Merge the develop branch to the master branch, preparation to v2.0.0-rc4

This update for the master branch contains the following set of changes:
  * [Improvement] Multi part contract verification in Etherscan and Blockscout (#35)
  * [Improvement] Robust way of using TransferSingle mint for first mint ever (#36)

.github/workflows/release.yml

@@ -5,7 +5,7 @@ on:
     types: [created]
 
 jobs:
-  flats:
+  source:
     runs-on: ubuntu-latest
     steps:
       - id: get_release
@@ -23,13 +23,22 @@ jobs:
           key: ${{ runner.os }}-node_modules-${{ hashFiles('**/yarn.lock') }}
       - run: yarn
         if: ${{ !steps.yarn-cache.outputs.cache-hit }}
-      - run: yarn flatten
-      - run: zip flats $(find flats -name '*.sol')
+      - run: yarn compile
+      - run: zip contracts $(find contracts -name '*.sol')
+      - run: zip artifacts $(find build -name '*.json')
       - uses: actions/[email protected]
         env:
           GITHUB_TOKEN: ${{ github.token }}
         with:
           upload_url: ${{ steps.get_release.outputs.upload_url }}
-          asset_path: flats.zip
-          asset_name: omnibridge-nft-contracts-flattened-${{ steps.get_release.outputs.tag_name }}.zip
+          asset_path: contracts.zip
+          asset_name: omnibridge-nft-contracts-${{ steps.get_release.outputs.tag_name }}.zip
+          asset_content_type: application/zip
+      - uses: actions/[email protected]
+        env:
+          GITHUB_TOKEN: ${{ github.token }}
+        with:
+          upload_url: ${{ steps.get_release.outputs.upload_url }}
+          asset_path: artifacts.zip
+          asset_name: omnibridge-nft-artifacts-${{ steps.get_release.outputs.tag_name }}.zip
           asset_content_type: application/zip

Dockerfile

@@ -9,9 +9,6 @@ COPY truffle-config.js truffle-config.js
 COPY ./contracts ./contracts
 RUN yarn compile
 
-COPY flatten.sh flatten.sh
-RUN yarn flatten
-
 FROM node:14
 
 WORKDIR /contracts
@@ -20,7 +17,6 @@ COPY package.json yarn.lock ./
 RUN yarn install --prod
 
 COPY --from=contracts /contracts/build ./build
-COPY --from=contracts /contracts/flats ./flats
 
 COPY deploy.sh deploy.sh
 COPY ./deploy ./deploy

Dockerfile.dev

@@ -9,9 +9,6 @@ COPY truffle-config.js truffle-config.js
 COPY ./contracts ./contracts
 RUN yarn compile
 
-COPY flatten.sh flatten.sh
-RUN yarn flatten
-
 COPY deploy.sh deploy.sh
 COPY ./deploy ./deploy
 COPY ./test ./test

contracts/tokens/ERC1155BridgeToken.sol

@@ -19,6 +19,8 @@ contract ERC1155BridgeToken is ERC1155, IBurnableMintableERC1155Token {
 
     address public bridgeContract;
 
+    bool private hasAlreadyMinted;
+
     constructor(
         string memory _name,
         string memory _symbol,
@@ -78,7 +80,26 @@ contract ERC1155BridgeToken is ERC1155, IBurnableMintableERC1155Token {
         uint256[] memory _tokenIds,
         uint256[] memory _values
     ) external override onlyBridge {
-        _mintBatch(_to, _tokenIds, _values, new bytes(0));
+        if (_tokenIds.length == 1 && _values.length == 1) {
+            _mint(_to, _tokenIds[0], _values[0], new bytes(0));
+        } else {
+            // Next few lines ensure that the first mint ever happened in his token contract will performed using TransferSingle event
+            // Otherwise, NFT marketplaces have issues with indexing bridged token data.
+            // On first mint ever (when hasAlreadyMinted is false), last token id from the list is minted using TransferSingle.
+            // All over tokens from the list are minted using TransferBatch event.
+            // All subsequent operations will always use TransferBatch for operations involving more than 1 token id.
+            if (!hasAlreadyMinted) {
+                require(_tokenIds.length > 1 && _tokenIds.length == _values.length);
+                uint256 len = _tokenIds.length - 1;
+                _mint(_to, _tokenIds[len], _values[len], new bytes(0));
+                assembly {
+                    mstore(_tokenIds, len) // _tokenIds.pop()
+                    mstore(_values, len) // _values.pop()
+                }
+            }
+            _mintBatch(_to, _tokenIds, _values, new bytes(0));
+        }
+        hasAlreadyMinted = true;
     }
 
     /**
@@ -149,6 +170,6 @@ contract ERC1155BridgeToken is ERC1155, IBurnableMintableERC1155Token {
             uint64 patch
         )
     {
-        return (1, 0, 1);
+        return (1, 1, 0);
     }
 }

deploy/VERIFICATION.md

@@ -0,0 +1,72 @@
+## Process
+
+Due to usage of `pragma abicoder v2;` in the contracts source code,
+it is not possible to verify contracts through flattened source files.
+
+Instead, two different approaches can be used for Etherscan and Blockscout explorers.
+
+## Verification in Etherscan/Bscscan
+
+The simplest semi-automated solution found so far is to use `truffle-plugin-verify` and the corresponding shell script.
+First, collect information about deployed contracts from the logs for the particular chain in the following format:
+
+Example of deployed contracts list in the Foreign chain:
+```
+EternalStorageProxy@0xEc05e3f4D845f0E39e33146395aCE5D35c01Fcc0
+ERC721BridgeToken@0xd880d9d42Fad3dcbe885F499AE15822ACBF1f1F8
+ERC1155BridgeToken@0xaa5cF36b6d97a709fccF3fd4BEa94dA9753d9cA4
+ForeignNFTOmnibridge@0x964C086398cba3c0BaE520bE900E660a84cA331c
+```
+
+Example of deployed contracts list in the Home chain:
+```
+EternalStorageProxy@0x2c0bF58cC87763783e35a625ff6a3e50d9E05337
+ERC721BridgeToken@0x714c7985B073b1177356560631A30D24F60f9241
+ERC1155BridgeToken@0xB2bf0271DB0d30090756A25B01be2698f3E5e556
+OwnedUpgradeabilityProxy@0x4dCD4Dd4096eab35611D496087ceF7DaF1D4E57C
+SelectorTokenGasLimitManager@0x783A53aC5ab27d24E83A0211e6Ff70c3705a5435
+HomeNFTOmnibridge@0xFF9c66898B706cd56d2dB9587aB597A000eC6ed6
+
+# If required:
+# NFTForwardingRulesManager@0x...
+```
+
+After that run the following command for source verification in Etherscan for foreign network:
+```bash
+deploy/verifyEtherscan.sh ForeignNFTOmnibridge@0x964C086398cba3c0BaE520bE900E660a84cA331c
+```
+
+Use `VERIFY_HOME=true` environment variable for verification in the home network:
+```bash
+VERIFY_HOME=true deploy/verifyEtherscan.sh HomeNFTOmnibridge@0xFF9c66898B706cd56d2dB9587aB597A000eC6ed6
+```
+
+## Verification in Blockscout
+
+In order to verify multi-file contract in Blockscout, it must support Sourcify integration (present in the xDAI instance).
+
+The list of actions is the following:
+1) Upload contracts sources and metadata to IPFS.
+2) Wait until Sourcify monitor will handle uploaded files and will automatically verify deployed contracts.
+3) Import sources to blockscout from Sourcify database.
+
+### Upload to IPFS
+
+Run the following in our terminal
+
+```bash
+node deploy/uploadToIPFS.js
+```
+
+You should see all compiled artifacts being uploaded sequentially, their hashes should be printed into the console.
+
+### Check that contracts are verified in Sourcify
+
+You can check if your contracts are verified by visiting https://sourcify.dev
+Select the corresponding chain, then enter your contract address.
+You should be able to see a green check sign at the top.
+
+### Import sources to Blockscout
+
+Go to the contract page of your contract in the Blockscout, click `Code`, then `Verify & Publish`, then `Sources and Metadata JSON file`.
+Upload any file from the `./build/contract/*.json`. It could be any artifact, it does not matter, since our sources are already present in the Sourcify database.

deploy/getChainId.js

@@ -0,0 +1,4 @@
+const Web3 = require('web3')
+
+const web3 = new Web3(process.env.RPC_URL)
+web3.eth.getChainId().then(console.log)

deploy/src/deploymentUtils.js

@@ -9,26 +9,15 @@ const {
   GAS_LIMIT_EXTRA,
   HOME_DEPLOYMENT_GAS_PRICE,
   FOREIGN_DEPLOYMENT_GAS_PRICE,
-  HOME_EXPLORER_URL,
-  FOREIGN_EXPLORER_URL,
-  HOME_EXPLORER_API_KEY,
-  FOREIGN_EXPLORER_API_KEY,
   DEPLOYMENT_ACCOUNT_PRIVATE_KEY,
 } = require('./web3')
-const verifier = require('./utils/verifier')
 
 async function deployContract(contractJson, args, { network, nonce }) {
   let web3
-  let apiUrl
-  let apiKey
   if (network === 'foreign') {
     web3 = web3Foreign
-    apiUrl = FOREIGN_EXPLORER_URL
-    apiKey = FOREIGN_EXPLORER_API_KEY
   } else {
     web3 = web3Home
-    apiUrl = HOME_EXPLORER_URL
-    apiKey = HOME_EXPLORER_API_KEY
   }
   const instance = new web3.eth.Contract(contractJson.abi)
   const result = instance
@@ -45,14 +34,6 @@ async function deployContract(contractJson, args, { network, nonce }) {
   instance.options.address = receipt.contractAddress
   instance.deployedBlockNumber = receipt.blockNumber
 
-  if (apiUrl) {
-    let constructorArguments
-    if (args.length) {
-      constructorArguments = result.substring(contractJson.bytecode.length)
-    }
-    await verifier({ artifact: contractJson, constructorArguments, address: receipt.contractAddress, apiUrl, apiKey })
-  }
-
   return instance
 }
 

deploy/uploadToIPFS.js

@@ -0,0 +1,41 @@
+const IPFS = require('ipfs-http-client')
+const shell = require('shelljs')
+const path = require('path')
+
+async function main() {
+  const ipfs = IPFS.create({
+    host: 'ipfs.infura.io',
+    port: 5001,
+    protocol: 'https',
+  })
+
+  const artifactPaths = shell.ls('./build/contracts/*.json')
+
+  console.log('Uploading sources & metadata to IPFS (Infura Gateway)...')
+  console.log('========================================================')
+
+  for (const p of artifactPaths) {
+    const artifact = require(path.join(process.cwd(), p))
+
+    console.log()
+    console.log(artifact.contractName)
+    console.log('-'.repeat(artifact.contractName.length))
+
+    const res1 = await ipfs.add(artifact.metadata)
+    console.log(`metadata: ${res1.path}`)
+
+    const res2 = await ipfs.add(artifact.source)
+    console.log(`source:   ${res2.path}`)
+  }
+
+  console.log()
+  console.log('Finished.')
+  console.log()
+}
+
+main()
+  .then(() => process.exit(0))
+  .catch((err) => {
+    console.log(err)
+    process.exit(1)
+  })