Added test and toString()

Author: ianopolous

src/main/java/io/ipfs/cid/Cid.java

@@ -62,6 +62,16 @@ public byte[] toBytesV1() {
         return Arrays.copyOfRange(res, 0, index + hashBytes.length);
     }
 
+    @Override
+    public String toString() {
+        if (version == 0) {
+            return hash.toString();
+        } else if (version == 1) {
+            return Multibase.encode(Multibase.Base.Base58BTC, toBytesV1());
+        }
+        throw new IllegalStateException("Unknown Cid version: " + version);
+    }
+
     @Override
     public boolean equals(Object o) {
         if (this == o) return true;

src/test/java/io/ipfs/cid/CidTest.java

@@ -2,19 +2,24 @@
 
 import org.junit.*;
 import io.ipfs.multibase.*;
+
+import java.io.*;
 import java.util.*;
 
 public class CidTest {
 
     @Test
-    public void base58Test() {
-        List<String> examples = Arrays.asList("QmPZ9gcCEpqKTo6aq61g2nXGUhM4iCL3ewB6LDXZCtioEB",
-                "QmatmE9msSfkKxoffpHwNLNKgwZG8eT9Bud6YoPab52vpy");
+    public void stringTest() throws IOException {
+        List<String> examples = Arrays.asList(
+                "QmPZ9gcCEpqKTo6aq61g2nXGUhM4iCL3ewB6LDXZCtioEB",
+                "QmatmE9msSfkKxoffpHwNLNKgwZG8eT9Bud6YoPab52vpy",
+                "zdpuAyvkgEDQm9TenwGkd5eNaosSxjgEYd8QatfPetgB1CdEZ"
+        );
         for (String example: examples) {
-            byte[] output = Base58.decode(example);
-            String encoded = Base58.encode(output);
-            if (!encoded.equals(encoded))
-                throw new IllegalStateException("Incorrect base58! " + example + " => " + encoded);
+            Cid cid = Cid.decode(example);
+            String encoded = cid.toString();
+            if (!encoded.equals(example))
+                throw new IllegalStateException("Incorrect cid string! " + example + " => " + encoded);
         }
     }
 }