Convert PayPalCreditFinancingAmountUnitTest from Java to Kotlin (#1390)

* Rename .java to .kt

* convert `PayPalCreditFinancingAmountUnitTest` from Java to Kotlin

Author: noguier

PayPal/src/test/java/com/braintreepayments/api/paypal/PayPalCreditFinancingAmountUnitTest.java

@@ -0,0 +1,73 @@
+package com.braintreepayments.api.paypal
+
+import android.os.Parcel
+import kotlinx.parcelize.parcelableCreator
+import org.json.JSONException
+import org.json.JSONObject
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNotNull
+import org.junit.Assert.assertNull
+import org.robolectric.RobolectricTestRunner
+
+@RunWith(RobolectricTestRunner::class)
+class PayPalCreditFinancingAmountUnitTest {
+
+    @Test
+    fun `from JSON returns empty object if null`() {
+        val creditFinancingAmount = PayPalCreditFinancingAmount.fromJson(null)
+
+        assertNotNull(creditFinancingAmount)
+        assertNull(creditFinancingAmount.currency)
+        assertNull(creditFinancingAmount.value)
+    }
+
+    @Test
+    @Throws(JSONException::class)
+    fun `creates CreditFinancingAmount from standard JSON`() {
+        val json = "{\"currency\": \"USD\", \"value\": \"123.45\"}"
+        val creditFinancingAmount = PayPalCreditFinancingAmount.fromJson(JSONObject(json))
+
+        assertEquals("USD", creditFinancingAmount.currency)
+        assertEquals("123.45", creditFinancingAmount.value)
+    }
+
+    @Test
+    @Throws(JSONException::class)
+    fun `creates CreditFinancingAmount from JSON with missing currency`() {
+        val json = "{\"value\": \"123.45\"}"
+        val creditFinancingAmount = PayPalCreditFinancingAmount.fromJson(JSONObject(json))
+
+        assertNull(creditFinancingAmount.currency)
+        assertEquals("123.45", creditFinancingAmount.value)
+    }
+
+    @Test
+    @Throws(JSONException::class)
+    fun `creates CreditFinancingAmount from JSON with missing value`() {
+        val json = "{\"currency\": \"USD\"}"
+        val creditFinancingAmount = PayPalCreditFinancingAmount.fromJson(JSONObject(json))
+
+        assertNull(creditFinancingAmount.value)
+        assertEquals("USD", creditFinancingAmount.currency)
+    }
+
+    @Test
+    @Throws(JSONException::class)
+    fun `write to Parcel serializes correctly`() {
+        val json = "{\"currency\": \"USD\", \"value\": \"123.45\"}"
+        val preSerialized = PayPalCreditFinancingAmount.fromJson(JSONObject(json))
+
+        val parcel = Parcel.obtain().apply {
+            preSerialized.writeToParcel(this, 0)
+            setDataPosition(0)
+        }
+
+        val creditFinancingAmount = parcelableCreator<PayPalCreditFinancingAmount>().createFromParcel(parcel)
+
+        assertNotNull(creditFinancingAmount)
+        assertEquals("USD", creditFinancingAmount.currency)
+        assertEquals("123.45", creditFinancingAmount.value)
+    }
+}