Added function signature helpers to Decoder.java

wkennedy · Jul 16, 2024 · faf84e6 · faf84e6
1 parent 87a3c5b
commit faf84e6
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diff --git a/src/main/java/com/github/wkennedy/abi/Decoder.java b/src/main/java/com/github/wkennedy/abi/Decoder.java
@@ -228,6 +228,22 @@ public List<DecodedLog> decodeLogs(String data) {
         return decodeLogs(logs);
     }
 
+    public static String getFunctionSignature(byte[] data) {
+        byte[] methodBytes = Arrays.copyOf(data, 4);
+        return HEX_PREFIX + Hex.encodeHexString(methodBytes);
+    }
+
+    public static String getFunctionSignature(String data) {
+        String noPrefix = data.replaceFirst(HEX_PREFIX, "");
+        byte[] decodedDataInBytes;
+        try {
+            decodedDataInBytes = Hex.decodeHex(noPrefix.toUpperCase());
+            return getFunctionSignature(decodedDataInBytes);
+        } catch (DecoderException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
     private Log[] fromJson(String data) {
         try {
             return objectMapper.readValue(data, Log[].class);

diff --git a/src/test/java/com/github/wkennedy/abi/DecoderTest.java b/src/test/java/com/github/wkennedy/abi/DecoderTest.java
@@ -177,6 +177,11 @@ public void testDecodeFunctionTupleContainingDynamicTypes() throws IOException {
 //        assertEquals(DecodedFunctions.MULTICALL, decodedFunction.getName());
     }
 
+    @Test
+    public void testGetFunctionSignature() {
+        String functionSignature = Decoder.getFunctionSignature("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");
+        assertEquals("0x73b80d49777f0c32d45a0a5a7c3487eb9e8da2c93922540c260cdafc3e81a165", functionSignature);
+    }
 
     @Test
     public void testDecodeMulticall() throws IOException {