boot/modules/acquiring/src/test/java/com/klaro/acquirecore/acquiring/service/TxMessageCodecTest.java

@@ -0,0 +1,107 @@
+package com.klaro.acquirecore.acquiring.service;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.klaro.acquirecore.acquiring.dto.TxMessage;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import java.nio.charset.StandardCharsets;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class TxMessageCodecTest {
+
+    private TxMessageCodec codec;
+
+    @BeforeEach
+    void setUp() {
+        codec = new TxMessageCodec(new ObjectMapper());
+    }
+
+    @Test
+    void unpack_validJsonMessage_parsesCorrectly() {
+        // Given
+        String body = "{\"TXID\":\"TX001\",\"MERCHANTID\":\"M001\",\"TERMINALID\":\"T001\",\"AMOUNT\":\"10000\"}";
+        byte[] raw = buildRawMessage("HEADER", body);
+
+        // When
+        TxMessage msg = codec.unpack(raw);
+
+        // Then
+        assertEquals("TX001", msg.getTxId());
+        assertEquals("M001", msg.getMerchantId());
+        assertEquals("T001", msg.getTerminalId());
+        assertEquals("10000", msg.getAmount());
+    }
+
+    @Test
+    void unpack_delimitedMessage_parsesCorrectly() {
+        // Given
+        String body = "TXID=TX002|MERCHANTID=M002|TERMINALID=T002|AMOUNT=20000";
+        byte[] raw = buildRawMessage("HEADER", body);
+
+        // When
+        TxMessage msg = codec.unpack(raw);
+
+        // Then
+        assertEquals("TX002", msg.getTxId());
+        assertEquals("M002", msg.getMerchantId());
+        assertEquals("T002", msg.getTerminalId());
+        assertEquals("20000", msg.getAmount());
+    }
+
+    @Test
+    void unpack_tooShortMessage_throwsException() {
+        // Given
+        byte[] raw = "short".getBytes(StandardCharsets.ISO_8859_1);
+
+        // When/Then
+        assertThrows(IllegalArgumentException.class, () -> codec.unpack(raw));
+    }
+
+    @Test
+    void pack_unpackedMessage_producesValidBytes() {
+        // Given
+        TxMessage msg = new TxMessage();
+        msg.setTxId("TX003");
+        msg.setMerchantId("M003");
+        msg.setTerminalId("T003");
+        msg.setAmount("30000");
+        msg.setStatus("REQ");
+
+        // When
+        byte[] packed = codec.pack(msg);
+
+        // Then
+        assertNotNull(packed);
+        assertTrue(packed.length >= 20);
+
+        // Verify can unpack back
+        TxMessage unpacked = codec.unpack(packed);
+        assertEquals("TX003", unpacked.getTxId());
+        assertEquals("M003", unpacked.getMerchantId());
+    }
+
+    @Test
+    void unpack_packRoundTrip_preservesData() {
+        // Given
+        String body = "{\"TXID\":\"TX004\",\"MERCHANTID\":\"M004\",\"AMOUNT\":\"40000\",\"AUTHNO\":\"123456\"}";
+        byte[] raw = buildRawMessage("HEADER", body);
+
+        // When
+        TxMessage original = codec.unpack(raw);
+        byte[] repacked = codec.pack(original);
+        TxMessage roundTrip = codec.unpack(repacked);
+
+        // Then
+        assertEquals(original.getTxId(), roundTrip.getTxId());
+        assertEquals(original.getMerchantId(), roundTrip.getMerchantId());
+        assertEquals(original.getAmount(), roundTrip.getAmount());
+        assertEquals(original.getAuthNo(), roundTrip.getAuthNo());
+    }
+
+    private byte[] buildRawMessage(String header, String body) {
+        String hdr = String.format("%-20s", header);
+        return (hdr + body).getBytes(StandardCharsets.ISO_8859_1);
+    }
+}