Test for directories and files with digit prefix (#10667)

* Test for directories and files with digit prefix

* lint

contracts/src/v0.8/vendor/solidity-cborutils/v2.0.0/CBOR.sol

@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: MIT
 pragma solidity ^0.8.4;
 
-import "../../@ensdomains/buffer/0.1.0/Buffer.sol";
+import "../../@ensdomains/buffer/v0.1.0/Buffer.sol";
 
 /**
 * @dev A library for populating CBOR encoded payload in Solidity.

contracts/test/cross-version/directory.test.ts

@@ -0,0 +1,31 @@
+import fs from 'fs'
+import path from 'path'
+import { expect } from 'chai'
+
+// Directories that start with a number do not currently work with typechain (https://github.com/dethcrypto/TypeChain/issues/794)
+describe('Directory', () => {
+  it('Should not have a file or directory starting with a number in contracts/src', () => {
+    const srcPath = path.join(__dirname, '..', '..', 'src')
+
+    const noNumbersAsFirstChar = (dirPath: string): boolean => {
+      const entries = fs.readdirSync(dirPath, { withFileTypes: true })
+
+      for (const entry of entries) {
+        if (/^\d/.test(entry.name)) {
+          throw new Error(
+            `${path.join(dirPath, entry.name)} starts with a number`,
+          )
+        }
+
+        if (entry.isDirectory()) {
+          const newPath = path.join(dirPath, entry.name)
+          noNumbersAsFirstChar(newPath)
+        }
+      }
+
+      return true
+    }
+
+    expect(noNumbersAsFirstChar(srcPath)).to.be.true
+  })
+})