From 64707ff810cca0b92734c83a3de33123e9836126 Mon Sep 17 00:00:00 2001
From: djmil <andriy@djmil.dev>
Date: Tue, 18 Jul 2023 19:23:49 +0200
Subject: [PATCH] TDD for CashCard contract

---
 src/main/java/djmil/cashcard/CashCard.java    |  5 +++
 .../java/djmil/cashcard/CashCardJsonTest.java | 43 ++++++++++++++++++-
 .../resources/djmil/cashcard/expected.json    |  4 ++
 3 files changed, 50 insertions(+), 2 deletions(-)
 create mode 100644 src/main/java/djmil/cashcard/CashCard.java
 create mode 100644 src/test/resources/djmil/cashcard/expected.json

diff --git a/src/main/java/djmil/cashcard/CashCard.java b/src/main/java/djmil/cashcard/CashCard.java
new file mode 100644
index 0000000..4bc5397
--- /dev/null
+++ b/src/main/java/djmil/cashcard/CashCard.java
@@ -0,0 +1,5 @@
+package djmil.cashcard;
+
+public record CashCard(Long id, Double amount) {
+    
+}
diff --git a/src/test/java/djmil/cashcard/CashCardJsonTest.java b/src/test/java/djmil/cashcard/CashCardJsonTest.java
index bd2a2df..df620f2 100644
--- a/src/test/java/djmil/cashcard/CashCardJsonTest.java
+++ b/src/test/java/djmil/cashcard/CashCardJsonTest.java
@@ -1,13 +1,52 @@
 package djmil.cashcard;
 
 import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.json.JsonTest;
+import org.springframework.boot.test.json.JacksonTester;
+
+import java.io.IOException;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
+@JsonTest
 public class CashCardJsonTest {
 
-@Test
+    @Autowired
+    private JacksonTester<CashCard> json;
+
+    @Test
     public void myFirstTest() {
-        assertThat(1).isEqualTo(42);
+        assertThat(1).isEqualTo(1);
+    }
+
+    @Test
+    public void cashCardSerializationTest() throws IOException {
+        CashCard cashCard = new CashCard(99L, 123.45);
+
+        assertThat(json.write(cashCard)).isStrictlyEqualToJson("expected.json");
+
+        assertThat(json.write(cashCard)).hasJsonPathNumberValue("@.id");
+        assertThat(json.write(cashCard)).extractingJsonPathNumberValue("@.id")
+            .isEqualTo(99);
+
+        assertThat(json.write(cashCard)).hasJsonPathNumberValue("@.amount");
+        assertThat(json.write(cashCard)).extractingJsonPathNumberValue("@.amount")
+            .isEqualTo(123.45);
+    }
+
+    @Test
+    public void cashCardDeserializationTest() throws IOException {
+        String expected = """
+                {
+                    "id":1000,
+                    "amount":67.89
+                }
+                """;
+
+        assertThat(json.parse(expected)).isEqualTo(new CashCard(1000L, 67.89));
+
+        assertThat(json.parseObject(expected).id()).isEqualTo(1000);
+        assertThat(json.parseObject(expected).amount()).isEqualTo(67.89);
     }
 }
diff --git a/src/test/resources/djmil/cashcard/expected.json b/src/test/resources/djmil/cashcard/expected.json
new file mode 100644
index 0000000..82eacd0
--- /dev/null
+++ b/src/test/resources/djmil/cashcard/expected.json
@@ -0,0 +1,4 @@
+{
+    "id": 99,
+    "amount": 123.45
+}
\ No newline at end of file