feat: Publishes change event from CardVerificationCodeElement on bran…

…d changes (#30)
Basis-Theory · Jan 5, 2023 · 6e8072a · 6e8072a
1 parent 06dda5d
commit 6e8072a
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Showing 4 changed files with 105 additions and 11 deletions.
diff --git a/lib/src/main/java/com/basistheory/android/view/CardVerificationCodeElement.kt b/lib/src/main/java/com/basistheory/android/view/CardVerificationCodeElement.kt
@@ -16,9 +16,8 @@ class CardVerificationCodeElement @JvmOverloads constructor(
         set(value) {
             if (value != null && cardNumberElement !== value) {
                 field = value
-                super.mask =
-                    cardNumberElement?.cardMetadata?.cvcMask?.let { ElementMask(it) } ?: defaultMask
-                field?.addChangeEventListener { updateMask() }
+                onCardNumberChanged(true)
+                field?.addChangeEventListener { onCardNumberChanged() }
             } else {
                 field = value
             }
@@ -27,7 +26,7 @@ class CardVerificationCodeElement @JvmOverloads constructor(
     init {
         super.keyboardType = KeyboardType.NUMBER
         super.mask = defaultMask
-        super.validator = RegexValidator("""^\d{3,4}$""")
+        super.validator = validatorForLength(defaultMask.length)
     }
 
     companion object {
@@ -36,10 +35,27 @@ class CardVerificationCodeElement @JvmOverloads constructor(
         val defaultMask = ElementMask(
             listOf(digit, digit, digit)
         )
+
+        fun validatorForLength(length: Int) =
+            RegexValidator("""^\d{$length}$""")
     }
 
-    private fun updateMask() {
-        super.mask =
-            cardNumberElement?.cardMetadata?.cvcMask?.let { ElementMask(it) } ?: defaultMask
+    private fun onCardNumberChanged(isInitialConfiguration: Boolean = false) {
+        val oldMaskLength = super.mask?.length
+
+        val updatedMask = cardNumberElement
+            ?.cardMetadata
+            ?.cvcMask
+            ?.let { ElementMask(it) }
+            ?: defaultMask
+
+        super.mask = updatedMask
+        super.validator = validatorForLength(updatedMask.length)
+
+        val updatedMaskLength = super.mask?.length
+
+        // publish a change event if the mask length changed
+        if (!isInitialConfiguration && oldMaskLength != updatedMaskLength)
+            super.publishChangeEvent()
     }
 }
diff --git a/lib/src/main/java/com/basistheory/android/view/TextElement.kt b/lib/src/main/java/com/basistheory/android/view/TextElement.kt
@@ -215,6 +215,9 @@ open class TextElement @JvmOverloads constructor(
         isInternalChange = false
     }
 
+    protected fun publishChangeEvent()
+        = publishChangeEvent(editText.editableText)
+
     private fun publishChangeEvent(editable: Editable?) {
         val event = createElementChangeEvent(
             getText(),

diff --git a/lib/src/main/java/com/basistheory/android/view/mask/ElementMask.kt b/lib/src/main/java/com/basistheory/android/view/mask/ElementMask.kt
@@ -16,6 +16,9 @@ class ElementMask {
         )
     }
 
+    val length: Int
+        get() = characterMasks.size
+
     internal fun evaluate(text: String?, action: InputAction): String? {
         if (text.isNullOrEmpty())
             return ""

diff --git a/lib/src/test/java/com/basistheory/android/view/CardVerificationCodeElementTests.kt b/lib/src/test/java/com/basistheory/android/view/CardVerificationCodeElementTests.kt
@@ -14,10 +14,8 @@ import org.junit.runner.RunWith
 import org.robolectric.Robolectric
 import org.robolectric.RobolectricTestRunner
 import strikt.api.expectThat
-import strikt.assertions.isEqualTo
-import strikt.assertions.isFalse
-import strikt.assertions.isTrue
-import strikt.assertions.single
+import strikt.assertions.*
+import kotlin.text.get
 
 @RunWith(RobolectricTestRunner::class)
 class CardVerificationCodeElementTests {
@@ -96,4 +94,78 @@ class CardVerificationCodeElementTests {
 
         verify(exactly = 1) { cardNumberElement.addChangeEventListener(any()) }
     }
+
+    @Test
+    fun `emits a change event when mask increases from 3 to 4 chars`() {
+        val changeEvents = mutableListOf<ChangeEvent>()
+        cvcElement.addChangeEventListener { changeEvents.add(it) }
+
+        cardNumberElement.setText("4242424242424242")
+        cvcElement.cardNumberElement = cardNumberElement
+        cvcElement.setText("123")
+
+        expectThat(changeEvents).single().and {
+            get { isValid }.isTrue()
+            get { isEmpty }.isFalse()
+            get { isComplete }.isTrue()
+        }
+
+        // change the card brand from visa to american-express
+        cardNumberElement.setText("378282246310005")
+
+        expectThat(cvcElement.getText()).isEqualTo("123") // value does not change
+        expectThat(changeEvents).hasSize(2).last().and {
+            get { isValid }.isFalse()
+            get { isEmpty }.isFalse()
+            get { isComplete }.isFalse()
+        }
+    }
+
+    @Test
+    fun `emits a change event when mask decreases from 4 to 3 chars`() {
+        val changeEvents = mutableListOf<ChangeEvent>()
+        cvcElement.addChangeEventListener { changeEvents.add(it) }
+
+        cardNumberElement.setText("378282246310005")
+        cvcElement.cardNumberElement = cardNumberElement
+        cvcElement.setText("1234")
+
+        expectThat(changeEvents).single().and {
+            get { isValid }.isTrue()
+            get { isEmpty }.isFalse()
+            get { isComplete }.isTrue()
+        }
+
+        // change the card brand from visa to american-express
+        cardNumberElement.setText("4242424242424242")
+
+        expectThat(cvcElement.getText()).isEqualTo("1234") // value does not change
+        expectThat(changeEvents).hasSize(2).last().and {
+            get { isValid }.isFalse()
+            get { isEmpty }.isFalse()
+            get { isComplete }.isFalse()
+        }
+    }
+
+    @Test
+    fun `does NOT emit a change event when card brand changes without impacting cvc mask`() {
+        val changeEvents = mutableListOf<ChangeEvent>()
+        cvcElement.addChangeEventListener { changeEvents.add(it) }
+
+        cardNumberElement.setText("4242424242424242")
+        cvcElement.cardNumberElement = cardNumberElement
+        cvcElement.setText("1234")
+
+        expectThat(changeEvents).single().and {
+            get { isValid }.isTrue()
+            get { isEmpty }.isFalse()
+            get { isComplete }.isTrue()
+        }
+
+        // change the card brand from visa to mastercard
+        cardNumberElement.setText("5555555555554444")
+
+        expectThat(cvcElement.getText()).isEqualTo("123") // value does not change
+        expectThat(changeEvents).single() // no new change events were published
+    }
 }