feat: add unit testing and coverage support via jest

.gitignore

@@ -3,7 +3,12 @@
 .DS_Store
 node_modules
 
+coverage
 lib
 lib-esm
 umd
 typings
+
+## this is generated by `npm pack`
+*.tgz
+package

.npmignore

@@ -4,5 +4,11 @@ tsconfig.*.json
 tslint.json
 **/webpack.config.js
 
+__tests__
+coverage
 node_modules
 src
+
+## this is generated by `npm pack`
+*.tgz
+package

package.json

@@ -14,10 +14,12 @@
     "node": ">=6.9"
   },
   "scripts": {
-    "cleanup": "shx rm -rf umd lib lib-esm typings",
+    "cleanup": "shx rm -rf umd lib lib-esm typings coverage",
     "prebuild": "npm run cleanup && npm run verify",
     "build": " tsc && tsc -p tsconfig.es6.json && webpack",
-    "test": "echo \"Error: no test specified\" && exit 0",
+    "test": "jest",
+    "test:watch": "jest --watch",
+    "test:coverage": "jest --coverage",
     "ts:lint": "tslint  --project tsconfig.json --type-check \"src/**/*.tsx\" \"src/**/*.ts\"",
     "ts:lint:fix": "npm run ts:lint -- --fix",
     "ts:format": "tsfmt --verify",
@@ -47,18 +49,56 @@
       "maxSubjectLength": 120
     }
   },
+  "jest": {
+    "globals": {
+      "__TS_CONFIG__": {
+        "module": "commonjs"
+      }
+    },
+    "transform": {
+      ".(ts|tsx)": "<rootDir>/node_modules/ts-jest/preprocessor.js"
+    },
+    "testRegex": "<rootDir>/src/.*(/__tests__/.*|\\.(test|spec))\\.(ts|tsx|js)$",
+    "moduleFileExtensions": [
+      "ts",
+      "tsx",
+      "js"
+    ],
+    "modulePathIgnorePatterns": [
+      "/^((?!src).)/"
+    ],
+    "testResultsProcessor": "<rootDir>/node_modules/ts-jest/coverageprocessor.js",
+    "coveragePathIgnorePatterns": [
+      "<rootDir>/node_modules/",
+      "<rootDir>/lib/",
+      "<rootDir>/lib-esm/",
+      "<rootDir>/umd/",
+      "<rootDir>/src/.*(/__tests__/.*|\\.(test|spec))\\.(ts|tsx|js)$"
+    ],
+    "coverageThreshold": {
+      "global": {
+        "branches": 80,
+        "functions": 80,
+        "lines": 80,
+        "statements": 85
+      }
+    }
+  },
   "dependencies": {},
   "devDependencies": {
+    "@types/jest": "19.2.2",
     "awesome-typescript-loader": "3.0.8",
     "commitizen": "2.9.6",
     "cross-var": "1.0.2",
     "cz-conventional-changelog": "2.0.0",
     "gzip-size-cli": "2.0.0",
     "husky": "0.13.1",
     "irish-pub": "0.2.0",
+    "jest": "19.0.2",
     "shx": "0.2.2",
     "standard-version": "4.0.0",
     "strip-json-comments-cli": "1.0.1",
+    "ts-jest": "19.0.1",
     "tslint": "4.5.1",
     "tslint-react": "2.4.0",
     "typescript": "2.2.1",

src/Greeter.ts

@@ -1,5 +1,5 @@
 export class Greeter {
-  constructor(public greeting: string) { }
+  constructor(private greeting: string) { }
   greet() {
     return `Hello, ${this.greeting}!`;
   }

src/__tests__/Greeter.spec.ts

@@ -0,0 +1,20 @@
+import { Greeter } from '../Greeter';
+
+describe(`Greeter`, () => {
+
+  let greeter: Greeter;
+
+  beforeEach(() => {
+    greeter = new Greeter('World');
+  });
+
+  it(`should greet`, () => {
+
+    const actual = greeter.greet();
+    const expected = 'Hello, World!';
+
+    expect(actual).toBe(expected);
+
+  });
+
+});