chore: add jest

babel.config.js

@@ -0,0 +1,13 @@
+module.exports = {
+    presets: [
+        '@babel/preset-typescript',
+        [
+            '@babel/preset-env',
+            {
+                targets: {
+                    node: 'current',
+                },
+            },
+        ],
+    ],
+};

jest.config.js

@@ -0,0 +1,5 @@
+module.exports = {
+    clearMocks: true,
+    coverageDirectory: "coverage",
+    testEnvironment: "node",
+};

package.json

@@ -9,15 +9,22 @@
     "@actions/core": "^1.2.3",
     "@actions/exec": "^1.0.3",
     "@actions/github": "^2.1.1",
+    "@types/jest": "^26.0.0",
     "got": "^11.3.0",
     "lodash.get": "^4.4.2"
   },
   "devDependencies": {
+    "@babel/core": "^7.10.2",
+    "@babel/preset-env": "^7.10.2",
+    "@babel/preset-typescript": "^7.10.1",
     "@zeit/ncc": "^0.22.0",
+    "babel-jest": "^26.0.1",
+    "jest": "^26.0.1",
     "prettier": "^2.0.2"
   },
   "scripts": {
-    "build": "ncc build main.ts --out dist/main",
+    "build": "ncc build src/main.ts --out dist/main",
-    "watch": "ncc build main.ts --out dist/main --watch"
+    "watch": "ncc build src/main.ts --out dist/main --watch",
+    "test": "jest"
   }
 }