Unit testing Connections.ts (#66)

* Jest, Enzyme test env setup

* unit tests for telemetry state update logic

* remove sinon, superfluous scripts

* Remove console log

packages/frontend/package.json

@@ -4,6 +4,20 @@
   "author": "Parity Technologies Ltd. <admin@parity.io>",
   "license": "GPL-3.0",
   "description": "Polkadot Telemetry frontend",
+  "jest": {
+    "moduleFileExtensions": [
+      "ts",
+      "tsx",
+      "js"
+    ],
+    "setupFiles": [
+      "jest-localstorage-mock"
+    ],
+    "transform": {
+      "\\.(ts|tsx)$": "ts-jest"
+    },
+    "testRegex": "/test/.*\\.(spec).(ts|tsx|js)$"
+  },
   "dependencies": {
     "@fnando/sparkline": "maciejhirsz/sparkline",
     "polkadot-identicon": "^1.1.0",
@@ -15,7 +29,7 @@
   "scripts": {
     "start": "react-scripts-ts start",
     "build": "react-scripts-ts build",
-    "test": "react-scripts-ts test --env=jsdom",
+    "test": "jest --coverage",
     "eject": "react-scripts-ts eject"
   },
   "devDependencies": {
@@ -24,6 +38,16 @@
     "@types/react": "^16.3.17",
     "@types/react-dom": "^16.0.6",
     "@types/react-svg": "^3.0.0",
+    "babel-jest": "^23.6.0",
+    "babel-preset-env": "^1.7.0",
+    "babel-preset-react": "^6.24.1",
+    "enzyme": "^3.6.0",
+    "enzyme-adapter-react-16": "^1.5.0",
+    "jest": "^23.6.0",
+    "jest-localstorage-mock": "^2.2.0",
+    "mock-socket": "^8.0.2",
+    "react-test-renderer": "^16.5.2",
+    "ts-jest": "^23.10.2",
     "typescript": "^2.9.2"
   }
 }