Refactor test for exchange PLN to USD (pass)

src/main/kotlin/camilyed/github/io/currencyexchangeapi/domain/Account.kt

@@ -14,6 +14,8 @@ class Account(
     init {
         require(balancePln >= BigDecimal.ZERO) { "Initial balance cannot be negative" }
         require(balanceUsd == BigDecimal.ZERO) { "USD balance must start at 0" }
+        balancePln = balancePln.setScale(2)
+        balanceUsd = balanceUsd.setScale(2)
     }
 
     fun exchangePlnToUsd(amountPln: BigDecimal, exchangeRate: BigDecimal) {

src/test/kotlin/camilyed/github/io/currencyexchangeapi/application/AccountServiceTest.kt

@@ -31,21 +31,21 @@ class AccountServiceTest : SetNextAccountIdAbility {
         val account = create(
             anAccount()
                 .withOwner("Jan Kowalski")
-                .withInitialBalance(BigDecimal(1000.0))
+                .withInitialBalance("1000.00")
         )
 
         // then
         expectThat(account)
             .hasId("db59d3ba-5044-4ea9-85e2-aa1e67ec713c")
             .hasOwner("Jan Kowalski")
-            .hasBalanceInPln(1000.0)
+            .hasBalanceInPln("1000.00")
     }
 
     @Test
     fun `should throw exception when trying to create account with negative balance`() {
         // when
         val result = expectCatching {
-            create(anAccount().withInitialBalance(BigDecimal(-1000.0)))
+            create(anAccount().withInitialBalance("-1000.00"))
         }
 
         // then
@@ -58,26 +58,26 @@ class AccountServiceTest : SetNextAccountIdAbility {
     @Test
     fun `should have zero USD balance before exchange`() {
         // given
-        val account = create(anAccount().withInitialBalance(BigDecimal(1000.0)))
+        val account = create(anAccount().withInitialBalance("1000.00"))
 
         // then
         expectThat(account)
-            .hasBalanceInPln(1000.0)
-            .hasBalanceInUsd("0")
+            .hasBalanceInPln("1000.00")
+            .hasBalanceInUsd("0.00")
     }
 
     @Test
     fun `should exchange PLN to USD`() {
         // given
-        var account = create(anAccount().withInitialBalance(BigDecimal(1000.00)))
+        var account = create(anAccount().withInitialBalance("1000.00"))
         val exchangeRate = BigDecimal(4.0) // 1 USD = 4 PLN
 
         // when
         account = accountService.exchangePlnToUsd(account.id, BigDecimal(400.00), exchangeRate)
 
         // then
         expectThat(account)
-            .hasBalanceInPln(600.00)
+            .hasBalanceInPln("600.00")
             .hasBalanceInUsd("100.00")
     }
 

src/test/kotlin/camilyed/github/io/currencyexchangeapi/testing/assertions/AccountAssertions.kt

@@ -1,6 +1,5 @@
 package camilyed.github.io.currencyexchangeapi.testing.assertions
 
-import camilyed.github.io.currencyexchangeapi.domain.Account
 import camilyed.github.io.currencyexchangeapi.domain.AccountSnapshot
 import strikt.api.Assertion
 import java.math.BigDecimal
@@ -19,7 +18,7 @@ fun Assertion.Builder<AccountSnapshot>.hasOwner(expectedOwner: String) =
         if (it.owner == expectedOwner) pass() else fail()
     }
 
-fun Assertion.Builder<AccountSnapshot>.hasBalanceInPln(expectedBalance: Double) =
+fun Assertion.Builder<AccountSnapshot>.hasBalanceInPln(expectedBalance: String) =
     assert("has initial balance $expectedBalance") {
         if (it.balancePln == BigDecimal(expectedBalance)) pass() else fail(
             description = "in fact it is %s",

src/test/kotlin/camilyed/github/io/currencyexchangeapi/testing/builders/CreateAccountCommandBuilder.kt

@@ -8,7 +8,7 @@ class CreateAccountCommandBuilder private constructor() {
     private var initialBalance: BigDecimal = BigDecimal("100.00")
 
     fun withOwner(owner: String) = apply { this.owner = owner }
-    fun withInitialBalance(initialBalance: BigDecimal) = apply { this.initialBalance = initialBalance }
+    fun withInitialBalance(initialBalance: String) = apply { this.initialBalance = BigDecimal(initialBalance) }
 
     fun build(): CreateAccountCommand {
         return CreateAccountCommand(