Install Jest for JavaScript tests

Author: wimpyprogrammer

package.json

@@ -14,7 +14,18 @@
     "format": "prettier --write 'src/**'",
     "lint": "tsc; tslint -p ./",
     "precommit": "pretty-quick --staged",
-    "test": "echo \"Error: no test specified\" && exit 1"
+    "test": "jest"
+  },
+  "jest": {
+    "transform": {
+    },
+    "testMatch": [
+      "**/src/**/?*.spec.js"
+    ],
+    "moduleFileExtensions": [
+      "js",
+      "json"
+    ]
   },
   "dependencies": {},
   "devDependencies": {
@@ -23,6 +34,7 @@
     "@babel/preset-env": "^7.0.0-beta.54",
     "@babel/preset-typescript": "^7.0.0-beta.54",
     "husky": "^0.14.3",
+    "jest": "^23.4.1",
     "prettier": "^1.13.7",
     "pretty-quick": "^1.6.0",
     "rimraf": "^2.6.2",