Add linting and testing configs

jest.config.js

@@ -0,0 +1,37 @@
+// See: https://jestjs.io/docs/configuration
+
+/** @type {import('ts-jest').JestConfigWithTsJest} **/
+export default {
+  clearMocks: true,
+  collectCoverage: true,
+  collectCoverageFrom: ['./src/**'],
+  coverageDirectory: './coverage',
+  coveragePathIgnorePatterns: ['/node_modules/', '/dist/'],
+  coverageReporters: ['json-summary', 'text', 'lcov'],
+  coverageThreshold: {
+    global: {
+      branches: 100,
+      functions: 100,
+      lines: 100,
+      statements: 100
+    }
+  },
+  extensionsToTreatAsEsm: ['.ts'],
+  moduleFileExtensions: ['ts', 'js'],
+  preset: 'ts-jest',
+  reporters: ['default'],
+  resolver: 'ts-jest-resolver',
+  testEnvironment: 'node',
+  testMatch: ['**/*.test.ts'],
+  testPathIgnorePatterns: ['/dist/', '/node_modules/'],
+  transform: {
+    '^.+\\.ts$': [
+      'ts-jest',
+      {
+        tsconfig: 'tsconfig.eslint.json',
+        useESM: true
+      }
+    ]
+  },
+  verbose: true
+}