eth/solidity: add solidity compiler bindings (#66)

* ci: install solidity compiler solc

* eth/solidity: add solidity compiler bindings

* eth/solidity: add tests and test contracts

* docs: update readme

* eth/solidity: fix error message

* eth/solidity: improve extension handling

* eth/solidity: test deploying a deposit contract

* spec: run rufo

* If read.length is greater than 8192, call recvmsg one more time to extract

Not yet known if this is a Mac OS specific problem.

* Use end_with?

* client/ipc: loop socket receive buffers until they close

Co-authored-by: q9f <q9f@users.noreply.github.com>
Co-authored-by: Yuta Kurotaki <yuta.kurotaki@gmail.com>

.github/workflows/spec.yml

@@ -29,13 +29,13 @@ jobs:
     - name: MacOs Dependencies
       run: |
         brew tap ethereum/ethereum
-        brew install --verbose pkg-config automake autogen ethereum
+        brew install --verbose pkg-config automake autogen ethereum solidity
       if: startsWith(matrix.os, 'macOS')
     - name: Ubuntu Dependencies
       run: |
         sudo add-apt-repository -y ppa:ethereum/ethereum
         sudo apt-get update
-        sudo apt-get install ethereum
+        sudo apt-get install ethereum solc
       if: startsWith(matrix.os, 'Ubuntu')
     - name: Run Geth
       run: |

README.md

@@ -28,9 +28,10 @@ What you get:
 - [x] ABI-Encoder and Decoder (including type parser)
 - [x] RLP-Encoder and Decoder (including sedes)
 - [x] RPC-Client (IPC/HTTP) for Execution-Layer APIs
+- [x] Solidity bindings (compile contracts from Ruby)
 
 Soon (TM):
-- [ ] Smart Contracts and Solidity Support
+- [ ] Smart Contract Support
 - [ ] EIP-1271 Smart-Contract Authentification
 - [ ] HD-Wallets (BIP-32) and Mnemonics (BIP-39)
 
@@ -44,6 +45,7 @@ Contents:
   - [2.5. Ethereum ABI Encoder and Decoder](#25-ethereum-abi-encoder-and-decoder)
   - [2.6. Ethereum RLP Encoder and Decoder](#26-ethereum-rlp-encoder-and-decoder)
   - [2.7. Ethereum RPC-Client](#27-ethereum-rpc-client)
+  - [2.8 Solidity Compiler Bindings](#28-solidity-compiler-bindings)
 - [3. Documentation](#3-documentation)
 - [4. Testing](#4-testing)
 - [5. Contributing](#5-contributing)
@@ -229,6 +231,28 @@ cli.get_nonce cli.eth_coinbase["result"]
 
 Check out `Eth::Api` for a list of supported RPC-APIs or consult the [Documentation](https://q9f.github.io/eth.rb/) for more details.
 
+### 2.8 Solidity Compiler Bindings
+Link a system-level Solidity compiler (`solc`) to your Ruby library and compile contracts.
+
+```ruby
+solc = Eth::Solidity.new
+# => #<Eth::Solidity:0x000055f05040c6d0 @compiler="/usr/bin/solc">
+contract = solc.compile "spec/fixtures/contracts/greeter.sol"
+# => {"Greeter"=>
+#   {"abi"=>
+#     [{"inputs"=>[{"internalType"=>"string", "name"=>"message", "type"=>"string"}], "stateMutability"=>"nonpayable", "type"=>"constructor"},
+#      {"inputs"=>[], "name"=>"greet", "outputs"=>[{"internalType"=>"string", "name"=>"", "type"=>"string"}], "stateMutability"=>"view", "type"=>"function"},
+#      {"inputs"=>[], "name"=>"kill", "outputs"=>[], "stateMutability"=>"nonpayable", "type"=>"function"}],
+#    "bin"=>
+#     "6080604052348015...6c634300080c0033"},
+#  "Mortal"=>
+#   {"abi"=>[{"inputs"=>[], "stateMutability"=>"nonpayable", "type"=>"constructor"}, {"inputs"=>[], "name"=>"kill", "outputs"=>[], "stateMutability"=>"nonpayable", "type"=>"function"}],
+#    "bin"=>
+#     "6080604052348015...6c634300080c0033"}}
+```
+
+The `contract["Greeter"]["bin"]` could be directly used to deploy the contract as `Eth::Tx` payload. Check out the [Documentation](https://q9f.github.io/eth.rb/) for more details.
+
 ## 3. Documentation
 The documentation can be found at: https://q9f.github.io/eth.rb
 

lib/eth.rb

@@ -29,6 +29,7 @@ module Eth
 require "eth/key"
 require "eth/rlp"
 require "eth/signature"
+require "eth/solidity"
 require "eth/tx"
 require "eth/unit"
 require "eth/util"

lib/eth/client/ipc.rb

@@ -40,6 +40,9 @@ def send(payload)
       socket = UNIXSocket.new(@path)
       socket.puts(payload)
       read = socket.recvmsg(nil)[0]
+      until read.end_with?("\n")
+        read = read << socket.recvmsg(nil)[0]
+      end
       socket.close
       return read
     end

lib/eth/solidity.rb

@@ -0,0 +1,75 @@
+# Copyright (c) 2016-2022 The Ruby-Eth Contributors
+#
+# 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.
+
+require "open3"
+
+# Provides the {Eth} module.
+module Eth
+
+  # Class to create {Solidity} compiler bingings for Ruby.
+  class Solidity
+
+    # Provides a Compiler Error in case the contract does not compile.
+    class CompilerError < StandardError; end
+
+    # Solidity compiler binary path.
+    attr_reader :compiler
+
+    # Instantiates a Solidity `solc` system compiler binding that can be
+    # used to compile Solidity contracts.
+    def initialize
+
+      # Currently only supports `solc`.
+      solc = get_compiler_path
+      raise SystemCallError, "Unable to find the solc compiler path!" if solc.nil?
+      @compiler = solc
+    end
+
+    # Use the bound Solidity executable to compile the given contract.
+    #
+    # @param contract [String] path of the contract to compile.
+    # @return [Array] JSON containing the compiled contract and ABI for all contracts.
+    def compile(contract)
+      raise Errno::ENOENT, "Contract file not found: #{contract}" unless File.exist? contract
+      command = "#{@compiler} --optimize --combined-json bin,abi #{contract}"
+      output, error, status = Open3.capture3 command
+      raise SystemCallError, "Unable to run solc compiler!" if status.exitstatus === 127
+      raise CompilerError, error unless status.success?
+      json = JSON.parse output
+      result = {}
+      json["contracts"].each do |key, value|
+        _file, name = key.split ":"
+        result[name] = {}
+        result[name]["abi"] = value["abi"]
+        result[name]["bin"] = value["bin"]
+      end
+      return result
+    end
+
+    private
+
+    # Tries to find a system executable path for the given compiler binary name.
+    def get_compiler_path(name = "solc")
+      extensions = [""]
+      extensions = ENV["PATHEXT"].split(";") unless ENV["PATHEXT"].nil?
+      ENV["PATH"].split(File::PATH_SEPARATOR).each do |path|
+        extensions.each do |ext|
+          executable = File.join path, "#{name}#{ext}"
+          return executable if File.executable? executable and !File.directory? executable
+        end
+      end
+      return nil
+    end
+  end
+end

spec/eth/solidity_spec.rb

@@ -0,0 +1,64 @@
+require "spec_helper"
+
+describe Solidity do
+  it "finds a solc compiler" do
+
+    # This fails if no `solc` is in the $PATH.
+    expect(Solidity.new).to be
+  end
+
+  subject(:solc) { Solidity.new }
+
+  it "compiles the dummy contract" do
+    contract = "#{Dir.pwd}/spec/fixtures/contracts/dummy.sol"
+    result = solc.compile contract
+    expect(result.keys).to eq ["Dummy"]
+    expect(result["Dummy"]["abi"]).to eq JSON.parse '[{"inputs":[],"name":"get","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"uint256","name":"x","type":"uint256"}],"name":"set","outputs":[],"stateMutability":"nonpayable","type":"function"}]'
+    expect(result["Dummy"]["bin"]).to start_with "6080604052348015600f57600080fd5b5060"
+  end
+
+  it "compiles the greeter contract" do
+    contract = "#{Dir.pwd}/spec/fixtures/contracts/greeter.sol"
+    result = solc.compile contract
+    expect(result.keys).to eq ["Greeter", "Mortal"]
+    expect(result["Mortal"]["abi"]).to eq JSON.parse '[{"inputs":[],"stateMutability":"nonpayable","type":"constructor"},{"inputs":[],"name":"kill","outputs":[],"stateMutability":"nonpayable","type":"function"}]'
+    expect(result["Greeter"]["abi"]).to eq JSON.parse '[{"inputs":[{"internalType":"string","name":"message","type":"string"}],"stateMutability":"nonpayable","type":"constructor"},{"inputs":[],"name":"greet","outputs":[{"internalType":"string","name":"","type":"string"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"kill","outputs":[],"stateMutability":"nonpayable","type":"function"}]'
+    expect(result["Mortal"]["bin"]).to start_with "6080604052348015600f57600080fd5b5060"
+    expect(result["Greeter"]["bin"]).to start_with "608060405234801561001057600080fd5b5060"
+  end
+
+  it "deploys an ethereum-consensus deposit contract" do
+    geth = Client.create "/tmp/geth.ipc"
+    contract = "#{Dir.pwd}/spec/fixtures/contracts/deposit.sol"
+    result = solc.compile contract
+    expect(result["DepositContract"]).to be
+    payload = result["DepositContract"]["bin"]
+    expect(payload).to start_with "60806040523480156200001157600080fd5b5060"
+    params = {
+      from: geth.default_account,
+      priority_fee: 0,
+      max_gas_fee: Unit::GWEI,
+      gas_limit: Tx.estimate_intrinsic_gas(payload),
+      data: payload,
+    }
+    deploy = geth.eth_send_transaction(params)
+    hash = deploy["result"]
+    expect(hash).to start_with "0x"
+    geth.wait_for_tx hash
+    receipt = geth.eth_get_transaction_receipt hash
+    expect(receipt["result"]).to be
+    address = receipt["result"]["contractAddress"]
+    expect(address).to be
+    expect { Address.new address }.not_to raise_error
+  end
+
+  it "handles file-system errors" do
+    contract = "#{Dir.pwd}/spec/fixtures/contracts/null.sol"
+    expect { solc.compile contract }.to raise_error Errno::ENOENT, /No such file or directory - Contract file not found:/
+  end
+
+  it "handles compiler errors" do
+    contract = "#{Dir.pwd}/spec/fixtures/contracts/error.sol"
+    expect { solc.compile contract }.to raise_error Solidity::CompilerError, /Error: Identifier not found or not unique./
+  end
+end