Improved UI and compliance with api endpoint restrictions

src/validation/auth.js

@@ -61,20 +61,36 @@ function isDisposableEmail(email) {
   );
 }
 
-export function validateRegistration({ name, username, email, password }) {
-  const trimmedName = name.trim();
-  const trimmedUsername = username.trim();
-  const normalizedEmail = email.trim().toLowerCase();
+function hasControlCharacter(value) {
+  return [...value].some((character) => {
+    const code = character.charCodeAt(0);
+    return code <= 0x1f || code === 0x7f;
+  });
+}
 
+function validateName(name) {
+  const trimmedName = name.trim();
+  if (hasControlCharacter(name)) {
+    return "Input contains unsupported control characters.";
+  }
   if (trimmedName.length < 1 || trimmedName.length > 100) {
     return "Name must be between 1 and 100 characters.";
   }
+  return null;
+}
 
-  if (trimmedUsername.length < 1 || trimmedUsername.length > 50 || /\s/.test(trimmedUsername)) {
+function validateUsername(username) {
+  const trimmedUsername = username.trim();
+  if (hasControlCharacter(username) || trimmedUsername.length < 1 || trimmedUsername.length > 50 || /\s/.test(trimmedUsername)) {
     return "Username must be between 1 and 50 characters and cannot contain whitespace.";
   }
+  return null;
+}
 
+function validateEmail(email, { checkDisposable = false } = {}) {
+  const normalizedEmail = email.trim().toLowerCase();
   if (
+    hasControlCharacter(email) ||
     normalizedEmail.length < 1 ||
     normalizedEmail.length > 254 ||
     /\s/.test(normalizedEmail) ||
@@ -82,8 +98,14 @@ export function validateRegistration({ name, username, email, password }) {
   ) {
     return "Enter a valid email address without whitespace.";
   }
+  if (checkDisposable && isDisposableEmail(normalizedEmail)) {
+    return "Disposable or temporary email addresses are not allowed.";
+  }
+  return null;
+}
 
-  if (password.length < 1 || password.length > 128) {
+function validatePassword(password, username, email) {
+  if (hasControlCharacter(password) || password.length < 1 || password.length > 128) {
     return "Password must be between 1 and 128 characters.";
   }
 
@@ -96,9 +118,14 @@ export function validateRegistration({ name, username, email, password }) {
   }
 
   const passwordForComparison = password.toLowerCase();
-  const { localPart } = getEmailParts(normalizedEmail);
+  const trimmedUsername = username.trim();
+  const normalizedEmail = email.trim().toLowerCase();
+  const localPart = EMAIL_PATTERN.test(normalizedEmail) ? getEmailParts(normalizedEmail).localPart : "";
 
-  if (passwordForComparison.includes(trimmedUsername.toLowerCase()) || passwordForComparison.includes(localPart.toLowerCase())) {
+  if (
+    (trimmedUsername && passwordForComparison.includes(trimmedUsername.toLowerCase())) ||
+    (localPart && passwordForComparison.includes(localPart.toLowerCase()))
+  ) {
     return "Password cannot contain your username or email address.";
   }
 
@@ -110,27 +137,42 @@ export function validateRegistration({ name, username, email, password }) {
     return "Password cannot contain repeated or sequential character patterns.";
   }
 
-  if (isDisposableEmail(normalizedEmail)) {
-    return "Disposable or temporary email addresses are not allowed.";
-  }
-
   return null;
 }
 
-export function validateLogin({ email, password }) {
-  const normalizedEmail = email.trim().toLowerCase();
-
-  if (normalizedEmail.length < 1 || normalizedEmail.length > 254 || /\s/.test(normalizedEmail) || !EMAIL_PATTERN.test(normalizedEmail)) {
-    return "Enter a valid email address without whitespace.";
-  }
+export function getRegistrationFieldErrors(form) {
+  return {
+    name: validateName(form.name),
+    username: validateUsername(form.username),
+    email: validateEmail(form.email, { checkDisposable: true }),
+    password: validatePassword(form.password, form.username, form.email),
+  };
+}
 
+function validateLoginPassword(password) {
   if (password.length < 1 || password.length > 128) {
     return "Password must be between 1 and 128 characters.";
   }
-
   return null;
 }
 
+export function getLoginFieldErrors(form) {
+  return {
+    email: validateEmail(form.email),
+    password: validateLoginPassword(form.password),
+  };
+}
+
+export function validateRegistration(form) {
+  const errors = getRegistrationFieldErrors(form);
+  return errors.name || errors.username || errors.email || errors.password || null;
+}
+
+export function validateLogin({ email, password }) {
+  const errors = getLoginFieldErrors({ email, password });
+  return errors.email || errors.password || null;
+}
+
 export function normalizeRegistrationData({ name, username, email, password }) {
   return {
     name: name.trim(),
@@ -148,8 +190,5 @@ export function normalizeLoginData({ email, password }) {
 }
 
 export function isControlCharacterPresent(value) {
-  return [...value].some((character) => {
-    const code = character.charCodeAt(0);
-    return code <= 0x1f || code === 0x7f;
-  });
+  return hasControlCharacter(value);
 }