such that it can check the exception message.

test/mjsunit/wasm/divrem-trap.js

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Flags: --expose-wasm --expose-gc --allow-natives-syntax
 
 load("test/mjsunit/wasm/wasm-constants.js");
 load("test/mjsunit/wasm/wasm-module-builder.js");
 
-function assertTraps(code, msg) {
-  var threwException = true;
-  try {
-    if (typeof code === 'function') {
-      code();
-    } else {
-      eval(code);
-    }
-    threwException = false;
-  } catch (e) {
-    if (typeof type_opt === 'function') {
-      assertInstanceof(e, type_opt);
-    }
-    if (arguments.length >= 3) {
-      assertEquals(e.type, cause_opt);
-    }
-    // Success.
-    return;
-  }
-  throw new MjsUnitAssertionError("Did not throw exception");
-}
-
-
 function makeBinop(opcode) {
   var builder = new WasmModuleBuilder();
 
   builder.addFunction("main", kSig_i_ii)
     .addBody([
       kExprGetLocal, 0,           // --
       kExprGetLocal, 1,           // --
       opcode,                     // --
     ])
     .exportFunc();
 
   return builder.instantiate().exports.main;
 }
 
 var divs = makeBinop(kExprI32DivS);
 var divu = makeBinop(kExprI32DivU);
 
 assertEquals( 33, divs( 333, 10));
 assertEquals(-33, divs(-336, 10));
 
 assertEquals(       44, divu( 445, 10));
 assertEquals(429496685, divu(-446, 10));
 
-assertTraps(kTrapDivByZero, "divs(100, 0);");
-assertTraps(kTrapDivByZero, "divs(-1009, 0);");
+assertThrows(() => divs(100, 0), WebAssembly.RuntimeError,

[titzer, 2016/11/24 15:37:02]

I think we can still keep the helper function, but make it use the mjsunit
version internally, no?

[ahaas, 2016/11/28 09:47:53]

Done.

+    kTrapMsgs[kTrapDivByZero]);
+assertThrows(() => divs(-1009, 0), WebAssembly.RuntimeError,
+    kTrapMsgs[kTrapDivByZero]);
 
-assertTraps(kTrapDivByZero, "divu(200, 0);");
-assertTraps(kTrapDivByZero, "divu(-2009, 0);");
+assertThrows(() => divu(200, 0), WebAssembly.RuntimeError,
+    kTrapMsgs[kTrapDivByZero]);
+assertThrows(() => divu(-2009, 0), WebAssembly.RuntimeError,
+    kTrapMsgs[kTrapDivByZero]);
 
-assertTraps(kTrapDivUnrepresentable, "divs(0x80000000, -1)");
+assertThrows(() => divs(0x80000000, -1), WebAssembly.RuntimeError,
+    kTrapMsgs[kTrapDivUnrepresentable]);
 assertEquals(0, divu(0x80000000, -1));
 
 
 var rems = makeBinop(kExprI32RemS);
 var remu = makeBinop(kExprI32RemU);
 
 assertEquals( 3, rems( 333, 10));
 assertEquals(-6, rems(-336, 10));
 
 assertEquals( 5, remu( 445, 10));
 assertEquals( 3, remu(-443, 10));
 
-assertTraps(kTrapRemByZero, "rems(100, 0);");
-assertTraps(kTrapRemByZero, "rems(-1009, 0);");
+assertThrows(() => rems(100, 0), WebAssembly.RuntimeError,
+    kTrapMsgs[kTrapRemByZero]);
+assertThrows(() => rems(-1009, 0), WebAssembly.RuntimeError,
+    kTrapMsgs[kTrapRemByZero]);
 
-assertTraps(kTrapRemByZero, "remu(200, 0);");
-assertTraps(kTrapRemByZero, "remu(-2009, 0);");
+assertThrows(() => remu(200, 0), WebAssembly.RuntimeError,
+    kTrapMsgs[kTrapRemByZero]);
+assertThrows(() => remu(-2009, 0), WebAssembly.RuntimeError,
+    kTrapMsgs[kTrapRemByZero]);
 
 assertEquals(-2147483648, remu(0x80000000, -1));
 assertEquals(0, rems(0x80000000, -1));