Improve Js5MasterIndex test coverage

Signed-off-by: Graham <gpe@openrs2.org>

cache/src/test/kotlin/org/openrs2/cache/Js5MasterIndexTest.kt

@@ -1,11 +1,20 @@
 package org.openrs2.cache
 
+import io.netty.buffer.ByteBufAllocator
+import io.netty.buffer.Unpooled
+import org.openrs2.buffer.use
 import java.nio.file.Paths
 import kotlin.test.Test
 import kotlin.test.assertEquals
 
 object Js5MasterIndexTest {
     private val ROOT = Paths.get(FlatFileStoreTest::class.java.getResource("master-index").toURI())
+    private val encoded = byteArrayOf(0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 0, 2, 0, 0, 0, 5, 0, 0, 0, 4)
+    private val decoded = Js5MasterIndex(mutableListOf(
+        Js5MasterIndex.Entry(0, 1),
+        Js5MasterIndex.Entry(2, 3),
+        Js5MasterIndex.Entry(4, 5)
+    ))
 
     @Test
     fun testCreate() {
@@ -23,4 +32,23 @@ object Js5MasterIndexTest {
             Js5MasterIndex.Entry(0xAA55AA55.toInt(), -627983571)
         )), index)
     }
+
+    @Test
+    fun testRead() {
+        Unpooled.wrappedBuffer(encoded).use { buf ->
+            val index = Js5MasterIndex.read(buf)
+            assertEquals(decoded, index)
+        }
+    }
+
+    @Test
+    fun testWrite() {
+        ByteBufAllocator.DEFAULT.buffer().use { actual ->
+            decoded.write(actual)
+
+            Unpooled.wrappedBuffer(encoded).use { expected ->
+                assertEquals(expected, actual)
+            }
+        }
+    }
 }