Resolving React Native TypeError: Expected Boolean, Found Object in Android

Solution 1: Fixing Boolean TypeError in React Native with Conditional Handling

Approach: Frontend scripting in JavaScript for React Native

// This solution addresses the issue by ensuring the `disabled` prop is properly set as a boolean.
// It also uses a conditional helper function to prevent non-boolean values.

// Helper function to ensure boolean return for `disabled` prop
const isButtonDisabled = () => {
  return email.length === 0 || password.length < 7 || loading;
};

// In the main component
<TextInput
  style={styles.input}
  placeholder='Password'
  value={password}
  secureTextEntry={true}
  onChangeText={(value) => setPassword(value)}
/>

<TouchableOpacity
  style={[
    { backgroundColor: "black", borderRadius: 5 },
    isButtonDisabled() && { opacity: 0.5 }
  ]}
  disabled={isButtonDisabled()}
  onPress={() => signInWithEmail()}
>
  <Text style={{ color: "white", padding: 10, textAlign: "center" }}>Login</Text>
</TouchableOpacity>

Solution 2: Ensuring Boolean Type Consistency with TypeScript Type Checking

Approach: Frontend scripting with TypeScript for React Native

// Adding TypeScript to enforce stronger typing and catch issues early.
// In this approach, we declare the expected types explicitly for better consistency.

// Import necessary TypeScript types
import React, { useState } from 'react';
import { TextInput, TouchableOpacity, Text, StyleSheet } from 'react-native';

type AuthProps = {
  email: string;
  password: string;
  loading: boolean;
};

const isButtonDisabled = (email: string, password: string, loading: boolean): boolean => {
  return email.length === 0 || password.length < 7 || loading;
};

const AuthScreen: React.FC = () => {
  const [email, setEmail] = useState<string>('');
  const [password, setPassword] = useState<string>('');
  const [loading, setLoading] = useState<boolean>(false);

  return (
    <>
      <TextInput
        style={styles.input}
        placeholder='Password'
        value={password}
        secureTextEntry={true}
        onChangeText={(value: string) => setPassword(value)}
      />

      <TouchableOpacity
        style={[
          { backgroundColor: "black", borderRadius: 5 },
          isButtonDisabled(email, password, loading) && { opacity: 0.5 }
        ]}
        disabled={isButtonDisabled(email, password, loading)}
        onPress={() => signInWithEmail()}
      >
        <Text style={{ color: "white", padding: 10, textAlign: "center" }}>Login</Text>
      </TouchableOpacity>
    </>
  );
};

const styles = StyleSheet.create({
  input: {
    borderColor: '#ddd',
    borderWidth: 1,
    padding: 10,
    marginBottom: 10
  }
});

Solution 3: Backend Verification with Supabase Authentication API

Approach: Backend API check with Node.js for validation with Supabase

// In this solution, we add backend verification to ensure the frontend error is handled correctly.
// This involves creating an API endpoint to validate user credentials before processing the login.

const express = require('express');
const supabase = require('@supabase/supabase-js');
const app = express();

// Initialize Supabase client
const supabaseUrl = 'https://your-supabase-url';
const supabaseKey = 'your-supabase-key';
const client = supabase.createClient(supabaseUrl, supabaseKey);

app.use(express.json());

// Route for login verification
app.post('/api/login', async (req, res) => {
  const { email, password } = req.body;
  if (!email || !password) {
    return res.status(400).json({ error: 'Email and password required' });
  }
  const { user, error } = await client.auth.signIn({ email, password });
  if (error) {
    return res.status(401).json({ error: 'Invalid credentials' });
  }
  res.json({ message: 'Login successful', user });
});

app.listen(3000, () => console.log('Server running on http://localhost:3000'));

Common Questions on Android TypeErrors in React Native Authentication

1. Why do I get a TypeError when using disabled with TouchableOpacity?
2. This TypeError usually happens because disabled expects a boolean value, but it may receive an object if conditions are not strictly returning true or false.
3. How can I ensure disabled only receives a boolean?
4. Wrap the conditions in a helper function that evaluates them and returns true or false, such as isButtonDisabled(), to ensure the disabled prop is always a boolean.
5. What’s the role of secureTextEntry in TextInput?
6. secureTextEntry is used to mask input, which is essential for password fields. It prevents sensitive information from being displayed on the screen.
7. Can using TypeScript prevent TypeErrors in React Native?
8. Yes, TypeScript enforces strict typing, which helps prevent TypeErrors by ensuring each variable, like loading or email, has a defined type, reducing runtime issues.
9. How does backend validation help with TypeErrors in React Native?
10. By using a backend, like Supabase, you can offload some validation checks. This ensures that invalid data never reaches the client side, reducing TypeErrors and improving security.
11. Why does the error occur when I add special characters in my password?
12. This can happen if the password contains unexpected types or formats that the frontend cannot interpret properly, triggering a TypeError. Using strong type checks helps prevent this.
13. What are the benefits of using auth.signIn() in Supabase?
14. The auth.signIn() method allows you to securely authenticate users with email and password, managing validation on the server to keep the client error-free.
15. How does onChangeText improve data handling in TextInput?
16. The onChangeText prop captures real-time input, updating states instantly to ensure accuracy before the user submits their credentials.
17. What is opacity used for in TouchableOpacity?
18. opacity visually indicates whether the button is disabled by lowering its transparency, providing feedback to users when conditions aren’t met.
19. Is it possible to avoid TypeErrors without TypeScript?
20. Yes, by using helper functions that enforce booleans and validating input consistently, you can reduce TypeErrors without TypeScript, although TypeScript does provide extra type safety.

Wrapping Up with Best Practices

Preventing TypeErrors in React Native requires careful attention to data types, especially on Android. By ensuring boolean values in properties like disabled and adding backend checks, you create a smoother, more reliable authentication flow. These methods reduce the likelihood of unexpected crashes. 🛠️

Utilizing TypeScript and helper functions for type consistency, as well as backend validation through Supabase, adds layers of security and stability. With these strategies, developers can confidently handle authentication flows and improve app reliability across devices. 👍