[PR] Moves validation logic from the coordinators to the mediators objects.

Cq-Include-Trybots: master.tryserver.chromium.mac:ios-simulator-cronet
Change-Id: Ie818accb5c56a472ce424b442d13ee0a1dfa3a95
Reviewed-on: https://chromium-review.googlesource.com/741092Reviewed-by: Marc-Antoine Courteau <macourteau@chromium.org>
Commit-Queue: Moe Ahmadi <mahmadi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#512586}

ios/chrome/browser/ui/payments/BUILD.gn

@@ -110,6 +110,7 @@ source_set("payments_ui") {
     "payment_request_edit_view_controller.mm",
     "payment_request_edit_view_controller_actions.h",
     "payment_request_edit_view_controller_data_source.h",
+    "payment_request_edit_view_controller_validator.h",
     "payment_request_editor_field.h",
     "payment_request_editor_field.mm",
     "payment_request_error_view_controller.h",

ios/chrome/browser/ui/payments/address_edit_coordinator.h

@@ -40,7 +40,6 @@ class PaymentRequest;
 // provided in the initializer.
 @interface AddressEditCoordinator
     : ChromeCoordinator<PaymentRequestEditViewControllerDelegate,
-                        PaymentRequestEditViewControllerValidator,
                         CountrySelectionCoordinatorDelegate>
 
 // The address to be edited, if any. This pointer is not owned by this class

ios/chrome/browser/ui/payments/address_edit_coordinator.mm

@@ -11,10 +11,8 @@
 #include "components/autofill/core/browser/autofill_profile.h"
 #include "components/autofill/core/browser/autofill_type.h"
 #include "components/autofill/core/browser/personal_data_manager.h"
-#include "components/autofill/core/browser/validation.h"
 #include "components/autofill/core/common/autofill_constants.h"
 #include "components/payments/core/payments_profile_comparator.h"
-#include "components/strings/grit/components_strings.h"
 #include "ios/chrome/browser/payments/payment_request.h"
 #import "ios/chrome/browser/ui/autofill/autofill_ui_type_util.h"
 #import "ios/chrome/browser/ui/payments/address_edit_mediator.h"
@@ -58,12 +56,12 @@ using ::AutofillTypeFromAutofillUIType;
 - (void)start {
   self.editViewController = [[PaymentRequestEditViewController alloc] init];
   [self.editViewController setDelegate:self];
-  [self.editViewController setValidatorDelegate:self];
   self.mediator =
       [[AddressEditMediator alloc] initWithPaymentRequest:self.paymentRequest
                                                   address:self.address];
   [self.mediator setConsumer:self.editViewController];
   [self.editViewController setDataSource:self.mediator];
+  [self.editViewController setValidatorDelegate:self.mediator];
   [self.editViewController loadModel];
 
   self.viewController = [[PaymentRequestNavigationController alloc]
@@ -88,33 +86,6 @@ using ::AutofillTypeFromAutofillUIType;
   self.viewController = nil;
 }
 
-#pragma mark - PaymentRequestEditViewControllerValidator
-
-- (NSString*)paymentRequestEditViewController:
-                 (PaymentRequestEditViewController*)controller
-                                validateField:(EditorField*)field {
-  if (field.value.length) {
-    switch (field.autofillUIType) {
-      case AutofillUITypeProfileHomePhoneWholeNumber: {
-        const std::string selectedCountryCode =
-            base::SysNSStringToUTF8(self.mediator.selectedCountryCode);
-        if (!autofill::IsValidPhoneNumber(base::SysNSStringToUTF16(field.value),
-                                          selectedCountryCode)) {
-          return l10n_util::GetNSString(
-              IDS_PAYMENTS_PHONE_INVALID_VALIDATION_MESSAGE);
-        }
-        break;
-      }
-      default:
-        break;
-    }
-  } else if (field.isRequired) {
-    return l10n_util::GetNSString(
-        IDS_PAYMENTS_FIELD_REQUIRED_VALIDATION_MESSAGE);
-  }
-  return nil;
-}
-
 #pragma mark - PaymentRequestEditViewControllerDelegate
 
 - (void)paymentRequestEditViewController:

ios/chrome/browser/ui/payments/address_edit_mediator.h

@@ -6,6 +6,7 @@
 #define IOS_CHROME_BROWSER_UI_PAYMENTS_ADDRESS_EDIT_MEDIATOR_H_
 
 #import "ios/chrome/browser/ui/payments/payment_request_edit_view_controller_data_source.h"
+#import "ios/chrome/browser/ui/payments/payment_request_edit_view_controller_validator.h"
 #import "ios/chrome/browser/ui/payments/region_data_loader.h"
 
 @protocol PaymentRequestEditConsumer;
@@ -21,6 +22,7 @@ class PaymentRequest;
 // Serves as data source for AddressEditViewController.
 @interface AddressEditMediator
     : NSObject<PaymentRequestEditViewControllerDataSource,
+               PaymentRequestEditViewControllerValidator,
                RegionDataLoaderConsumer>
 
 // The consumer for this object. This can change during the lifetime of this

ios/chrome/browser/ui/payments/address_edit_mediator.mm

@@ -23,6 +23,7 @@
 #include "components/autofill/core/browser/field_types.h"
 #include "components/autofill/core/browser/personal_data_manager.h"
 #include "components/autofill/core/browser/phone_number_i18n.h"
+#include "components/autofill/core/browser/validation.h"
 #include "components/payments/core/payment_request_data_util.h"
 #include "components/strings/grit/components_strings.h"
 #include "ios/chrome/browser/payments/payment_request.h"
@@ -181,6 +182,33 @@ NSString* NormalizeRegionName(NSString* region, NSArray<RegionData*>* regions) {
   return nil;
 }
 
+#pragma mark - PaymentRequestEditViewControllerValidator
+
+- (NSString*)paymentRequestEditViewController:
+                 (PaymentRequestEditViewController*)controller
+                                validateField:(EditorField*)field {
+  if (field.value.length) {
+    switch (field.autofillUIType) {
+      case AutofillUITypeProfileHomePhoneWholeNumber: {
+        const std::string selectedCountryCode =
+            base::SysNSStringToUTF8(self.selectedCountryCode);
+        if (!autofill::IsValidPhoneNumber(base::SysNSStringToUTF16(field.value),
+                                          selectedCountryCode)) {
+          return l10n_util::GetNSString(
+              IDS_PAYMENTS_PHONE_INVALID_VALIDATION_MESSAGE);
+        }
+        break;
+      }
+      default:
+        break;
+    }
+  } else if (field.isRequired) {
+    return l10n_util::GetNSString(
+        IDS_PAYMENTS_FIELD_REQUIRED_VALIDATION_MESSAGE);
+  }
+  return nil;
+}
+
 #pragma mark - RegionDataLoaderConsumer
 
 - (void)regionDataLoaderDidSucceedWithRegions:(NSArray<RegionData*>*)regions {

ios/chrome/browser/ui/payments/address_edit_mediator_unittest.mm

@@ -8,6 +8,8 @@
 #include "components/autofill/core/browser/autofill_test_utils.h"
 #include "components/strings/grit/components_strings.h"
 #import "ios/chrome/browser/payments/payment_request_unittest_base.h"
+#import "ios/chrome/browser/ui/autofill/autofill_ui_type.h"
+#import "ios/chrome/browser/ui/payments/payment_request_editor_field.h"
 #include "testing/platform_test.h"
 #include "third_party/ocmock/gtest_support.h"
 #include "ui/base/l10n/l10n_util.h"
@@ -28,6 +30,67 @@ class PaymentRequestAddressEditMediatorTest : public PaymentRequestUnitTestBase,
   void TearDown() override { PaymentRequestUnitTestBase::TearDown(); }
 };
 
+// Tests that no validation error should be expected if validating an empty
+// field that is not required.
+TEST_F(PaymentRequestAddressEditMediatorTest, ValidateEmptyField) {
+  AddressEditMediator* mediator =
+      [[AddressEditMediator alloc] initWithPaymentRequest:payment_request()
+                                                  address:nil];
+
+  EditorField* field = [[EditorField alloc]
+      initWithAutofillUIType:AutofillUITypeProfileHomePhoneWholeNumber
+                   fieldType:EditorFieldTypeTextField
+                       label:@""
+                       value:@""
+                    required:NO];
+  NSString* validationError =
+      [mediator paymentRequestEditViewController:nil
+                                   validateField:(EditorField*)field];
+  EXPECT_TRUE(!validationError);
+}
+
+// Tests that the appropriate validation error should be expected if validating
+// an empty field that is required.
+TEST_F(PaymentRequestAddressEditMediatorTest, ValidateEmptyRequiredField) {
+  AddressEditMediator* mediator =
+      [[AddressEditMediator alloc] initWithPaymentRequest:payment_request()
+                                                  address:nil];
+
+  EditorField* field = [[EditorField alloc]
+      initWithAutofillUIType:AutofillUITypeProfileHomePhoneWholeNumber
+                   fieldType:EditorFieldTypeTextField
+                       label:@""
+                       value:@""
+                    required:YES];
+  NSString* validationError =
+      [mediator paymentRequestEditViewController:nil
+                                   validateField:(EditorField*)field];
+  EXPECT_TRUE([validationError
+      isEqualToString:l10n_util::GetNSString(
+                          IDS_PAYMENTS_FIELD_REQUIRED_VALIDATION_MESSAGE)]);
+}
+
+// Tests that the appropriate validation error should be expected if validating
+// a field with an invalid value.
+TEST_F(PaymentRequestAddressEditMediatorTest, ValidateFieldInvalidValue) {
+  AddressEditMediator* mediator =
+      [[AddressEditMediator alloc] initWithPaymentRequest:payment_request()
+                                                  address:nil];
+
+  EditorField* field = [[EditorField alloc]
+      initWithAutofillUIType:AutofillUITypeProfileHomePhoneWholeNumber
+                   fieldType:EditorFieldTypeTextField
+                       label:@""
+                       value:@"1506853121"  // Missing one last digit.
+                    required:YES];
+  NSString* validationError =
+      [mediator paymentRequestEditViewController:nil
+                                   validateField:(EditorField*)field];
+  EXPECT_TRUE([validationError
+      isEqualToString:l10n_util::GetNSString(
+                          IDS_PAYMENTS_PHONE_INVALID_VALIDATION_MESSAGE)]);
+}
+
 // Tests that the editor's title is correct in various situations.
 TEST_F(PaymentRequestAddressEditMediatorTest, Title) {
   // No address, so the title should ask to add an address.

ios/chrome/browser/ui/payments/contact_info_edit_coordinator.h

@@ -39,8 +39,7 @@ class PaymentRequest;
 // controller. This view controller will be presented by the view controller
 // provided in the initializer.
 @interface ContactInfoEditCoordinator
-    : ChromeCoordinator<PaymentRequestEditViewControllerDelegate,
-                        PaymentRequestEditViewControllerValidator>
+    : ChromeCoordinator<PaymentRequestEditViewControllerDelegate>
 
 // The profile to be edited, if any. This pointer is not owned by this class
 // and should outlive it.

ios/chrome/browser/ui/payments/contact_info_edit_coordinator.mm

@@ -14,7 +14,6 @@
 #include "components/autofill/core/browser/validation.h"
 #include "components/autofill/core/common/autofill_constants.h"
 #include "components/payments/core/payments_profile_comparator.h"
-#include "components/strings/grit/components_strings.h"
 #include "ios/chrome/browser/payments/payment_request.h"
 #import "ios/chrome/browser/ui/autofill/autofill_ui_type_util.h"
 #import "ios/chrome/browser/ui/payments/contact_info_edit_mediator.h"
@@ -53,12 +52,12 @@ using ::AutofillTypeFromAutofillUIType;
 - (void)start {
   self.editViewController = [[PaymentRequestEditViewController alloc] init];
   [self.editViewController setDelegate:self];
-  [self.editViewController setValidatorDelegate:self];
   self.mediator = [[ContactInfoEditMediator alloc]
       initWithPaymentRequest:self.paymentRequest
                      profile:self.profile];
   [self.mediator setConsumer:self.editViewController];
   [self.editViewController setDataSource:self.mediator];
+  [self.editViewController setValidatorDelegate:self.mediator];
   [self.editViewController loadModel];
 
   self.viewController = [[PaymentRequestNavigationController alloc]
@@ -81,42 +80,6 @@ using ::AutofillTypeFromAutofillUIType;
   self.viewController = nil;
 }
 
-#pragma mark - PaymentRequestEditViewControllerValidator
-
-- (NSString*)paymentRequestEditViewController:
-                 (PaymentRequestEditViewController*)controller
-                                validateField:(EditorField*)field {
-  if (field.value.length) {
-    switch (field.autofillUIType) {
-      case AutofillUITypeProfileHomePhoneWholeNumber: {
-        const std::string countryCode =
-            autofill::AutofillCountry::CountryCodeForLocale(
-                self.paymentRequest->GetApplicationLocale());
-        if (!autofill::IsValidPhoneNumber(base::SysNSStringToUTF16(field.value),
-                                          countryCode)) {
-          return l10n_util::GetNSString(
-              IDS_PAYMENTS_PHONE_INVALID_VALIDATION_MESSAGE);
-        }
-        break;
-      }
-      case AutofillUITypeProfileEmailAddress: {
-        if (!autofill::IsValidEmailAddress(
-                base::SysNSStringToUTF16(field.value))) {
-          return l10n_util::GetNSString(
-              IDS_PAYMENTS_EMAIL_INVALID_VALIDATION_MESSAGE);
-        }
-        break;
-      }
-      default:
-        break;
-    }
-  } else if (field.isRequired) {
-    return l10n_util::GetNSString(
-        IDS_PAYMENTS_FIELD_REQUIRED_VALIDATION_MESSAGE);
-  }
-  return nil;
-}
-
 #pragma mark - PaymentRequestEditViewControllerDelegate
 
 - (void)paymentRequestEditViewController:

ios/chrome/browser/ui/payments/contact_info_edit_mediator.h

@@ -8,6 +8,7 @@
 #import <Foundation/Foundation.h>
 
 #import "ios/chrome/browser/ui/payments/payment_request_edit_view_controller_data_source.h"
+#import "ios/chrome/browser/ui/payments/payment_request_edit_view_controller_validator.h"
 
 @protocol PaymentRequestEditConsumer;
 
@@ -21,7 +22,8 @@ class PaymentRequest;
 
 // Serves as data source for AddressEditViewController.
 @interface ContactInfoEditMediator
-    : NSObject<PaymentRequestEditViewControllerDataSource>
+    : NSObject<PaymentRequestEditViewControllerDataSource,
+               PaymentRequestEditViewControllerValidator>
 
 // The consumer for this object. This can change during the lifetime of this
 // object and may be nil.

ios/chrome/browser/ui/payments/contact_info_edit_mediator.mm

@@ -11,6 +11,7 @@
 #include "components/autofill/core/browser/autofill_type.h"
 #include "components/autofill/core/browser/field_types.h"
 #include "components/autofill/core/browser/phone_number_i18n.h"
+#include "components/autofill/core/browser/validation.h"
 #include "components/payments/core/payment_request_data_util.h"
 #include "components/strings/grit/components_strings.h"
 #include "ios/chrome/browser/payments/payment_request.h"
@@ -104,6 +105,42 @@
   return nil;
 }
 
+#pragma mark - PaymentRequestEditViewControllerValidator
+
+- (NSString*)paymentRequestEditViewController:
+                 (PaymentRequestEditViewController*)controller
+                                validateField:(EditorField*)field {
+  if (field.value.length) {
+    switch (field.autofillUIType) {
+      case AutofillUITypeProfileHomePhoneWholeNumber: {
+        const std::string countryCode =
+            autofill::AutofillCountry::CountryCodeForLocale(
+                self.paymentRequest->GetApplicationLocale());
+        if (!autofill::IsValidPhoneNumber(base::SysNSStringToUTF16(field.value),
+                                          countryCode)) {
+          return l10n_util::GetNSString(
+              IDS_PAYMENTS_PHONE_INVALID_VALIDATION_MESSAGE);
+        }
+        break;
+      }
+      case AutofillUITypeProfileEmailAddress: {
+        if (!autofill::IsValidEmailAddress(
+                base::SysNSStringToUTF16(field.value))) {
+          return l10n_util::GetNSString(
+              IDS_PAYMENTS_EMAIL_INVALID_VALIDATION_MESSAGE);
+        }
+        break;
+      }
+      default:
+        break;
+    }
+  } else if (field.isRequired) {
+    return l10n_util::GetNSString(
+        IDS_PAYMENTS_FIELD_REQUIRED_VALIDATION_MESSAGE);
+  }
+  return nil;
+}
+
 #pragma mark - Helper methods
 
 // Creates and returns an array of editor fields.

ios/chrome/browser/ui/payments/contact_info_edit_mediator_unittest.mm

@@ -10,6 +10,7 @@
 #include "components/strings/grit/components_strings.h"
 #include "ios/chrome/browser/payments/payment_request_test_util.h"
 #import "ios/chrome/browser/payments/payment_request_unittest_base.h"
+#import "ios/chrome/browser/ui/autofill/autofill_ui_type.h"
 #import "ios/chrome/browser/ui/autofill/autofill_ui_type_util.h"
 #import "ios/chrome/browser/ui/payments/payment_request_edit_consumer.h"
 #import "ios/chrome/browser/ui/payments/payment_request_editor_field.h"
@@ -197,6 +198,80 @@ TEST_F(PaymentRequestContactInfoEditMediatorTest, TestFieldsRequestPhoneEmail) {
   EXPECT_OCMOCK_VERIFY(consumer);
 }
 
+// Tests that no validation error should be expected if validating an empty
+// field that is not required.
+TEST_F(PaymentRequestContactInfoEditMediatorTest, ValidateEmptyField) {
+  ContactInfoEditMediator* mediator =
+      [[ContactInfoEditMediator alloc] initWithPaymentRequest:payment_request()
+                                                      profile:nil];
+
+  EditorField* field = [[EditorField alloc]
+      initWithAutofillUIType:AutofillUITypeProfileHomePhoneWholeNumber
+                   fieldType:EditorFieldTypeTextField
+                       label:@""
+                       value:@""
+                    required:NO];
+  NSString* validationError =
+      [mediator paymentRequestEditViewController:nil
+                                   validateField:(EditorField*)field];
+  EXPECT_TRUE(!validationError);
+}
+
+// Tests that the appropriate validation error should be expected if validating
+// an empty field that is required.
+TEST_F(PaymentRequestContactInfoEditMediatorTest, ValidateEmptyRequiredField) {
+  ContactInfoEditMediator* mediator =
+      [[ContactInfoEditMediator alloc] initWithPaymentRequest:payment_request()
+                                                      profile:nil];
+
+  EditorField* field = [[EditorField alloc]
+      initWithAutofillUIType:AutofillUITypeProfileHomePhoneWholeNumber
+                   fieldType:EditorFieldTypeTextField
+                       label:@""
+                       value:@""
+                    required:YES];
+  NSString* validationError =
+      [mediator paymentRequestEditViewController:nil
+                                   validateField:(EditorField*)field];
+  EXPECT_TRUE([validationError
+      isEqualToString:l10n_util::GetNSString(
+                          IDS_PAYMENTS_FIELD_REQUIRED_VALIDATION_MESSAGE)]);
+}
+
+// Tests that the appropriate validation error should be expected if validating
+// a field with an invalid value.
+TEST_F(PaymentRequestContactInfoEditMediatorTest, ValidateFieldInvalidValue) {
+  ContactInfoEditMediator* mediator =
+      [[ContactInfoEditMediator alloc] initWithPaymentRequest:payment_request()
+                                                      profile:nil];
+
+  EditorField* field = [[EditorField alloc]
+      initWithAutofillUIType:AutofillUITypeProfileHomePhoneWholeNumber
+                   fieldType:EditorFieldTypeTextField
+                       label:@""
+                       value:@"1506853121"  // Missing one last digit.
+                    required:YES];
+  NSString* validationError =
+      [mediator paymentRequestEditViewController:nil
+                                   validateField:(EditorField*)field];
+  EXPECT_TRUE([validationError
+      isEqualToString:l10n_util::GetNSString(
+                          IDS_PAYMENTS_PHONE_INVALID_VALIDATION_MESSAGE)]);
+
+  field = [[EditorField alloc]
+      initWithAutofillUIType:AutofillUITypeProfileEmailAddress
+                   fieldType:EditorFieldTypeTextField
+                       label:@""
+                       value:@"example.com"  // Invalid email address.
+                    required:YES];
+  validationError =
+      [mediator paymentRequestEditViewController:nil
+                                   validateField:(EditorField*)field];
+  EXPECT_TRUE([validationError
+      isEqualToString:l10n_util::GetNSString(
+                          IDS_PAYMENTS_EMAIL_INVALID_VALIDATION_MESSAGE)]);
+}
+
 // Tests that the editor's title is correct in various situations.
 TEST_F(PaymentRequestContactInfoEditMediatorTest, Title) {
   // No profile, so the title should ask to add contact details.

ios/chrome/browser/ui/payments/credit_card_edit_coordinator.h

@@ -44,8 +44,7 @@ class PaymentRequest;
 @interface CreditCardEditCoordinator
     : ChromeCoordinator<AddressEditCoordinatorDelegate,
                         BillingAddressSelectionCoordinatorDelegate,
-                        PaymentRequestEditViewControllerDelegate,
-                        PaymentRequestEditViewControllerValidator>
+                        PaymentRequestEditViewControllerDelegate>
 
 // The payment method to be edited, if any. This pointer is not owned by this
 // class and should outlive it.

ios/chrome/browser/ui/payments/credit_card_edit_coordinator.mm

@@ -11,13 +11,10 @@
 #include "components/autofill/core/browser/autofill_type.h"
 #include "components/autofill/core/browser/credit_card.h"
 #include "components/autofill/core/browser/personal_data_manager.h"
-#include "components/autofill/core/browser/validation.h"
-#include "components/autofill/core/common/autofill_clock.h"
 #include "components/autofill/core/common/autofill_constants.h"
 #import "components/autofill/ios/browser/credit_card_util.h"
 #include "components/payments/core/autofill_payment_instrument.h"
 #include "components/payments/core/payment_instrument.h"
-#include "components/strings/grit/components_strings.h"
 #include "ios/chrome/browser/payments/payment_request.h"
 #import "ios/chrome/browser/ui/autofill/autofill_ui_type_util.h"
 #import "ios/chrome/browser/ui/payments/credit_card_edit_mediator.h"
@@ -29,46 +26,6 @@
 #error "This file requires ARC support."
 #endif
 
-namespace {
-using ::AutofillUITypeFromAutofillType;
-using ::AutofillTypeFromAutofillUIType;
-
-// Returns true if |card_number| is a supported card type and a valid credit
-// card number and no other credit card with the same number exists.
-// |error_message| can't be null and will be filled with the appropriate error
-// message iff the return value is false.
-bool IsValidCreditCardNumber(const base::string16& card_number,
-                             payments::PaymentRequest* payment_request,
-                             const autofill::CreditCard* credit_card_to_edit,
-                             base::string16* error_message) {
-  std::set<std::string> supported_card_networks(
-      payment_request->supported_card_networks().begin(),
-      payment_request->supported_card_networks().end());
-  if (!::autofill::IsValidCreditCardNumberForBasicCardNetworks(
-          card_number, supported_card_networks, error_message)) {
-    return false;
-  }
-
-  // Check if another credit card has already been created with this number.
-  // TODO(crbug.com/725604): the UI should offer to load / update the existing
-  // credit card info.
-  autofill::CreditCard* existing_card =
-      payment_request->GetPersonalDataManager()->GetCreditCardByNumber(
-          base::UTF16ToASCII(card_number));
-  // If a card exists, it could be the one currently being edited.
-  if (!existing_card || (credit_card_to_edit && credit_card_to_edit->guid() ==
-                                                    existing_card->guid())) {
-    return true;
-  }
-  if (error_message) {
-    *error_message = l10n_util::GetStringUTF16(
-        IDS_PAYMENTS_VALIDATION_ALREADY_USED_CREDIT_CARD_NUMBER);
-  }
-  return false;
-}
-
-}  // namespace
-
 @interface CreditCardEditCoordinator ()
 
 @property(nonatomic, assign) autofill::CreditCard* creditCard;
@@ -105,12 +62,12 @@ bool IsValidCreditCardNumber(const base::string16& card_number,
 
   _editViewController = [[PaymentRequestEditViewController alloc] init];
   [_editViewController setDelegate:self];
-  [_editViewController setValidatorDelegate:self];
   _mediator = [[CreditCardEditViewControllerMediator alloc]
       initWithPaymentRequest:_paymentRequest
                   creditCard:_creditCard];
   [_mediator setConsumer:_editViewController];
   [_editViewController setDataSource:_mediator];
+  [_editViewController setValidatorDelegate:_mediator];
   [_editViewController loadModel];
 
   self.viewController = [[PaymentRequestNavigationController alloc]
@@ -137,41 +94,6 @@ bool IsValidCreditCardNumber(const base::string16& card_number,
   self.viewController = nil;
 }
 
-#pragma mark - PaymentRequestEditViewControllerValidator
-
-- (NSString*)paymentRequestEditViewController:
-                 (PaymentRequestEditViewController*)controller
-                                validateField:(EditorField*)field {
-  if (field.value.length) {
-    base::string16 errorMessage;
-    base::string16 valueString = base::SysNSStringToUTF16(field.value);
-    if (field.autofillUIType == AutofillUITypeCreditCardNumber) {
-      ::IsValidCreditCardNumber(valueString, _paymentRequest, _creditCard,
-                                &errorMessage);
-    } else if (field.autofillUIType == AutofillUITypeCreditCardExpDate) {
-      NSArray<NSString*>* fieldComponents =
-          [field.value componentsSeparatedByString:@" / "];
-      int expMonth = [fieldComponents[0] intValue];
-      int expYear = [fieldComponents[1] intValue];
-      if (!autofill::IsValidCreditCardExpirationDate(
-              expYear, expMonth, autofill::AutofillClock::Now())) {
-        errorMessage = l10n_util::GetStringUTF16(
-            IDS_PAYMENTS_VALIDATION_INVALID_CREDIT_CARD_EXPIRED);
-      }
-    } else if (field.autofillUIType != AutofillUITypeCreditCardBillingAddress &&
-               field.autofillUIType != AutofillUITypeCreditCardSaveToChrome) {
-      autofill::IsValidForType(
-          valueString, AutofillTypeFromAutofillUIType(field.autofillUIType),
-          &errorMessage);
-    }
-    return !errorMessage.empty() ? base::SysUTF16ToNSString(errorMessage) : nil;
-  } else if (field.isRequired) {
-    return l10n_util::GetNSString(
-        IDS_PAYMENTS_FIELD_REQUIRED_VALIDATION_MESSAGE);
-  }
-  return nil;
-}
-
 #pragma mark - PaymentRequestEditViewControllerDelegate
 
 - (void)paymentRequestEditViewController:

ios/chrome/browser/ui/payments/credit_card_edit_mediator.h

@@ -6,6 +6,7 @@
 #define IOS_CHROME_BROWSER_UI_PAYMENTS_CREDIT_CARD_EDIT_MEDIATOR_H_
 
 #import "ios/chrome/browser/ui/payments/payment_request_edit_view_controller_data_source.h"
+#import "ios/chrome/browser/ui/payments/payment_request_edit_view_controller_validator.h"
 
 @protocol PaymentRequestEditConsumer;
 
@@ -20,7 +21,8 @@ class PaymentRequest;
 
 // Serves as data source for CreditCardEditViewController.
 @interface CreditCardEditViewControllerMediator
-    : NSObject<PaymentRequestEditViewControllerDataSource>
+    : NSObject<PaymentRequestEditViewControllerDataSource,
+               PaymentRequestEditViewControllerValidator>
 
 // The consumer for this object. This can change during the lifetime of this
 // object and may be nil.

ios/chrome/browser/ui/payments/credit_card_edit_mediator.mm

@@ -5,11 +5,13 @@
 #import "ios/chrome/browser/ui/payments/credit_card_edit_mediator.h"
 
 #include "base/strings/sys_string_conversions.h"
+#include "base/strings/utf_string_conversions.h"
 #include "components/autofill/core/browser/autofill_data_util.h"
 #include "components/autofill/core/browser/autofill_profile.h"
 #include "components/autofill/core/browser/credit_card.h"
 #include "components/autofill/core/browser/personal_data_manager.h"
 #include "components/autofill/core/browser/validation.h"
+#include "components/autofill/core/common/autofill_clock.h"
 #import "components/autofill/ios/browser/credit_card_util.h"
 #include "components/payments/core/payment_request_data_util.h"
 #include "components/payments/core/strings_util.h"
@@ -17,6 +19,7 @@
 #include "ios/chrome/browser/payments/payment_request.h"
 #import "ios/chrome/browser/payments/payment_request_util.h"
 #import "ios/chrome/browser/ui/autofill/autofill_ui_type.h"
+#import "ios/chrome/browser/ui/autofill/autofill_ui_type_util.h"
 #import "ios/chrome/browser/ui/payments/cells/accepted_payment_methods_item.h"
 #import "ios/chrome/browser/ui/payments/cells/payment_method_item.h"
 #import "ios/chrome/browser/ui/payments/payment_request_edit_consumer.h"
@@ -32,6 +35,41 @@ namespace {
 using ::autofill::data_util::GetIssuerNetworkForBasicCardIssuerNetwork;
 using ::autofill::data_util::GetPaymentRequestData;
 using ::payment_request_util::GetBillingAddressLabelFromAutofillProfile;
+
+// Returns true if |card_number| is a supported card type and a valid credit
+// card number and no other credit card with the same number exists.
+// |error_message| can't be null and will be filled with the appropriate error
+// message iff the return value is false.
+bool IsValidCreditCardNumber(const base::string16& card_number,
+                             payments::PaymentRequest* payment_request,
+                             const autofill::CreditCard* credit_card_to_edit,
+                             base::string16* error_message) {
+  std::set<std::string> supported_card_networks(
+      payment_request->supported_card_networks().begin(),
+      payment_request->supported_card_networks().end());
+  if (!::autofill::IsValidCreditCardNumberForBasicCardNetworks(
+          card_number, supported_card_networks, error_message)) {
+    return false;
+  }
+
+  // Check if another credit card has already been created with this number.
+  // TODO(crbug.com/725604): the UI should offer to load / update the existing
+  // credit card info.
+  autofill::CreditCard* existing_card =
+      payment_request->GetPersonalDataManager()->GetCreditCardByNumber(
+          base::UTF16ToASCII(card_number));
+  // If a card exists, it could be the one currently being edited.
+  if (!existing_card || (credit_card_to_edit && credit_card_to_edit->guid() ==
+                                                    existing_card->guid())) {
+    return true;
+  }
+  if (error_message) {
+    *error_message = l10n_util::GetStringUTF16(
+        IDS_PAYMENTS_VALIDATION_ALREADY_USED_CREDIT_CARD_NUMBER);
+  }
+  return false;
+}
+
 }  // namespace
 
 @interface CreditCardEditViewControllerMediator ()
@@ -186,6 +224,41 @@ using ::payment_request_util::GetBillingAddressLabelFromAutofillProfile;
   return NativeImage(resourceID);
 }
 
+#pragma mark - PaymentRequestEditViewControllerValidator
+
+- (NSString*)paymentRequestEditViewController:
+                 (PaymentRequestEditViewController*)controller
+                                validateField:(EditorField*)field {
+  if (field.value.length) {
+    base::string16 errorMessage;
+    base::string16 valueString = base::SysNSStringToUTF16(field.value);
+    if (field.autofillUIType == AutofillUITypeCreditCardNumber) {
+      ::IsValidCreditCardNumber(valueString, _paymentRequest, _creditCard,
+                                &errorMessage);
+    } else if (field.autofillUIType == AutofillUITypeCreditCardExpDate) {
+      NSArray<NSString*>* fieldComponents =
+          [field.value componentsSeparatedByString:@" / "];
+      int expMonth = [fieldComponents[0] intValue];
+      int expYear = [fieldComponents[1] intValue];
+      if (!autofill::IsValidCreditCardExpirationDate(
+              expYear, expMonth, autofill::AutofillClock::Now())) {
+        errorMessage = l10n_util::GetStringUTF16(
+            IDS_PAYMENTS_VALIDATION_INVALID_CREDIT_CARD_EXPIRED);
+      }
+    } else if (field.autofillUIType != AutofillUITypeCreditCardBillingAddress &&
+               field.autofillUIType != AutofillUITypeCreditCardSaveToChrome) {
+      autofill::IsValidForType(
+          valueString, ::AutofillTypeFromAutofillUIType(field.autofillUIType),
+          &errorMessage);
+    }
+    return !errorMessage.empty() ? base::SysUTF16ToNSString(errorMessage) : nil;
+  } else if (field.isRequired) {
+    return l10n_util::GetNSString(
+        IDS_PAYMENTS_FIELD_REQUIRED_VALIDATION_MESSAGE);
+  }
+  return nil;
+}
+
 #pragma mark - Helper methods
 
 // Queries the month and year numbers and informs the consumer.

ios/chrome/browser/ui/payments/credit_card_edit_mediator_unittest.mm

@@ -4,9 +4,12 @@
 
 #import "ios/chrome/browser/ui/payments/credit_card_edit_mediator.h"
 
+#include "base/time/time.h"
 #include "components/autofill/core/browser/autofill_test_utils.h"
+#include "components/autofill/core/browser/test_autofill_clock.h"
 #include "components/strings/grit/components_strings.h"
 #import "ios/chrome/browser/payments/payment_request_unittest_base.h"
+#import "ios/chrome/browser/ui/payments/payment_request_editor_field.h"
 #include "testing/platform_test.h"
 #include "third_party/ocmock/gtest_support.h"
 #include "ui/base/l10n/l10n_util.h"
@@ -15,12 +18,19 @@
 #error "This file requires ARC support."
 #endif
 
+namespace {
+
+const base::Time kOct2017 = base::Time::FromDoubleT(1509050356);
+
+}  // namespace
+
 class PaymentRequestCreditCardEditMediatorTest
     : public PaymentRequestUnitTestBase,
       public PlatformTest {
  protected:
   void SetUp() override {
     PaymentRequestUnitTestBase::SetUp();
+
     AddAutofillProfile(autofill::test::GetFullProfile());
     CreateTestPaymentRequest();
   }
@@ -28,6 +38,88 @@ class PaymentRequestCreditCardEditMediatorTest
   void TearDown() override { PaymentRequestUnitTestBase::TearDown(); }
 };
 
+// Tests that no validation error should be expected if validating an empty
+// field that is not required.
+TEST_F(PaymentRequestCreditCardEditMediatorTest, ValidateEmptyField) {
+  CreditCardEditViewControllerMediator* mediator =
+      [[CreditCardEditViewControllerMediator alloc]
+          initWithPaymentRequest:payment_request()
+                      creditCard:nil];
+
+  EditorField* field = [[EditorField alloc]
+      initWithAutofillUIType:AutofillUITypeProfileHomePhoneWholeNumber
+                   fieldType:EditorFieldTypeTextField
+                       label:@""
+                       value:@""
+                    required:NO];
+  NSString* validationError =
+      [mediator paymentRequestEditViewController:nil
+                                   validateField:(EditorField*)field];
+  EXPECT_TRUE(!validationError);
+}
+
+// Tests that the appropriate validation error should be expected if validating
+// an empty field that is required.
+TEST_F(PaymentRequestCreditCardEditMediatorTest, ValidateEmptyRequiredField) {
+  CreditCardEditViewControllerMediator* mediator =
+      [[CreditCardEditViewControllerMediator alloc]
+          initWithPaymentRequest:payment_request()
+                      creditCard:nil];
+
+  EditorField* field = [[EditorField alloc]
+      initWithAutofillUIType:AutofillUITypeProfileHomePhoneWholeNumber
+                   fieldType:EditorFieldTypeTextField
+                       label:@""
+                       value:@""
+                    required:YES];
+  NSString* validationError =
+      [mediator paymentRequestEditViewController:nil
+                                   validateField:(EditorField*)field];
+  EXPECT_TRUE([validationError
+      isEqualToString:l10n_util::GetNSString(
+                          IDS_PAYMENTS_FIELD_REQUIRED_VALIDATION_MESSAGE)]);
+}
+
+// Tests that the appropriate validation error should be expected if validating
+// a field with an invalid value.
+TEST_F(PaymentRequestCreditCardEditMediatorTest, ValidateFieldInvalidValue) {
+  CreditCardEditViewControllerMediator* mediator =
+      [[CreditCardEditViewControllerMediator alloc]
+          initWithPaymentRequest:payment_request()
+                      creditCard:nil];
+
+  EditorField* field = [[EditorField alloc]
+      initWithAutofillUIType:AutofillUITypeCreditCardNumber
+                   fieldType:EditorFieldTypeTextField
+                       label:@""
+                       value:@"411111111111111"  // Missing one last digit.
+                    required:YES];
+  NSString* validationError =
+      [mediator paymentRequestEditViewController:nil
+                                   validateField:(EditorField*)field];
+  EXPECT_TRUE([validationError
+      isEqualToString:
+          l10n_util::GetNSString(
+              IDS_PAYMENTS_CARD_NUMBER_INVALID_VALIDATION_MESSAGE)]);
+
+  autofill::TestAutofillClock test_clock;
+  test_clock.SetNow(kOct2017);
+
+  field = [[EditorField alloc]
+      initWithAutofillUIType:AutofillUITypeCreditCardExpDate
+                   fieldType:EditorFieldTypeTextField
+                       label:@""
+                       value:@"09 / 17"  // September 2017.
+                    required:YES];
+  validationError =
+      [mediator paymentRequestEditViewController:nil
+                                   validateField:(EditorField*)field];
+  EXPECT_TRUE([validationError
+      isEqualToString:
+          l10n_util::GetNSString(
+              IDS_PAYMENTS_VALIDATION_INVALID_CREDIT_CARD_EXPIRED)]);
+}
+
 // Tests that the editor's title is correct in various situations.
 TEST_F(PaymentRequestCreditCardEditMediatorTest, Title) {
   // No card, so the title should ask to add a card.

ios/chrome/browser/ui/payments/payment_request_edit_view_controller.h

@@ -12,6 +12,7 @@
 #import "ios/chrome/browser/ui/collection_view/collection_view_controller.h"
 #import "ios/chrome/browser/ui/payments/payment_request_edit_consumer.h"
 #import "ios/chrome/browser/ui/payments/payment_request_edit_view_controller_data_source.h"
+#import "ios/chrome/browser/ui/payments/payment_request_edit_view_controller_validator.h"
 
 extern NSString* const kWarningMessageAccessibilityID;
 
@@ -40,17 +41,6 @@ extern NSString* const kWarningMessageAccessibilityID;
 
 @end
 
-// Validator protocol for PaymentRequestEditViewController.
-@protocol PaymentRequestEditViewControllerValidator<NSObject>
-
-// Returns the validation error string for |field|. Returns nil if there are no
-// validation errors.
-- (NSString*)paymentRequestEditViewController:
-                 (PaymentRequestEditViewController*)controller
-                                validateField:(EditorField*)field;
-
-@end
-
 // The collection view controller for a generic Payment Request edit screen. It
 // features sections for every EditorField supplied to the initializer. Each
 // section has a text field as well as an error message item which is visible

ios/chrome/browser/ui/payments/payment_request_edit_view_controller_validator.h

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef IOS_CHROME_BROWSER_UI_PAYMENTS_PAYMENT_REQUEST_EDIT_VIEW_CONTROLLER_VALIDATOR_H_
+#define IOS_CHROME_BROWSER_UI_PAYMENTS_PAYMENT_REQUEST_EDIT_VIEW_CONTROLLER_VALIDATOR_H_
+
+#import <Foundation/Foundation.h>
+
+@class PaymentRequestEditViewController;
+@class EditorField;
+
+// Validator protocol for PaymentRequestEditViewController.
+@protocol PaymentRequestEditViewControllerValidator<NSObject>
+
+// Returns the validation error string for |field|. Returns nil if there are no
+// validation errors.
+- (NSString*)paymentRequestEditViewController:
+                 (PaymentRequestEditViewController*)controller
+                                validateField:(EditorField*)field;
+
+@end
+
+#endif  // IOS_CHROME_BROWSER_UI_PAYMENTS_PAYMENT_REQUEST_EDIT_VIEW_CONTROLLER_VALIDATOR_H_