[iOS][Passwords] Disabling Done button for empty password

This change disables Done button in case entered password is empty.

Bug: 1137475
Change-Id: I3e110654695c07336d6c85c01b3463d3da5c1b06
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2485493
Commit-Queue: Gauthier Ambard <gambard@chromium.org>
Reviewed-by: Gauthier Ambard <gambard@chromium.org>
Cr-Commit-Position: refs/heads/master@{#821216}

ios/chrome/browser/ui/settings/password/password_details/password_details_table_view_controller.mm

@@ -425,12 +425,7 @@ typedef NS_ENUM(NSInteger, ReauthenticationReason) {
 }
 
 - (void)tableViewItemDidChange:(TableViewTextEditItem*)tableViewItem {
-  BOOL isInputValid = YES;
-
-  if (tableViewItem == self.usernameTextItem) {
-    isInputValid = [self checkIfValidUsername];
-  }
-
+  BOOL isInputValid = [self checkIfValidUsername] & [self checkIfValidPassword];
   self.navigationItem.rightBarButtonItem.enabled = isInputValid;
 }
 
@@ -623,6 +618,17 @@ typedef NS_ENUM(NSInteger, ReauthenticationReason) {
   return !showUsernameAlreadyUsed;
 }
 
+// Checks if the password is valid and updates item accordingly.
+- (BOOL)checkIfValidPassword {
+  DCHECK(self.password.password);
+
+  BOOL passwordEmpty = [self.passwordTextItem.textFieldValue length] == 0;
+  self.passwordTextItem.hasValidText = !passwordEmpty;
+
+  [self reconfigureCellsForItems:@[ self.passwordTextItem ]];
+  return !passwordEmpty;
+}
+
 #pragma mark - Actions
 
 // Called when the user tapped on the show/hide button near password.

ios/chrome/browser/ui/settings/password/passwords_settings_egtest.mm

@@ -1417,6 +1417,14 @@ void CopyPasswordDetailWithID(int detail_id) {
   [[EarlGrey selectElementWithMatcher:PasswordDetailPassword()]
       assertWithMatcher:grey_textFieldValue(@"concrete password")];
 
+  // Check that empty password is not allowed, and done button is disabled.
+  [[EarlGrey selectElementWithMatcher:PasswordDetailPassword()]
+      performAction:grey_clearText()];
+
+  [[EarlGrey selectElementWithMatcher:NavigationBarDoneButton()]
+      assertWithMatcher:grey_allOf(grey_sufficientlyVisible(),
+                                   grey_not(grey_enabled()), nil)];
+
   [[EarlGrey selectElementWithMatcher:PasswordDetailPassword()]
       performAction:grey_replaceText(@"new password")];