Merge isDisabled and isNotDisabled helpers

lib/assertions.js

@@ -8,7 +8,6 @@ import isNotRequired from './assertions/is-not-required';
 import isVisible from './assertions/is-visible';
 import isNotVisible from './assertions/is-not-visible';
 import isDisabled from './assertions/is-disabled';
-import isNotDisabled from './assertions/is-not-disabled';
 
 import elementToString from './helpers/element-to-string';
 import collapseWhitespace from './helpers/collapse-whitespace';
@@ -335,7 +334,7 @@ export default class DOMAssertions {
    * @see {@link #isDisabled}
    */
   isNotDisabled(message) {
-    isNotDisabled.call(this, message);
+    isDisabled.call(this, message, { inverted: true });
   }
 
   /**

lib/assertions/is-disabled.js

@@ -1,4 +1,6 @@
-export default function isDisabled(message) {
+export default function isDisabled(message, options = {}) {
+  let { inverted } = options;
+
   let element = this.findTargetElement();
   if (!element) return;
 
@@ -14,13 +16,15 @@ export default function isDisabled(message) {
     throw new TypeError(`Unexpected Element Type: ${element.toString()}`);
   }
 
-  let expected = `Element ${this.targetDescription} is disabled`;
-  let actual = `Element ${this.targetDescription} is disabled`;
-  let result = element.disabled;
+  let result = element.disabled === !inverted;
 
-  if (result === false) {
-    actual = `Element ${this.targetDescription} is not disabled`;
-  }
+  let actual = element.disabled === false
+    ? `Element ${this.targetDescription} is not disabled`
+    : `Element ${this.targetDescription} is disabled`;
+
+  let expected = inverted
+    ? `Element ${this.targetDescription} is not disabled`
+    : `Element ${this.targetDescription} is disabled`;
 
   if (!message) {
     message = expected;