Add doesNotIncludeText() assertion

API.md

@@ -224,6 +224,26 @@ attribute.
 assert.dom('#title').includesText('Welcome');
 ```
 
+### doesNotIncludeText
+
+Assert that the text of the [HTMLElement][] or an [HTMLElement][]
+matching the `selector` does not include the given `text`, using the
+[`textContent`](https://developer.mozilla.org/en-US/docs/Web/API/Node/textContent)
+attribute.
+
+**Aliases:** `doesNotContainText`, `doesNotHaveTextContaining`
+
+**Parameters**
+
+-   `text` **[string](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)** 
+-   `message` **[string](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)?** 
+
+**Examples**
+
+```javascript
+assert.dom('#title').doesNotIncludeText('Welcome');
+```
+
 ### hasValue
 
 -   **See: [#hasAnyValue](#hasanyvalue)**

lib/__tests__/does-not-include-text.js

@@ -0,0 +1,109 @@
+/* eslint-env jest */
+
+import TestAssertions from "../helpers/test-assertions";
+
+describe('assert.dom(...).doesNotIncludeText()', () => {
+  let assert;
+
+  beforeEach(() => {
+    assert = new TestAssertions();
+  });
+
+  test('with custom message', () => {
+    document.body.innerHTML = '<h1 class="baz">foo</h1>bar';
+
+    assert.dom('h1').doesNotIncludeText('baz', 'bing');
+
+    expect(assert.results).toEqual([{
+      actual: "Element h1 does not include text \"baz\"",
+      expected: "Element h1 does not include text \"baz\"",
+      message: 'bing',
+      result: true,
+    }]);
+  });
+
+  describe('with HTMLElement', () => {
+    let element;
+
+    beforeEach(() => {
+      document.body.innerHTML = '<h1 class="baz">foo</h1>bar';
+      element = document.querySelector('h1');
+    });
+
+    test('succeeds for correct content', () => {
+      assert.dom(element).doesNotIncludeText('baz');
+
+      expect(assert.results).toEqual([{
+        actual: "Element h1.baz does not include text \"baz\"",
+        expected: "Element h1.baz does not include text \"baz\"",
+        message: 'Expected element h1.baz to not include text "baz"',
+        result: true,
+      }]);
+    });
+
+    test('fails for wrong content', () => {
+      assert.dom(element).doesNotIncludeText('foo');
+
+      expect(assert.results).toEqual([{
+        actual: 'Element h1.baz includes text "foo"',
+        expected: 'Element h1.baz does not include text "foo"',
+        message: 'Expected element h1.baz to not include text "foo"',
+        result: false,
+      }]);
+    });
+
+    test('fails for missing element', () => {
+      assert.dom(null).doesNotIncludeText('foo');
+
+      expect(assert.results).toEqual([{
+        message: 'Element <unknown> exists',
+        result: false,
+      }]);
+    });
+  });
+
+  describe('with selector', () => {
+    beforeEach(() => {
+      document.body.innerHTML = '<h1 class="baz">foo</h1>bar';
+    });
+
+    test('succeeds for correct content', () => {
+      assert.dom('h1').doesNotIncludeText('bar');
+
+      expect(assert.results).toEqual([{
+        actual: 'Element h1 does not include text "bar"',
+        expected: 'Element h1 does not include text "bar"',
+        message: 'Expected element h1 to not include text "bar"',
+        result: true,
+      }]);
+    });
+
+    test('fails for wrong content', () => {
+      assert.dom('h1').doesNotIncludeText('foo');
+
+      expect(assert.results).toEqual([{
+        actual: 'Element h1 includes text "foo"',
+        expected: 'Element h1 does not include text "foo"',
+        message: 'Expected element h1 to not include text "foo"',
+        result: false,
+      }]);
+    });
+
+    test('fails for missing element', () => {
+      assert.dom('h2').doesNotIncludeText('foo');
+
+      expect(assert.results).toEqual([{
+        message: 'Element h2 exists',
+        result: false,
+      }]);
+    });
+  });
+
+  test('throws for unexpected parameter types', () => {
+    expect(() => assert.dom(5).doesNotIncludeText('foo')).toThrow('Unexpected Parameter: 5');
+    expect(() => assert.dom(true).doesNotIncludeText('foo')).toThrow('Unexpected Parameter: true');
+    expect(() => assert.dom(undefined).doesNotIncludeText('foo')).toThrow('Unexpected Parameter: undefined');
+    expect(() => assert.dom({}).doesNotIncludeText('foo')).toThrow('Unexpected Parameter: [object Object]');
+    expect(() => assert.dom(document).doesNotIncludeText('foo')).toThrow('Unexpected Parameter: [object HTMLDocument]');
+  });
+});

lib/assertions.js

@@ -327,6 +327,47 @@ export default class DOMAssertions {
     this.includesText(expected, message);
   }
 
+  /**
+   * Assert that the text of the [HTMLElement][] or an [HTMLElement][]
+   * matching the `selector` does not include the given `text`, using the
+   * [`textContent`](https://developer.mozilla.org/en-US/docs/Web/API/Node/textContent)
+   * attribute.
+   *
+   * **Aliases:** `doesNotContainText`, `doesNotHaveTextContaining`
+   *
+   * @param {string} text
+   * @param {string?} message
+   *
+   * @example
+   * assert.dom('#title').doesNotIncludeText('Welcome');
+   */
+  doesNotIncludeText(text, message) {
+    let element = this.findTargetElement();
+    if (!element) return;
+
+    let result = element.textContent.indexOf(text) === -1;
+    let expected = `Element ${this.targetDescription} does not include text "${text}"`;
+    let actual = expected;
+
+    if(!result) {
+      actual = `Element ${this.targetDescription} includes text "${text}"`;
+    }
+
+    if (!message) {
+      message = `Expected element ${this.targetDescription} to not include text "${text}"`;
+    }
+
+    this.pushResult({ result, actual, expected, message });
+  }
+
+  doesNotContainText(unexpected, message) {
+    this.doesNotIncludeText(unexpected, message);
+  }
+
+  doesNotHaveTextContaining(unexpected, message) {
+    this.doesNotIncludeText(unexpected, message);
+  }
+
   /**
    * Assert that the `value` property of an [HTMLInputElement][] matches
    * the `expected` text or regular expression.