Add tests for Details screen

src/screens/Details.js

@@ -9,7 +9,7 @@ import {
   deleteEntry,
 } from '../redux/modules/listings';
 
-class Details extends React.Component {
+export class Details extends React.Component {
   static navigationOptions = {
     title: 'Details',
   };

src/screens/Details.test.js

@@ -0,0 +1,69 @@
+import React from 'react';
+import { Alert } from 'react-native';
+
+import { Details } from './Details';
+import { MODIFY_ENTRY } from '../redux/modules/listings';
+
+describe('Details screen test', () => {
+  const navigationMock = {
+    state: {
+      params: {
+        id: 10,
+      },
+    },
+  };
+
+  const entryDetailsMock = {
+    name: 'malak',
+    code: '1234',
+  };
+
+  it('should render as expected', () => {
+    const wrapper = shallow(
+      <Details navigation={navigationMock} entryDetails={entryDetailsMock} />
+    );
+    expect(wrapper).toMatchSnapshot();
+  });
+
+  it('should navigate to Entry screen and pass the correct params on edit', () => {
+    const navMock = {
+      ...navigationMock,
+      navigate: jest.fn(),
+    };
+    const wrapper = shallow(
+      <Details navigation={navMock} entryDetails={entryDetailsMock} />
+    );
+    wrapper.instance().handleEditPress();
+    expect(navMock.navigate.mock.calls.length).toBe(1);
+    expect(navMock.navigate.mock.calls[0][0]).toBe('Entry');
+    expect(navMock.navigate.mock.calls[0][1]).toEqual({
+      action: MODIFY_ENTRY,
+      id: 10,
+    });
+  });
+
+  it('should delete entry and navigate back to Home on alert click', () => {
+    jest.mock('Alert', () => ({
+      alert: jest.fn(),
+    }));
+
+    const mockDelete = jest.fn();
+    const navMock = {
+      ...navigationMock,
+      popToTop: jest.fn(),
+    };
+
+    const wrapper = shallow(
+      <Details
+        navigation={navMock}
+        entryDetails={entryDetailsMock}
+        handleDeleteEntry={mockDelete}
+      />
+    );
+    wrapper.instance().handleDeletionPress();
+    Alert.alert.mock.calls[0][2][1].onPress();
+    expect(mockDelete.mock.calls.length).toBe(1);
+    expect(mockDelete.mock.calls[0][0]).toBe(10);
+    expect(navMock.popToTop.mock.calls.length).toBe(1);
+  });
+});

src/screens/__snapshots__/Details.test.js.snap

@@ -0,0 +1,10 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`Details screen test should render as expected 1`] = `
+<EntryDetail
+  code="1234"
+  name="malak"
+  onDeletePress={[Function]}
+  onEditPress={[Function]}
+/>
+`;