Support for Generation of Custom Error type

CHANGELOG.md

@@ -15,6 +15,7 @@ See [Conventional Commits](https://conventionalcommits.org) for commit guideline
 
 * bump snapshot version to 4.13.1 [#2160](https://github.com/hyperledger-web3j/web3j/pull/2160)
 * Upgrade to https://github.com/Consensys/tuweni/releases/tag/v2.7.0 [#2170](https://github.com/LFDT-web3j/web3j/pull/2170)
+* Add support for code generation of custom error type introduced with `solidity v0.8.4` [#2173](https://github.com/LFDT-web3j/web3j/pull/2173)
 
 
 ### BREAKING CHANGES

abi/src/main/java/org/web3j/abi/CustomErrorEncoder.java

@@ -0,0 +1,53 @@
+/*
+ * Copyright 2019 Web3 Labs Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+ * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations under the License.
+ */
+package org.web3j.abi;
+
+import java.util.List;
+import java.util.stream.Collectors;
+
+import org.web3j.abi.datatypes.CustomError;
+import org.web3j.abi.datatypes.Type;
+import org.web3j.crypto.Hash;
+import org.web3j.utils.Numeric;
+
+/**
+ * Ethereum custom error encoding. Further limited details are available <a
+ * href="https://docs.soliditylang.org/en/develop/abi-spec.html#errors">here</a>.
+ */
+public class CustomErrorEncoder {
+
+    private CustomErrorEncoder() {}
+
+    public static String encode(CustomError error) {
+        return calculateSignatureHash(buildErrorSignature(error.getName(), error.getParameters()));
+    }
+
+    static <T extends Type> String buildErrorSignature(
+            String errorName, List<TypeReference<T>> parameters) {
+
+        StringBuilder result = new StringBuilder();
+        result.append(errorName);
+        result.append("(");
+        String params =
+                parameters.stream().map(Utils::getTypeName).collect(Collectors.joining(","));
+        result.append(params);
+        result.append(")");
+        return result.toString();
+    }
+
+    public static String calculateSignatureHash(String errorSignature) {
+        byte[] input = errorSignature.getBytes();
+        byte[] hash = Hash.sha3(input);
+        return Numeric.toHexString(hash);
+    }
+}

abi/src/main/java/org/web3j/abi/datatypes/CustomError.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright 2019 Web3 Labs Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+ * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations under the License.
+ */
+package org.web3j.abi.datatypes;
+
+import java.util.List;
+
+import org.web3j.abi.TypeReference;
+
+import static org.web3j.abi.Utils.convert;
+
+/** CustomError wrapper type. */
+public class CustomError {
+    private String name;
+    private List<TypeReference<Type>> parameters;
+
+    public CustomError(String name, List<TypeReference<?>> parameters) {
+        this.name = name;
+        this.parameters = convert(parameters);
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public List<TypeReference<Type>> getParameters() {
+        return parameters;
+    }
+}

abi/src/test/java/org/web3j/abi/CustomErrorEncoderTest.java

@@ -0,0 +1,90 @@
+/*
+ * Copyright 2019 Web3 Labs Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+ * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations under the License.
+ */
+package org.web3j.abi;
+
+import java.util.Arrays;
+import java.util.List;
+
+import org.junit.jupiter.api.Test;
+
+import org.web3j.abi.datatypes.Address;
+import org.web3j.abi.datatypes.CustomError;
+import org.web3j.abi.datatypes.DynamicArray;
+import org.web3j.abi.datatypes.Utf8String;
+import org.web3j.abi.datatypes.generated.Uint256;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.web3j.abi.Utils.convert;
+
+public class CustomErrorEncoderTest {
+    @Test
+    public void testCalculateSignatureHash() {
+        assertEquals(
+                CustomErrorEncoder.calculateSignatureHash("InvalidAccess(address,string,uint256)"),
+                ("0xcb5157bf1b439b9573ea7a95f7c00cc33f832ed728345c2bd29146ce58bbab57"));
+
+        assertEquals(
+                CustomErrorEncoder.calculateSignatureHash("RandomError(address[],bytes)"),
+                ("0xbf37b77ddf0fbbf29ee6a3ebda3d177c2d438123b10571806c57958230d9f905"));
+    }
+
+    @Test
+    public void testEncode() {
+        CustomError error =
+                new CustomError(
+                        "InvalidAccess",
+                        Arrays.<TypeReference<?>>asList(
+                                new TypeReference<Address>() {},
+                                new TypeReference<Utf8String>() {},
+                                new TypeReference<Uint256>() {}));
+
+        assertEquals(
+                CustomErrorEncoder.encode(error),
+                "0xcb5157bf1b439b9573ea7a95f7c00cc33f832ed728345c2bd29146ce58bbab57");
+    }
+
+    @Test
+    public void testBuildErrorSignature() {
+        List<TypeReference<?>> parameters =
+                Arrays.<TypeReference<?>>asList(
+                        new TypeReference<Address>() {},
+                        new TypeReference<Utf8String>() {},
+                        new TypeReference<Uint256>() {});
+
+        assertEquals(
+                "InvalidAccess(address,string,uint256)",
+                CustomErrorEncoder.buildErrorSignature("InvalidAccess", convert(parameters)));
+    }
+
+    @Test
+    void testBuildErrorSignatureWithDynamicStructs() {
+        List<TypeReference<?>> parameters =
+                Arrays.asList(
+                        new TypeReference<AbiV2TestFixture.Nazz>() {},
+                        new TypeReference<AbiV2TestFixture.Foo>() {});
+
+        assertEquals(
+                "DynamicStructError((((string,string)[])[],uint256),(string,string))",
+                CustomErrorEncoder.buildErrorSignature("DynamicStructError", convert(parameters)));
+    }
+
+    @Test
+    void testBuildErrorSignatureWithDynamicArrays() {
+        List<TypeReference<?>> parameters =
+                Arrays.asList(new TypeReference<DynamicArray<AbiV2TestFixture.Nazz>>() {});
+
+        assertEquals(
+                "DynamicArrayError((((string,string)[])[],uint256)[])",
+                EventEncoder.buildMethodSignature("DynamicArrayError", convert(parameters)));
+    }
+}

abi/src/test/java/org/web3j/abi/datatypes/CustomErrorTest.java

@@ -0,0 +1,43 @@
+/*
+ * Copyright 2020 Web3 Labs Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+ * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations under the License.
+ */
+package org.web3j.abi.datatypes;
+
+import java.util.Arrays;
+import java.util.Iterator;
+import java.util.List;
+
+import org.junit.jupiter.api.Test;
+
+import org.web3j.abi.TypeReference;
+import org.web3j.abi.datatypes.generated.Uint256;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class CustomErrorTest {
+
+    @Test
+    public void testCreation() {
+
+        List<TypeReference<?>> parameters =
+                Arrays.<TypeReference<?>>asList(
+                        new TypeReference<Address>() {}, new TypeReference<Uint256>() {});
+        CustomError event = new CustomError("MyError", parameters);
+
+        assertEquals(event.getName(), "MyError");
+
+        Iterator<TypeReference<?>> expectedParameter = parameters.iterator();
+        for (TypeReference<?> actualParameter : event.getParameters()) {
+            assertEquals(expectedParameter.next(), actualParameter);
+        }
+    }
+}