Fix constructor input decoding to preserve full ABI payload

[Copilot]

ContractCodec.decodeConstructorInput(abi, bin, input) was decoding constructor args through the method-input path, which incorrectly drops the first 4 bytes as if a function selector were present. Constructor calldata has no selector after the bytecode, so the first parameter was truncated and decoded incorrectly.

• Constructor decode path

  • Route decodeConstructorInput(...) through direct ABI payload decoding instead of decodeMethodAndGetInputObject(...).
  • This aligns the object-returning path with decodeConstructorInputToString(...), which already decodes the full constructor parameter bytes.

• Regression coverage

  • Add a focused constructor round-trip test with actual parameters (uint256, string).
  • Verify decodeConstructorInput(...) now returns the same values represented by the already-correct string decode path.

• Behavioral impact

  • Method input decoding remains unchanged.
  • Constructor decoding now preserves the full encoded parameter payload instead of stripping a non-existent selector.

public List<Object> decodeConstructorInput(String abi, String bin, String input)
        throws ContractCodecException {
    String paramsInput = StringUtils.substringAfter(input, bin);
    if (paramsInput.isEmpty()) {
        return new ArrayList<>();
    }

    ContractABIDefinition contractABIDefinition = this.abiDefinitionFactory.loadABI(abi);
    ABIDefinition abiDefinition = contractABIDefinition.getConstructor();
    ABIObject inputObject = ABIObjectFactory.createInputObject(abiDefinition);
    return ContractCodecTools.decodeJavaObject(inputObject, paramsInput, isWasm);
}

[Copilot]

Pull request overview

Fixes ContractCodec.decodeConstructorInput(...) to decode constructor calldata correctly by decoding the full ABI-encoded parameter payload (constructor input has no 4-byte selector to strip), aligning behavior with decodeConstructorInputToString(...).

Changes:

• Route decodeConstructorInput(...) through direct ABI payload decoding (instead of method-input decoding that strips 4 bytes).
• Add a regression test that round-trips constructor params (uint256, string) and asserts object/string decode consistency.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
src/main/java/org/fisco/bcos/sdk/v3/codec/ContractCodec.java	Updates constructor input decoding to avoid dropping the first 4 bytes and decode full parameter payload.
src/test/java/org/fisco/bcos/sdk/v3/test/codec/ABICodecTest.java	Adds a focused constructor decode test with parameters to prevent regressions.

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

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