typescript refactor + testing

Author: James Hrivnak

.gitignore

@@ -1,3 +1,5 @@
 node_modules
 .vscode
-leetCode-api.txt
+leetCode-api.txt
+
+dist

.prettierrc

@@ -0,0 +1,3 @@
+{
+  "singleQuote": true
+}

index.js

@@ -0,0 +1,15 @@
+import type { Config } from '@jest/types';
+
+const customJestConfig: Config.InitialOptions = {
+  preset: 'ts-jest',
+  transform: {
+    '^.+\\.(ts|tsx)?$': 'ts-jest',
+  },
+  moduleDirectories: ['node_modules', '<rootDir>/'],
+  setupFilesAfterEnv: ['<rootDir>/setupTests.ts'],
+  testPathIgnorePatterns: ['<rootDir>/iac'],
+};
+
+module.exports = async function () {
+  return customJestConfig;
+};