feat: basic code and configurations

jest.config.ts

@@ -0,0 +1,16 @@
+import type { Config } from 'jest';
+
+const config: Config = {
+  preset: 'ts-jest',
+  clearMocks: true,
+  collectCoverage: true,
+  verbose: true,
+  moduleFileExtensions: ['js', 'ts'],
+  collectCoverageFrom: ['src/**/*.ts'],
+  testMatch: ['**/*.test.ts'],
+  transform: {
+    '^.+\\.ts$': '@swc/jest'
+  }
+};
+
+export default config;