How to fix auth/invalid-email-verified: Email verified property must be boolean in Firebase

// Check these patterns
admin.auth().createUser({
  email: "[email protected]",
  emailVerified: // <- check this value
});

admin.auth().updateUser(uid, {
  emailVerified: // <- check this value
});

// Incorrect - string value
const emailVerified = "true"; // Wrong!

// Correct - boolean conversion
const emailVerified = userData.emailVerified === "true";
// or
const emailVerified = Boolean(userData.emailVerified);
// or
const emailVerified = userData.emailVerified === true;

// Option 1: Provide default value
const userProperties = {
  email: userData.email,
  emailVerified: userData.emailVerified ?? false
};

// Option 2: Conditionally include property
const userProperties = {
  email: userData.email,
  ...(typeof userData.emailVerified === "boolean" && {
    emailVerified: userData.emailVerified
  })
};

await admin.auth().updateUser(uid, userProperties);

interface UserUpdateData {
  email?: string;
  emailVerified?: boolean;
}

function validateEmailVerified(value: any): boolean {
  if (typeof value === "boolean") {
    return value;
  }
  if (value === "true" || value === 1) {
    return true;
  }
  if (value === "false" || value === 0) {
    return false;
  }
  return false; // Default to false for invalid values
}

const userData: UserUpdateData = {
  email: "[email protected]",
  emailVerified: validateEmailVerified(rawData.emailVerified)
};

await admin.auth().updateUser(uid, userData);

// PostgreSQL with node-postgres
const result = await db.query("SELECT email_verified FROM users WHERE id = $1", [userId]);
const emailVerified = result.rows[0].email_verified; // May be string or number

// Convert to boolean
const userUpdate = {
  emailVerified: Boolean(emailVerified)
};

// MongoDB with Mongoose
const user = await User.findById(userId);
const emailVerified = user.emailVerified === true; // Ensure boolean

await admin.auth().updateUser(uid, { emailVerified });

interface FirebaseUserUpdate {
  email?: string;
  emailVerified?: boolean; // Explicitly type as boolean
  displayName?: string;
}

function updateFirebaseUser(
  uid: string,
  data: FirebaseUserUpdate
): Promise<admin.auth.UserRecord> {
  // TypeScript will catch non-boolean assignments
  return admin.auth().updateUser(uid, data);
}

// Usage - TypeScript error if wrong type
await updateFirebaseUser(uid, {
  emailVerified: true // OK
});

await updateFirebaseUser(uid, {
  emailVerified: "true" // TypeScript error!
});