Procedural SafeCast.sol generation (#3245)

scripts/generate/templates/SafeCastMock.js

@@ -0,0 +1,50 @@
+const format = require('../format-lines');
+const { range } = require('../../helpers');
+
+const LENGTHS = range(8, 256, 8).reverse(); // 248 → 8 (in steps of 8)
+
+const header = `\
+pragma solidity ^0.8.0;
+
+import "../utils/math/SafeCast.sol";
+`;
+
+const toInt = length => `\
+function toInt${length}(uint${length} a) public pure returns (int${length}) {
+    return a.toInt${length}();
+}
+`;
+
+const toUint = length => `\
+function toUint${length}(int${length} a) public pure returns (uint${length}) {
+    return a.toUint${length}();
+}
+`;
+
+const toIntDownCast = length => `\
+function toInt${length}(int256 a) public pure returns (int${length}) {
+    return a.toInt${length}();
+}
+`;
+
+const toUintDownCast = length => `\
+function toUint${length}(uint256 a) public pure returns (uint${length}) {
+    return a.toUint${length}();
+}
+`;
+
+// GENERATE
+module.exports = format(
+  header,
+  'contract SafeCastMock {',
+  [
+    'using SafeCast for uint256;',
+    'using SafeCast for int256;',
+    '',
+    toUint(256),
+    ...LENGTHS.map(size => toUintDownCast(size)),
+    toInt(256),
+    ...LENGTHS.map(size => toIntDownCast(size)),
+  ].flatMap(fn => fn.split('\n')).slice(0, -1),
+  '}',
+);