Update docs

scripts/generate/templates/Packing.t.js

@@ -0,0 +1,48 @@
+const format = require('../format-lines');
+const { product } = require('../../helpers');
+const { SIZES } = require('./Packing.opts');
+
+// TEMPLATE
+const header = `\
+pragma solidity ^0.8.20;
+
+import {Test} from "forge-std/Test.sol";
+import {Packing} from "@openzeppelin/contracts/utils/Packing.sol";
+`;
+
+const testPack = (left, right) => `\
+function testPack(bytes${left} left, bytes${right} right) external {
+    assertEq(left, Packing.pack_${left}_${right}(left, right).extract_${left + right}_${left}(0));
+    assertEq(right, Packing.pack_${left}_${right}(left, right).extract_${left + right}_${right}(${left}));
+}
+`;
+
+const testReplace = (outer, inner) => `\
+function testReplace(bytes${outer} container, bytes${inner} newValue, uint8 offset) external {
+    offset = uint8(bound(offset, 0, ${outer - inner}));
+
+    bytes${inner} oldValue = container.extract_${outer}_${inner}(offset);
+
+    assertEq(newValue, container.replace_${outer}_${inner}(newValue, offset).extract_${outer}_${inner}(offset));
+    assertEq(container, container.replace_${outer}_${inner}(newValue, offset).replace_${outer}_${inner}(oldValue, offset));
+}
+`;
+
+// GENERATE
+module.exports = format(
+  header,
+  'contract PackingTest is Test {',
+  format(
+    [].concat(
+      'using Packing for *;',
+      '',
+      product(SIZES, SIZES)
+        .filter(([left, right]) => SIZES.includes(left + right))
+        .map(([left, right]) => testPack(left, right)),
+      product(SIZES, SIZES)
+        .filter(([outer, inner]) => outer > inner)
+        .map(([outer, inner]) => testReplace(outer, inner)),
+    ),
+  ).trimEnd(),
+  '}',
+);