Upgrade solidity and tests infrastructure

.github/workflows/push_checking.yml

@@ -6,14 +6,14 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        node-version: [12.x]
+        node-version: [20.x]
 
     steps:
       - name: Checkout
-        uses: 'actions/checkout@master'
+        uses: actions/checkout@v4
 
       - name: Set Node.js
-        uses: actions/setup-node@v1
+        uses: actions/setup-node@v4
         with:
           node-version: ${{ matrix.node-version }}
 
@@ -28,22 +28,19 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        node-version: [12.x]
+        node-version: [20.x]
 
     steps:
       - name: Checkout
-        uses: 'actions/checkout@master'
+        uses: actions/checkout@v4
 
       - name: Set Node.js
-        uses: actions/setup-node@v1
+        uses: actions/setup-node@v4
         with:
           node-version: ${{ matrix.node-version }}
 
       - name: Install dependencies
         run: npm install
 
-      - name: Install Truffle
-        run: npm install -g truffle
-
       - name: Run tests
         run: npm run test

.gitignore

@@ -1,12 +1,22 @@
-.idea/
-node_modules
+.idea
+.deps
 build
-coverage
-coverage.json
-/.coverage_artifacts/
-/.coverage_contracts/
-/coverageEnv/
-/coverageEnv/
-artifacts/
-cache/
-.env
+contracts/artifacts
+internal/rpc/contracts
+.deploys
+.states
+
+node_modules
+.env
+
+# solidity-coverage files
+/coverage
+/coverage.json
+
+# Hardhat files
+/cache
+/artifacts
+
+# TypeChain files
+/typechain
+/typechain-types

.prettierrc

@@ -0,0 +1,16 @@
+{
+  "printWidth": 120,
+  "singleQuote": true,
+  "trailingComma": "all",
+  "arrowParens": "avoid",
+  "overrides": [
+    {
+      "files": "*.sol",
+      "options": {
+        "singleQuote": false,
+        "quoteProps": "consistent"
+      }
+    }
+  ],
+  "plugins": ["prettier-plugin-solidity"]
+}

.solcover.js

@@ -1,3 +1,3 @@
 module.exports = {
-    skipFiles: ['common/ReentrancyGuard.sol', 'sfc/Migrations.sol']
+  skipFiles: ['common/ReentrancyGuard.sol', 'sfc/Migrations.sol'],
 };

Makefile

@@ -3,15 +3,19 @@ all: build
 
 .PHONY: build
 build:
-	docker run --rm --user $$(id -u):$$(id -g) -v $(PWD):/src -w /src node:16.19.1 bash -c \
-	    'export NPM_CONFIG_PREFIX=~; npm install --no-save; npm install --no-save [email protected]; npm run build'
+	docker run --rm --user $$(id -u):$$(id -g) -v $(PWD):/src -w /src node:20.17.0 bash -c \
+	    'export NPM_CONFIG_PREFIX=~; npm install --no-save; npx hardhat compile'
 
 .PHONY: checksum
 checksum:
 	for f in ./build/contracts/*.json; do echo -n "$$f "; jq -j .deployedBytecode $$f | shasum; done
 
 .PHONY: test
 test:
-	docker run --rm --user $$(id -u):$$(id -g) -v $(PWD):/src -w /src node:16.19.1 bash -c \
-	    'export NPM_CONFIG_PREFIX=~; npm install --no-save; npm install --no-save [email protected]; npm run test'
+	docker run --rm --user $$(id -u):$$(id -g) -v $(PWD):/src -w /src node:20.17.0 bash -c \
+	    'export NPM_CONFIG_PREFIX=~; npm install --no-save; npx hardhat test'
 
+.PHONY: workspace
+workspace:
+	docker run -t -i --rm --user $$(id -u):$$(id -g) -v $(PWD):/src -w /src node:20.17.0 bash -c \
+	    'export NPM_CONFIG_PREFIX=~; npm install --no-save; bash'

contracts/common/Decimal.sol

@@ -1,4 +1,5 @@
-pragma solidity ^0.5.0;
+// SPDX-License-Identifier: UNLICENSED
+pragma solidity ^0.8.9;
 
 library Decimal {
     // unit is used for decimals, e.g. 0.123456

contracts/common/Initializable.sol

@@ -1,5 +1,5 @@
-pragma solidity >=0.4.24 <0.7.0;
-
+// SPDX-License-Identifier: UNLICENSED
+pragma solidity ^0.8.9;
 
 /**
  * @title Initializable
@@ -14,49 +14,35 @@ pragma solidity >=0.4.24 <0.7.0;
  * because this is not dealt with automatically as with constructors.
  */
 contract Initializable {
-
-  /**
-   * @dev Indicates that the contract has been initialized.
-   */
-  bool private initialized;
-
-  /**
-   * @dev Indicates that the contract is in the process of being initialized.
-   */
-  bool private initializing;
-
-  /**
-   * @dev Modifier to use in the initializer function of a contract.
-   */
-  modifier initializer() {
-    require(initializing || isConstructor() || !initialized, "Contract instance has already been initialized");
-
-    bool isTopLevelCall = !initializing;
-    if (isTopLevelCall) {
-      initializing = true;
-      initialized = true;
+    /**
+     * @dev Indicates that the contract has been initialized.
+     */
+    bool private initialized;
+
+    /**
+     * @dev Indicates that the contract is in the process of being initialized.
+     */
+    bool private initializing;
+
+    /**
+     * @dev Modifier to use in the initializer function of a contract.
+     */
+    modifier initializer() {
+        require(initializing || !initialized, "Contract instance has already been initialized");
+
+        bool isTopLevelCall = !initializing;
+        if (isTopLevelCall) {
+            initializing = true;
+            initialized = true;
+        }
+
+        _;
+
+        if (isTopLevelCall) {
+            initializing = false;
+        }
     }
 
-    _;
-
-    if (isTopLevelCall) {
-      initializing = false;
-    }
-  }
-
-  /// @dev Returns true if and only if the function is running in the constructor
-  function isConstructor() private view returns (bool) {
-    // extcodesize checks the size of the code stored in an address, and
-    // address returns the current address. Since the code is still not
-    // deployed when running a constructor, any checks on its code size will
-    // yield zero, making it an effective way to detect if a contract is
-    // under construction or not.
-    address self = address(this);
-    uint256 cs;
-    assembly { cs := extcodesize(self) }
-    return cs == 0;
-  }
-
-  // Reserved storage space to allow for layout changes in the future.
-  uint256[50] private ______gap;
+    // Reserved storage space to allow for layout changes in the future.
+    uint256[50] private ______gap;
 }

contracts/common/ReentrancyGuard.sol

@@ -1,4 +1,6 @@
-pragma solidity ^0.5.0;
+// SPDX-License-Identifier: UNLICENSED
+pragma solidity ^0.8.9;
+
 import "./Initializable.sol";
 
 /**