Add unit tests

WooCommerce/src/test/kotlin/com/woocommerce/android/model/RefundMapperTest.kt

@@ -0,0 +1,99 @@
+package com.woocommerce.android.model
+
+import org.junit.Assert.assertEquals
+import org.junit.Test
+import org.wordpress.android.fluxc.model.metadata.WCMetaData
+import org.wordpress.android.fluxc.model.metadata.WCMetaDataValue
+import org.wordpress.android.fluxc.model.refunds.WCRefundModel
+import java.math.BigDecimal
+
+class RefundMapperTest {
+    @Test
+    fun `when mapping refund item from domain model, then extract its properties correctly`() {
+        val domainModel = WCRefundModel.WCRefundItem(
+            productId = 1,
+            quantity = -1,
+            itemId = 2,
+            name = "name",
+            variationId = null,
+            subtotal = BigDecimal.TEN,
+            total = BigDecimal.TEN,
+            totalTax = BigDecimal.TEN,
+            sku = "sku",
+            price = BigDecimal.TEN,
+            metaData = listOf(WCMetaData(id = 0, key = "_refunded_item_id", value = WCMetaDataValue(10)))
+        )
+
+        val appModel = domainModel.toAppModel()
+
+        assertEquals(1, appModel.productId)
+        assertEquals(1, appModel.quantity)
+        assertEquals(2, appModel.id)
+        assertEquals("name", appModel.name)
+        assertEquals(-1, appModel.variationId)
+        assertEquals(BigDecimal.TEN.negate(), appModel.subtotal)
+        assertEquals(BigDecimal.TEN.negate(), appModel.total)
+        assertEquals(BigDecimal.TEN.negate(), appModel.totalTax)
+        assertEquals("sku", appModel.sku)
+        assertEquals(BigDecimal.TEN, appModel.price)
+        assertEquals(10, appModel.orderItemId)
+    }
+
+    @Test
+    fun `given item ID is wrapped as String, when mapping refund item from domain model, then extract it correctly`() {
+        val domainModel = WCRefundModel.WCRefundItem(
+            productId = 1,
+            quantity = -1,
+            itemId = 2,
+            name = "name",
+            variationId = null,
+            subtotal = BigDecimal.TEN,
+            total = BigDecimal.TEN,
+            totalTax = BigDecimal.TEN,
+            sku = "sku",
+            price = BigDecimal.TEN,
+            metaData = listOf(WCMetaData(id = 0, key = "_refunded_item_id", value = WCMetaDataValue("10")))
+        )
+
+        val appModel = domainModel.toAppModel()
+
+        assertEquals(10, appModel.orderItemId)
+    }
+
+    @Test
+    fun `when mapping shipping lines from domain model, then extract its properties correctly`() {
+        val domainModel = WCRefundModel.WCRefundShippingLine(
+            id = 1,
+            methodId = "methodId",
+            methodTitle = "methodTitle",
+            totalTax = BigDecimal.TEN,
+            total = BigDecimal.TEN,
+            metaData = listOf(WCMetaData(id = 0, key = "_refunded_item_id", value = WCMetaDataValue(10)))
+        )
+
+        val appModel = domainModel.toAppModel()
+
+        // Intentionally not checking all properties, we have an inconsistency in the function where
+        // we negate the totalTax but not the total, and there is no explanation for this.
+        // See https://github.com/woocommerce/woocommerce-android/pull/5517#discussion_r774573314
+        // We should update the test when we have a clear understanding of the expected behavior.
+        // Note: these properties are not used in the app currently.
+        assertEquals(10, appModel.itemId)
+    }
+
+    @Test
+    fun `when mapping fee lines from domain model, then extract its properties correctly`() {
+        val domainModel = WCRefundModel.WCRefundFeeLine(
+            id = 1,
+            name = "name",
+            totalTax = BigDecimal.TEN,
+            total = BigDecimal.TEN,
+            metaData = listOf(WCMetaData(id = 0, key = "_refunded_item_id", value = WCMetaDataValue(10)))
+        )
+
+        val appModel = domainModel.toAppModel()
+
+        // See comment in the previous test.
+        assertEquals(10, appModel.id)
+    }
+}