boot/modules/acquiring/src/test/java/com/klaro/acquirecore/acquiring/codec/MessageCodecTest.java

@@ -0,0 +1,70 @@
+package com.klaro.acquirecore.acquiring.codec;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class MessageCodecTest {
+
+    private MessageCodec codec;
+
+    @BeforeEach
+    void setUp() {
+        codec = new MessageCodec();
+    }
+
+    @Test
+    void unpack_validMessage_parsesCorrectly() {
+        // given
+        String raw = "MSGT123456789012TX01MER00001    1234567890123456789000000012340A12345678ETX";
+        byte[] rawMessage = raw.getBytes();
+
+        // when
+        ParsedMessage parsed = codec.unpack(rawMessage);
+
+        // then
+        assertEquals("MSGT", parsed.getMessageType());
+        assertEquals("123456789012", parsed.getTxId());
+        assertEquals("TX01", parsed.getTxCode());
+        assertEquals("MER00001", parsed.getMerchantId());
+        assertEquals("12345678901234567890", parsed.getCardNumber());
+        assertEquals("0000001234", parsed.getAmount());
+        assertEquals("A12345678", parsed.getApprovalCode());
+        assertEquals("ETX", parsed.getTrailer());
+    }
+
+    @Test
+    void unpack_nullMessage_throwsException() {
+        assertThrows(IllegalArgumentException.class, () -> codec.unpack(null));
+    }
+
+    @Test
+    void unpack_shortMessage_throwsException() {
+        byte[] shortMessage = new byte[10];
+        assertThrows(IllegalArgumentException.class, () -> codec.unpack(shortMessage));
+    }
+
+    @Test
+    void pack_validMessage_packsCorrectly() {
+        // given
+        ParsedMessage parsed = new ParsedMessage();
+        parsed.setMessageType("MSGT");
+        parsed.setTxId("123456789012");
+        parsed.setTxCode("TX01");
+        parsed.setMerchantId("MER00001");
+        parsed.setCardNumber("12345678901234567890");
+        parsed.setAmount("0000001234");
+        parsed.setApprovalCode("A12345678");
+
+        // when
+        byte[] packed = codec.pack(parsed);
+
+        // then
+        assertNotNull(packed);
+        assertTrue(packed.length > 0);
+        String packedStr = new String(packed);
+        assertTrue(packedStr.startsWith("MSGT"));
+        assertTrue(packedStr.endsWith("ETX"));
+    }
+}