fix: stack panic truncation (#465)

Fix stack being truncated due to double conversion to _error.

Fixes #329

global.go

@@ -165,7 +165,6 @@ func (runtime *_runtime) newDate(epoch float64) *_object {
 }
 
 func (runtime *_runtime) newError(name string, message Value, stackFramesToPop int) *_object {
-	var self *_object
 	switch name {
 	case "EvalError":
 		return runtime.newEvalError(message)
@@ -181,7 +180,7 @@ func (runtime *_runtime) newError(name string, message Value, stackFramesToPop i
 		return runtime.newURIError(message)
 	}
 
-	self = runtime.newErrorObject(name, message, stackFramesToPop)
+	self := runtime.newErrorObject(name, message, stackFramesToPop)
 	self.prototype = runtime.global.ErrorPrototype
 	if name != "" {
 		self.defineProperty("name", toValue_string(name), 0111, false)

issue_test.go

@@ -994,3 +994,26 @@ func Test_issue302(t *testing.T) {
 		})
 	}
 }
+
+func Test_issue329(t *testing.T) {
+	vm := New()
+	val, err := vm.Run(`
+		run(c);
+		var stackLen;
+		function run(fn) {
+			try {
+				fn();
+			} catch (err) {
+				stackLen = err.stack.split(/\n/).length;
+			}
+		};
+
+		function c() { d() }
+		function d() { return 'x'.join(',') }
+		stackLen;
+	`)
+	require.NoError(t, err)
+	length, err := val.Export()
+	require.NoError(t, err)
+	require.Equal(t, uint32(6), length)
+}

runtime.go

@@ -130,7 +130,7 @@ func (self *_runtime) tryCatchEvaluate(inner func() Value) (tryValue Value, exce
 			switch caught := caught.(type) {
 			case _error:
 				exception = true
-				tryValue = toValue_object(self.newError(caught.name, caught.messageValue(), 0))
+				tryValue = toValue_object(self.newErrorObjectError(caught))
 			case Value:
 				exception = true
 				tryValue = caught

type_error.go

@@ -22,3 +22,37 @@ func (rt *_runtime) newErrorObject(name string, message Value, stackFramesToPop
 
 	return self
 }
+
+func (rt *_runtime) newErrorObjectError(err _error) *_object {
+	self := rt.newClassObject(classError)
+	self.defineProperty("message", err.messageValue(), 0111, false)
+	self.value = err
+	switch err.name {
+	case "EvalError":
+		self.prototype = rt.global.EvalErrorPrototype
+	case "TypeError":
+		self.prototype = rt.global.TypeErrorPrototype
+	case "RangeError":
+		self.prototype = rt.global.RangeErrorPrototype
+	case "ReferenceError":
+		self.prototype = rt.global.ReferenceErrorPrototype
+	case "SyntaxError":
+		self.prototype = rt.global.SyntaxErrorPrototype
+	case "URIError":
+		self.prototype = rt.global.URIErrorPrototype
+	default:
+		self.prototype = rt.global.ErrorPrototype
+	}
+
+	self.defineOwnProperty("stack", _property{
+		value: _propertyGetSet{
+			rt.newNativeFunction("get", "internal", 0, func(FunctionCall) Value {
+				return toValue_string(self.value.(_error).formatWithStack())
+			}),
+			&_nilGetSetObject,
+		},
+		mode: modeConfigureMask & modeOnMask,
+	}, false)
+
+	return self
+}