Setup jest

Author: inokawa

.github/workflows/check.yml

@@ -27,4 +27,5 @@ jobs:
 
       - run: npm install
       - run: npm run tsc
+      - run: npm run test
       - run: npm run build

jest.config.js

@@ -0,0 +1,5 @@
+module.exports = {
+  transform: {
+    "^.+\\.tsx?$": "ts-jest",
+  },
+};