Correctly validate country field on shipping address form

- Validation was being incorrectly skipped in
  `PaymentFlowActivity`. Use
  `ShippingInfoWidget#shippingInformation` instead
  of `rawShippingInformation`.
- Implement a `AutoCompleteTextView.Validator` in
  `CountryAutoCompleteTextView` and show an error
  message if the text is an invalid country.
- When a user submits their shipping information in
  `PaymentFlowActivity`, perform validation using
  the `AutoCompleteTextView.Validator`.
- Add string resource `address_country_invalid`.
  Create JIRA for translation.

ANDROID-451

stripe/res/layout/country_autocomplete_textview.xml

@@ -1,15 +1,14 @@
 <?xml version="1.0" encoding="utf-8"?>
 <merge xmlns:android="http://schemas.android.com/apk/res/android"
-       android:layout_width="match_parent"
-       android:layout_height="wrap_content"
-    >
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content">
 
     <com.google.android.material.textfield.TextInputLayout
         android:id="@+id/tl_country_cat"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:hint="@string/address_label_country"
-        >
+        android:labelFor="@id/autocomplete_country_cat">
 
         <AutoCompleteTextView
             android:id="@+id/autocomplete_country_cat"

stripe/res/values/strings.xml

@@ -71,6 +71,11 @@
     <string name="address_postal_code_invalid">Your postal code is invalid</string>
     <!--Error text indicating zip/ postal code is invalid, used for international addresses-->
     <string name="address_zip_postal_invalid">Your ZIP/Postal code is invalid</string>
+
+    <!-- TODO(mshafrir-stripe): translate string (ANDROID-450) -->
+    <!--Error text indicating country is invalid-->
+    <string name="address_country_invalid" tools:ignore="MissingTranslation">Your country is invalid</string>
+
     <!--Label for input requesting province, used for canadian addresses-->
     <string name="address_label_province">Province</string>
     <!--Label for input requesting province where province is optional, used for canadian addresses-->

stripe/src/main/java/com/stripe/android/view/CountryAdapter.kt

@@ -18,7 +18,7 @@ import java.util.Locale
  */
 internal class CountryAdapter(
     context: Context,
-    private var unfilteredCountries: List<Country>
+    internal var unfilteredCountries: List<Country>
 ) : ArrayAdapter<Country>(context, R.layout.country_text_view) {
     private val countryFilter: CountryFilter = CountryFilter(
         unfilteredCountries,

stripe/src/main/java/com/stripe/android/view/CountryAutoCompleteTextView.kt

@@ -11,19 +11,21 @@ import androidx.annotation.VisibleForTesting
 import androidx.core.os.ConfigurationCompat
 import com.stripe.android.R
 import java.util.Locale
+import kotlinx.android.synthetic.main.country_autocomplete_textview.view.*
 
 internal class CountryAutoCompleteTextView @JvmOverloads constructor(
     context: Context,
     attrs: AttributeSet? = null,
     defStyleAttr: Int = 0
 ) : FrameLayout(context, attrs, defStyleAttr) {
-    private val countryAutocomplete: AutoCompleteTextView
+    @VisibleForTesting
+    internal val countryAutocomplete: AutoCompleteTextView
 
     /**
      * @return 2 digit country code of the country selected by this input.
      */
     @VisibleForTesting
-    var selectedCountry: Country
+    var selectedCountry: Country?
 
     @JvmSynthetic
     internal var countryChangeCallback: (Country) -> Unit = {}
@@ -58,6 +60,30 @@ internal class CountryAutoCompleteTextView @JvmOverloads constructor(
 
         selectedCountry = countryAdapter.firstItem
         updateInitialCountry()
+
+        val errorMessage = resources.getString(R.string.address_country_invalid)
+        countryAutocomplete.validator = object : AutoCompleteTextView.Validator {
+            override fun fixText(invalidText: CharSequence?): CharSequence {
+                return invalidText ?: ""
+            }
+
+            override fun isValid(text: CharSequence?): Boolean {
+                val validCountry = countryAdapter.unfilteredCountries.firstOrNull {
+                    it.name == text.toString()
+                }
+
+                return if (validCountry != null) {
+                    selectedCountry = validCountry
+                    clearError()
+                    true
+                } else {
+                    selectedCountry = null
+                    tl_country_cat.error = errorMessage
+                    tl_country_cat.isErrorEnabled = true
+                    false
+                }
+            }
+        }
     }
 
     private fun updateInitialCountry() {
@@ -94,12 +120,13 @@ internal class CountryAutoCompleteTextView @JvmOverloads constructor(
         val displayCountry = country?.let {
             updatedSelectedCountryCode(it)
             displayCountryEntered
-        } ?: selectedCountry.name
+        } ?: selectedCountry?.name
 
         countryAutocomplete.setText(displayCountry)
     }
 
     private fun updatedSelectedCountryCode(country: Country) {
+        clearError()
         if (selectedCountry != country) {
             selectedCountry = country
             countryChangeCallback(country)
@@ -110,4 +137,13 @@ internal class CountryAutoCompleteTextView @JvmOverloads constructor(
         return CountryUtils.getCountryByCode(countryCode)?.name
             ?: Locale("", countryCode).displayCountry
     }
+
+    internal fun validateCountry() {
+        countryAutocomplete.performValidation()
+    }
+
+    private fun clearError() {
+        tl_country_cat.error = null
+        tl_country_cat.isErrorEnabled = false
+    }
 }

stripe/src/main/java/com/stripe/android/view/PaymentFlowActivity.kt

@@ -19,6 +19,7 @@ import com.stripe.android.model.Customer
 import com.stripe.android.model.ShippingInformation
 import com.stripe.android.model.ShippingMethod
 import java.lang.ref.WeakReference
+import kotlinx.android.synthetic.main.activity_enter_shipping_info.*
 import kotlinx.android.synthetic.main.activity_shipping_flow.*
 
 /**
@@ -189,8 +190,7 @@ class PaymentFlowActivity : StripeActivity() {
 
     private val shippingInfo: ShippingInformation?
         get() {
-            val shippingInfoWidget: ShippingInfoWidget = findViewById(R.id.shipping_info_widget)
-            return shippingInfoWidget.rawShippingInformation
+            return shipping_info_widget.shippingInformation
         }
 
     private val selectedShippingMethod: ShippingMethod?

stripe/src/main/java/com/stripe/android/view/ShippingInfoWidget.kt

@@ -57,18 +57,17 @@ class ShippingInfoWidget @JvmOverloads constructor(
     /**
      * Return [ShippingInformation] based on user input.
      */
-    internal val rawShippingInformation: ShippingInformation
+    private val rawShippingInformation: ShippingInformation
         get() {
-            val address = Address.Builder()
-                .setCity(cityEditText.text?.toString())
-                .setCountry(countryAutoCompleteTextView.selectedCountry.code)
-                .setLine1(addressEditText.text?.toString())
-                .setLine2(addressEditText2.text?.toString())
-                .setPostalCode(postalCodeEditText.text?.toString())
-                .setState(stateEditText.text?.toString())
-                .build()
             return ShippingInformation(
-                address,
+                Address.Builder()
+                    .setCity(cityEditText.text?.toString())
+                    .setCountry(countryAutoCompleteTextView.selectedCountry?.code)
+                    .setLine1(addressEditText.text?.toString())
+                    .setLine2(addressEditText2.text?.toString())
+                    .setPostalCode(postalCodeEditText.text?.toString())
+                    .setState(stateEditText.text?.toString())
+                    .build(),
                 nameEditText.text?.toString(),
                 phoneNumberEditText.text?.toString()
             )
@@ -136,7 +135,7 @@ class ShippingInfoWidget @JvmOverloads constructor(
         optionalShippingInfoFields = optionalAddressFields.orEmpty()
         renderLabels()
 
-        countryAutoCompleteTextView.selectedCountry.let(::renderCountrySpecificLabels)
+        countryAutoCompleteTextView.selectedCountry?.let(::renderCountrySpecificLabels)
     }
 
     /**
@@ -147,7 +146,7 @@ class ShippingInfoWidget @JvmOverloads constructor(
         hiddenShippingInfoFields = hiddenAddressFields.orEmpty()
         renderLabels()
 
-        countryAutoCompleteTextView.selectedCountry.let(::renderCountrySpecificLabels)
+        countryAutoCompleteTextView.selectedCountry?.let(::renderCountrySpecificLabels)
     }
 
     /**
@@ -191,9 +190,12 @@ class ShippingInfoWidget @JvmOverloads constructor(
         val postalCode = postalCodeEditText.text?.toString() ?: return false
         val phoneNumber = phoneNumberEditText.text?.toString() ?: return false
 
+        countryAutoCompleteTextView.validateCountry()
+        val selectedCountry = countryAutoCompleteTextView.selectedCountry
+
         val isPostalCodeValid = shippingPostalCodeValidator.isValid(
             postalCode,
-            countryAutoCompleteTextView.selectedCountry.code,
+            selectedCountry?.code,
             optionalShippingInfoFields,
             hiddenShippingInfoFields
         )
@@ -219,7 +221,8 @@ class ShippingInfoWidget @JvmOverloads constructor(
         phoneNumberEditText.shouldShowError = requiredPhoneNumberEmpty
 
         return isPostalCodeValid && !requiredAddressLine1Empty && !requiredCityEmpty &&
-            !requiredStateEmpty && !requiredNameEmpty && !requiredPhoneNumberEmpty
+            !requiredStateEmpty && !requiredNameEmpty && !requiredPhoneNumberEmpty &&
+            selectedCountry != null
     }
 
     private fun isFieldRequired(@CustomizableShippingField field: String): Boolean {
@@ -241,7 +244,7 @@ class ShippingInfoWidget @JvmOverloads constructor(
         setupErrorHandling()
         renderLabels()
 
-        countryAutoCompleteTextView.selectedCountry.let(::renderCountrySpecificLabels)
+        countryAutoCompleteTextView.selectedCountry?.let(::renderCountrySpecificLabels)
     }
 
     private fun setupErrorHandling() {

stripe/src/main/java/com/stripe/android/view/ShippingPostalCodeValidator.kt

@@ -10,20 +10,26 @@ internal class ShippingPostalCodeValidator {
 
     fun isValid(
         postalCode: String,
-        countryCode: String,
+        countryCode: String?,
         optionalShippingInfoFields: List<String>,
         hiddenShippingInfoFields: List<String>
     ): Boolean {
+        if (countryCode == null) {
+            return false
+        }
+
         val postalCodePattern = POSTAL_CODE_PATTERNS[countryCode]
         return if (postalCode.isEmpty() &&
             isPostalCodeOptional(optionalShippingInfoFields, hiddenShippingInfoFields)) {
             true
-        } else postalCodePattern?.matcher(postalCode)?.matches()
-            ?: if (CountryUtils.doesCountryUsePostalCode(countryCode)) {
-                postalCode.isNotEmpty()
-            } else {
-                true
-            }
+        } else {
+            postalCodePattern?.matcher(postalCode)?.matches()
+                ?: if (CountryUtils.doesCountryUsePostalCode(countryCode)) {
+                    postalCode.isNotEmpty()
+                } else {
+                    true
+                }
+        }
     }
 
     private companion object {

stripe/src/test/java/com/stripe/android/view/CountryAutoCompleteTextViewTest.kt

@@ -9,6 +9,7 @@ import kotlin.test.Test
 import kotlin.test.assertEquals
 import kotlin.test.assertFalse
 import kotlin.test.assertNotEquals
+import kotlin.test.assertNotNull
 import kotlin.test.assertNull
 import kotlin.test.assertTrue
 import org.junit.runner.RunWith
@@ -37,13 +38,14 @@ class CountryAutoCompleteTextViewTest : BaseViewTest<ShippingInfoTestActivity>(
 
     @Test
     fun countryAutoCompleteTextView_whenInitialized_displaysDefaultLocaleDisplayName() {
-        assertEquals(Locale.US.country, countryAutoCompleteTextView.selectedCountry.code)
+        assertEquals(Locale.US.country, countryAutoCompleteTextView.selectedCountry?.code)
         assertEquals(Locale.US.displayCountry, autoCompleteTextView.text.toString())
     }
 
     @Test
     fun updateUIForCountryEntered_whenInvalidCountry_revertsToLastCountry() {
-        val previousValidCountryCode = countryAutoCompleteTextView.selectedCountry.code
+        val previousValidCountryCode =
+            countryAutoCompleteTextView.selectedCountry?.code.orEmpty()
         countryAutoCompleteTextView.setCountrySelected("FAKE COUNTRY CODE")
         assertNull(autoCompleteTextView.error)
         assertEquals(autoCompleteTextView.text.toString(),
@@ -56,9 +58,9 @@ class CountryAutoCompleteTextViewTest : BaseViewTest<ShippingInfoTestActivity>(
 
     @Test
     fun updateUIForCountryEntered_whenValidCountry_UIUpdates() {
-        assertEquals(Locale.US.country, countryAutoCompleteTextView.selectedCountry.code)
+        assertEquals(Locale.US.country, countryAutoCompleteTextView.selectedCountry?.code)
         countryAutoCompleteTextView.setCountrySelected(Locale.UK.country)
-        assertEquals(Locale.UK.country, countryAutoCompleteTextView.selectedCountry.code)
+        assertEquals(Locale.UK.country, countryAutoCompleteTextView.selectedCountry?.code)
     }
 
     @Test
@@ -74,10 +76,26 @@ class CountryAutoCompleteTextViewTest : BaseViewTest<ShippingInfoTestActivity>(
         countryAutoCompleteTextView.setAllowedCountryCodes(setOf("fr", "de"))
         assertEquals(
             "FR",
-            countryAutoCompleteTextView.selectedCountry.code
+            countryAutoCompleteTextView.selectedCountry?.code
         )
     }
 
+    @Test
+    fun validateCountry_withInvalidCountry_setsSelectedCountryToNull() {
+        assertNotNull(countryAutoCompleteTextView.selectedCountry)
+        countryAutoCompleteTextView.countryAutocomplete.setText("invalid country")
+        countryAutoCompleteTextView.validateCountry()
+        assertNull(countryAutoCompleteTextView.selectedCountry)
+    }
+
+    @Test
+    fun validateCountry_withValidCountry_setsSelectedCountry() {
+        assertNotNull(countryAutoCompleteTextView.selectedCountry)
+        countryAutoCompleteTextView.countryAutocomplete.setText("Canada")
+        countryAutoCompleteTextView.validateCountry()
+        assertEquals("Canada", countryAutoCompleteTextView.selectedCountry?.name)
+    }
+
     @AfterTest
     fun teardown() {
         Locale.setDefault(Locale.US)

stripe/src/test/java/com/stripe/android/view/ShippingInfoWidgetTest.kt

@@ -226,7 +226,7 @@ class ShippingInfoWidgetTest : BaseViewTest<ShippingInfoTestActivity>(
         assertEquals(phoneEditText.text.toString(), "(123) 456 - 7890")
         assertEquals(postalEditText.text.toString(), "12345")
         assertEquals(nameEditText.text.toString(), "Fake Name")
-        assertEquals(countryAutoCompleteTextView.selectedCountry.code, "US")
+        assertEquals(countryAutoCompleteTextView.selectedCountry?.code, "US")
     }
 
     private companion object {