Update vertical mode UI in more places to fix issues where error or p… (

#3733)

…rimary button state is not updated

## Motivation
- Bug where pay button is not updated after removing saved pms
- Bug where error message isn't cleared when tapping another PM in the
list or going
- Bug where error message animation was funky

## Testing
Manual + automated UI test.

Example/PaymentSheet Example/PaymentSheetUITest/PaymentSheetVerticalUITest.swift

@@ -123,10 +123,13 @@ class PaymentSheetVerticalUITests: PaymentSheetUITestCase {
         // Fail payment
         app.buttons["Pay $50.99"].tap()
         app.waitForButtonOrStaticText("FAIL TEST PAYMENT").tap()
-        XCTAssertTrue(app.staticTexts["We are unable to authenticate your payment method. Please choose a different payment method and try again."].waitForExistence(timeout: 10))
+        let errorMessage = app.staticTexts["We are unable to authenticate your payment method. Please choose a different payment method and try again."]
+        XCTAssertTrue(errorMessage.waitForExistence(timeout: 10))
 
         // Try Cash App Pay
         app.buttons["Cash App Pay"].waitForExistenceAndTap()
+        // Validate error disappears
+        XCTAssertFalse(errorMessage.waitForExistence(timeout: 0.1))
         app.buttons["Pay $50.99"].tap()
         app.waitForButtonOrStaticText("AUTHORIZE TEST PAYMENT").tap()
         XCTAssertTrue(app.staticTexts["Success!"].waitForExistence(timeout: 10))
@@ -184,7 +187,7 @@ class PaymentSheetVerticalUITests: PaymentSheetUITestCase {
         XCTAssertTrue(app.staticTexts["Select card"].waitForExistence(timeout: 5.0))
         XCTAssertTrue(app.buttons["Edit"].waitForExistenceAndTap())
 
-        // Remove both the payment methods just added
+        // Remove one of the payment methods just added
         app.buttons["CircularButton.Remove"].firstMatch.waitForExistenceAndTap()
         XCTAssertTrue(app.alerts.buttons["Remove"].waitForExistenceAndTap())
 
@@ -225,6 +228,8 @@ class PaymentSheetVerticalUITests: PaymentSheetUITestCase {
         XCTAssertTrue(app.buttons["Card"].waitForExistence(timeout: 5.0))
         // Verify there's no more Saved section
         XCTAssertFalse(app.staticTexts["Saved"].waitForExistence(timeout: 0.1))
+        // Verify primary button isn't enabled b/c there is no selected PM
+        XCTAssertFalse(app.buttons["Set up"].isEnabled)
     }
 
     private func setupCards(cards: [String], settings: PaymentSheetTestPlaygroundSettings) {

StripePaymentSheet/StripePaymentSheet/Source/PaymentSheet/ViewControllers/PaymentSheetVerticalViewController.swift

@@ -145,12 +145,9 @@ class PaymentSheetVerticalViewController: UIViewController, FlowControllerViewCo
         regenerateUI()
         // Only use the previous customer input for the first form shown
         self.previousPaymentOption = nil
-        updatePrimaryButton()
-        updateMandate(animated: false)
-        updateError()
     }
 
-    /// Regenerates the main content - either the PM list or the PM form
+    /// Regenerates the main content - either the PM list or the PM form and updates all UI elements (pay button, error, mandate)
     func regenerateUI(updatedListSelection: VerticalPaymentMethodListSelection? = nil) {
         // Remove any content vcs; we'll rebuild and add them now
         if let paymentMethodListViewController {
@@ -182,6 +179,14 @@ class PaymentSheetVerticalViewController: UIViewController, FlowControllerViewCo
                 add(childViewController: paymentMethodListViewController, containerView: paymentContainerView)
             }
         }
+        updateUI()
+    }
+
+    /// Updates all UI elements (pay button, error, mandate)
+    func updateUI() {
+        updatePrimaryButton()
+        updateMandate()
+        updateError()
     }
 
     func updatePrimaryButton() {
@@ -236,7 +241,7 @@ class PaymentSheetVerticalViewController: UIViewController, FlowControllerViewCo
 
     func updateError() {
         errorLabel.text = error?.nonGenericDescription
-        UIView.animate(withDuration: PaymentSheetUI.defaultAnimationDuration) {
+        animateHeightChange {
             self.errorLabel.setHiddenIfNecessary(self.error == nil)
         }
     }
@@ -480,6 +485,7 @@ class PaymentSheetVerticalViewController: UIViewController, FlowControllerViewCo
     }
 
     @objc func presentManageScreen() {
+        error = nil
         // Special case, only 1 card remaining but is co-branded, show update view controller
         if savedPaymentMethods.count == 1,
            let paymentMethod = savedPaymentMethods.first,
@@ -569,6 +575,7 @@ extension PaymentSheetVerticalViewController: VerticalPaymentMethodListViewContr
     }
 
     func didTapPaymentMethod(_ selection: VerticalPaymentMethodListSelection) {
+        error = nil
 #if !canImport(CompositorServices)
         UISelectionFeedbackGenerator().selectionChanged()
 #endif
@@ -584,8 +591,7 @@ extension PaymentSheetVerticalViewController: VerticalPaymentMethodListViewContr
                 navigationBar.setStyle(.back(showAdditionalButton: false))
             }
         }
-        updatePrimaryButton()
-        updateMandate()
+        updateUI()
     }
 
     func didTapSavedPaymentMethodAccessoryButton() {
@@ -644,9 +650,7 @@ extension PaymentSheetVerticalViewController: SheetNavigationBarDelegate {
         paymentMethodFormViewController = nil
         switchContentIfNecessary(to: paymentMethodListViewController!, containerView: paymentContainerView)
         navigationBar.setStyle(.close(showAdditionalButton: false))
-        updatePrimaryButton()
-        updateMandate()
-        updateError()
+        updateUI()
     }
 }
 

StripePaymentSheet/StripePaymentSheetTests/PaymentSheet/PaymentSheetVerticalViewControllerSnapshotTest.swift

@@ -215,10 +215,12 @@ final class PaymentSheetVerticalViewControllerSnapshotTest: STPSnapshotTestCase
         // Take another snapshot displaying the mandate
         let listVC = sut.paymentMethodListViewController!
         listVC.didTap(rowButton: listVC.getRowButton(accessibilityIdentifier: "Cash App Pay"), selection: .new(paymentMethodType: .stripe(.cashApp)))
+        sut.updateErrorLabel(for: MockError())
         verify(sut, identifier: "under_list_with_mandate")
 
         // Take another snapshot displaying the form
         sut.didTapPaymentMethod(.new(paymentMethodType: .stripe(.USBankAccount)))
+        sut.updateErrorLabel(for: MockError())
         verify(sut, identifier: "under_form")
     }