add tests for toHaveDisplayValue()

Author: jaworek

src/matchers/__tests__/to-have-display-value.tsx

@@ -0,0 +1,72 @@
+import * as React from 'react';
+import { TextInput, View } from 'react-native';
+import { render, screen } from '../..';
+import '../extend-expect';
+
+test('example test', () => {
+  render(<TextInput testID="text-input" value="test" />);
+
+  const textInput = screen.getByTestId('text-input');
+
+  expect(textInput).toHaveDisplayValue('test');
+});
+
+test('toHaveDisplayValue() on matching display value', () => {
+  render(<TextInput testID="text-input" value="test" />);
+
+  const textInput = screen.getByTestId('text-input');
+
+  expect(textInput).toHaveDisplayValue('test');
+});
+
+test('toHaveDisplayValue() on not matching display value', () => {
+  render(<TextInput testID="text-input" value="test" />);
+
+  const textInput = screen.getByTestId('text-input');
+
+  expect(textInput).not.toHaveDisplayValue('non-test');
+});
+
+test("toHaveDisplayValue() on non 'TextInput' elements", () => {
+  render(<View testID="view" />);
+
+  const view = screen.getByTestId('view');
+
+  expect(() =>
+    expect(view).not.toHaveDisplayValue('test')
+  ).toThrowErrorMatchingInlineSnapshot(
+    `"toHaveDisplayValue() works only with host "TextInput" elements. Passed element has type "View"."`
+  );
+});
+
+test('toHaveDisplayValue() on matching element with .not', () => {
+  render(<TextInput testID="text-input" value="test" />);
+
+  const textInput = screen.getByTestId('text-input');
+
+  expect(() => expect(textInput).not.toHaveDisplayValue('test'))
+    .toThrowErrorMatchingInlineSnapshot(`
+    "expect(element).not.toHaveDisplayValue()
+
+    Expected element not to have display value:
+      test
+    Received:
+      test"
+  `);
+});
+
+test('toHaveDisplayValue() on not matching element', () => {
+  render(<TextInput testID="text-input" value="test" />);
+
+  const textInput = screen.getByTestId('text-input');
+
+  expect(() => expect(textInput).toHaveDisplayValue('non-test'))
+    .toThrowErrorMatchingInlineSnapshot(`
+    "expect(element).toHaveDisplayValue()
+
+    Expected element to have display value:
+      non-test
+    Received:
+      test"
+  `);
+});

src/matchers/extend-expect.ts

@@ -2,8 +2,10 @@
 
 import { toBeOnTheScreen } from './to-be-on-the-screen';
 import { toBeEmptyElement } from './to-be-empty-element';
+import { toHaveDisplayValue } from './to-have-display-value';
 
 expect.extend({
   toBeOnTheScreen,
   toBeEmptyElement,
+  toHaveDisplayValue,
 });