CodingItWrong

import React, { Component } from 'react';
import {
  View,
} from 'react-native';

export default class NewMessageForm extends Component {
  render() {
    return (
      <View>
      </View>

CodingItWrong

 import React, { Component } from 'react';
 import {
+  TextInput,
   View,
 } from 'react-native';

 export default class NewMessageForm extends Component {
   render() {
     return (
       <View>

CodingItWrong

 import React, { Component } from 'react';
 import {
+  Button,
   TextInput,
   View,
 } from 'react-native';
...
         <TextInput
           testID="messageText"
         />

CodingItWrong

import React from 'react';
import { render, fireEvent } from 'react-native-testing-library';
import NewMessageForm from '../../NewMessageForm';

describe('NewMessageForm', () => {
  describe('clicking send', () => {
    const messageText = 'Hello world';

    let getByTestId;

CodingItWrong

 export default class NewMessageForm extends Component {
+  state = { inputText: '' }
+
+  handleChangeText = (text) => {
+    this.setState({ inputText: text });
+  }
+
   render() {
+    const { inputText } = this.state;
     return (

CodingItWrong

 export default class NewMessageForm extends Component {
   state = { inputText: '' }

   handleChangeText = (text) => {
     this.setState({ inputText: text });
   }

+  handleSend = () => {
+    this.setState({ inputText: '' });
+  }

CodingItWrong

   describe('clicking send', () => {
     const messageText = 'Hello world';

+    let sendHandler;
     let getByTestId;

     beforeEach(() => {
+      sendHandler = jest.fn();

-      ({ getByTestId } = render(<NewMessageForm />));

CodingItWrong

   handleSend = () => {
+    const { inputText } = this.state;
+    const { onSend } = this.props;
+
+    onSend(inputText);
+
     this.setState({ inputText: '' });
   }

CodingItWrong

 export default class App extends Component {
+  handleSend = (newMessage) => {
+  }
+
   render() {
     return (
       <View>
-        <NewMessageForm />
+        <NewMessageForm onSend={this.handleSend} />
       </View>

CodingItWrong

 export default class App extends Component {
+  state = { messages: [] }
+
   handleSend = (newMessage) => {
+    this.setState(state => ({ messages: [newMessage, ...state.messages] }));
   }