more tests

Added cid.toBytes()

Author: ianopolous

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

@@ -47,13 +47,13 @@ public Cid(long version, Codec codec, Multihash hash) {
         this.hash = hash;
     }
 
-    public byte[] toBytesV0() {
+    private byte[] toBytesV0() {
         return hash.toBytes();
     }
 
     private static  final int MAX_VARINT_LEN64 = 10;
 
-    public byte[] toBytesV1() {
+    private byte[] toBytesV1() {
         byte[] hashBytes = hash.toBytes();
         byte[] res = new byte[2 * MAX_VARINT_LEN64 + hashBytes.length];
         int index = putUvarint(res, 0, version);
@@ -62,6 +62,14 @@ public byte[] toBytesV1() {
         return Arrays.copyOfRange(res, 0, index + hashBytes.length);
     }
 
+    public byte[] toBytes() {
+        if (version == 0)
+            return toBytesV0();
+        else if (version == 1)
+            return toBytesV1();
+        throw new IllegalStateException("Unknown cid version: " + version);
+    }
+
     @Override
     public String toString() {
         if (version == 0) {
@@ -113,7 +121,7 @@ public static Cid decode(String v) throws IOException {
         return cast(data);
     }
 
-    private static Cid cast(byte[] data) throws IOException {
+    public static Cid cast(byte[] data) throws IOException {
         if (data.length == 34 && data[0] == 0x18 && data[1] == 32)
             return buildCidV0(new Multihash(data));
 

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

@@ -1,15 +1,17 @@
 package io.ipfs.cid;
 
+import io.ipfs.multihash.*;
 import org.junit.*;
 import io.ipfs.multibase.*;
 
 import java.io.*;
+import java.security.*;
 import java.util.*;
 
 public class CidTest {
 
     @Test
-    public void stringTest() throws IOException {
+    public void validStrings() throws IOException {
         List<String> examples = Arrays.asList(
                 "QmPZ9gcCEpqKTo6aq61g2nXGUhM4iCL3ewB6LDXZCtioEB",
                 "QmatmE9msSfkKxoffpHwNLNKgwZG8eT9Bud6YoPab52vpy",
@@ -22,4 +24,49 @@ public void stringTest() throws IOException {
                 throw new IllegalStateException("Incorrect cid string! " + example + " => " + encoded);
         }
     }
+
+    @Test
+    public void emptyStringShouldFail() throws IOException {
+        try {
+            Cid cid = Cid.decode("");
+            throw new RuntimeException();
+        } catch (IllegalStateException e) {}
+    }
+
+    @Test
+    public void basicMarshalling() throws Exception {
+        MessageDigest hasher = MessageDigest.getInstance("SHA-512");
+        byte[] hash = hasher.digest("TEST".getBytes());
+        Multihash mhash = new Multihash(Multihash.Type.sha2_512, hash);
+
+        Cid cid = new Cid(1, Cid.Codec.Raw, mhash);
+        byte[] data = cid.toBytes();
+
+        Cid cast = Cid.cast(data);
+        Assert.assertTrue("Invertible serialization", cast.equals(cid));
+
+        Cid fromString = Cid.decode(cid.toString());
+        Assert.assertTrue("Invertible toString", fromString.equals(cid));
+    }
+
+    @Test
+    public void version0Handling() throws Exception {
+        String hashString = "QmPZ9gcCEpqKTo6aq61g2nXGUhM4iCL3ewB6LDXZCtioEB";
+        Cid cid = Cid.decode(hashString);
+
+        Assert.assertTrue("version 0", cid.version == 0);
+
+        Assert.assertTrue("Correct hash", cid.hash.toString().equals(hashString));
+
+        Assert.assertTrue("Correct toString", cid.toString().equals(hashString));
+    }
+
+    @Test
+    public void version0Error() throws Exception {
+        String invalidString = "QmdfTbBqBPQ7VNxZEYEj14VmRuZBkqFbiwReogJgS1zIII";
+        try {
+            Cid cid = Cid.decode(invalidString);
+            throw new RuntimeException();
+        } catch (IllegalStateException e) {}
+    }
 }