Add tests for #1870

test-utils/domMock.js

@@ -345,18 +345,22 @@ module.exports = function(options) {
 				if (element.nodeName === "TEXTAREA") {
 					var wasNeverSet = true
 					var value = ""
+					var valueSetter = spy(function(v) {
+						wasNeverSet = false
+						/*eslint-disable no-implicit-coercion*/
+						value = v === null ? "" : "" + v
+						/*eslint-enable no-implicit-coercion*/
+					})
 					Object.defineProperty(element, "value", {
 						get: function() {
 							return wasNeverSet && this.firstChild ? this.firstChild.nodeValue : value
 						},
-						set: function(v) {
-							wasNeverSet = false
-							/*eslint-disable no-implicit-coercion*/
-							value = v === null ? "" : "" + v
-							/*eslint-enable no-implicit-coercion*/
-						},
+						set: valueSetter,
 						enumerable: true,
 					})
+					registerSpies(element, {
+						valueSetter: valueSetter
+					})
 				}
 
 				/* eslint-disable radix */

test-utils/tests/test-domMock.js

@@ -1237,5 +1237,21 @@ o.spec("domMock", function() {
 			o(spies.valueSetter.this).equals(option)
 			o(spies.valueSetter.args[0]).equals("aaa")
 		})
+		o("textarea elements have spies on value setters", function() {
+			var textarea = $window.document.createElement("textarea")
+
+			var spies = $window.__getSpies(textarea)
+
+			o(typeof spies).equals("object")
+			o(spies).notEquals(null)
+			o(typeof spies.valueSetter).equals("function")
+			o(spies.valueSetter.callCount).equals(0)
+
+			textarea.value = "aaa"
+
+			o(spies.valueSetter.callCount).equals(1)
+			o(spies.valueSetter.this).equals(textarea)
+			o(spies.valueSetter.args[0]).equals("aaa")
+		})
 	})
 })