feat(HashingAlgorithm): get metadata, closes #101

richardschneider · Aug 17, 2019 · 6f5ef80 · 6f5ef80
1 parent 76ca1a4
commit 6f5ef80
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Showing 2 changed files with 47 additions and 1 deletion.
diff --git a/src/Registry/HashingAlgorithm.cs b/src/Registry/HashingAlgorithm.cs
@@ -237,10 +237,28 @@ public static IEnumerable<HashingAlgorithm> All
         ///   When <paramref name="name"/> is not registered.
         /// </exception>
         public static HashAlgorithm GetAlgorithm(string name)
+        {
+            return GetAlgorithmMetadata(name).Hasher();
+        }
+
+        /// <summary>
+        ///   Gets the metadata with the specified IPFS multi-hash name.
+        /// </summary>
+        /// <param name="name">
+        ///   The name of a hashing algorithm, see <see href="https://github.com/multiformats/multicodec/blob/master/table.csv"/>
+        ///   for IPFS defined names.
+        /// </param>
+        /// <returns>
+        ///   The metadata associated with the hashing <paramref name="name"/>.
+        /// </returns>
+        /// <exception cref="KeyNotFoundException">
+        ///   When <paramref name="name"/> is not registered.
+        /// </exception>
+        public static HashingAlgorithm GetAlgorithmMetadata(string name)
         {
             try
             {
-                return HashingAlgorithm.Names[name].Hasher();
+                return HashingAlgorithm.Names[name];
             }
             catch (KeyNotFoundException)
             {

diff --git a/test/Registry/HashingAlgorithmTest.cs b/test/Registry/HashingAlgorithmTest.cs
@@ -31,6 +31,34 @@ public void GetHasher_Unknown()
             ExceptionAssert.Throws<KeyNotFoundException>(() => HashingAlgorithm.GetAlgorithm("unknown"));
         }
 
+        [TestMethod]
+        public void GetMetadata()
+        {
+            var info = HashingAlgorithm.GetAlgorithmMetadata("sha3-256");
+            Assert.IsNotNull(info);
+            Assert.AreEqual("sha3-256", info.Name);
+            Assert.AreEqual(0x16, info.Code);
+            Assert.AreEqual(256 /8, info.DigestSize);
+            Assert.IsNotNull(info.Hasher);
+        }
+
+        [TestMethod]
+        public void GetMetadata_Unknown()
+        {
+            ExceptionAssert.Throws<KeyNotFoundException>(() => HashingAlgorithm.GetAlgorithmMetadata("unknown"));
+        }
+
+        [TestMethod]
+        public void GetMetadata_Alias()
+        {
+            var info = HashingAlgorithm.GetAlgorithmMetadata("id");
+            Assert.IsNotNull(info);
+            Assert.AreEqual("identity", info.Name);
+            Assert.AreEqual(0, info.Code);
+            Assert.AreEqual(0, info.DigestSize);
+            Assert.IsNotNull(info.Hasher);
+        }
+
         [TestMethod]
         public void HashingAlgorithm_Bad_Name()
         {