feat: port to typescript

* Wrapper was showing it's age, dated syntax, zero tests, et cetera.
* Ported wrapper to Typescript.
* Actually, was a full rewrite, the original interfacing was too obscure.
* Added linting (Airbnb).
* Rewrite includes full feature parity with the Holiday API service.
* This includes support for additional endpoints and latest request parameters.
* Added a ton of additional examples to the README.
* Finally got testing into the mix.
* Added Travis for CI and Coveralls for coverage reporting.

.eslintrc.json

@@ -0,0 +1,31 @@
+{
+    "env": {
+        "browser": true,
+        "es6": true,
+        "jest/globals": true,
+        "node": true
+    },
+    "extends": [
+        "airbnb-base",
+        "plugin:import/typescript"
+    ],
+    "globals": {
+        "Atomics": "readonly",
+        "SharedArrayBuffer": "readonly"
+    },
+    "parser": "@typescript-eslint/parser",
+    "parserOptions": {
+        "ecmaVersion": 2018,
+        "sourceType": "module"
+    },
+    "plugins": [
+      "@typescript-eslint",
+      "jest"
+    ],
+    "rules": {
+      "@typescript-eslint/no-unused-vars": "error",
+      "import/prefer-default-export": "off",
+      "lines-between-class-members": "off",
+      "no-unused-vars": "off"
+    }
+}

.gitignore

@@ -1,37 +1,2 @@
-# Logs
-logs
-*.log
-npm-debug.log*
-
-# Runtime data
-pids
-*.pid
-*.seed
-
-# Directory for instrumented libs generated by jscoverage/JSCover
-lib-cov
-
-# Coverage directory used by tools like istanbul
-coverage
-
-# nyc test coverage
-.nyc_output
-
-# Grunt intermediate storage (http://gruntjs.com/creating-plugins#storing-task-files)
-.grunt
-
-# node-waf configuration
-.lock-wscript
-
-# Compiled binary addons (http://nodejs.org/api/addons.html)
-build/Release
-
-# Dependency directories
 node_modules
-jspm_packages
-
-# Optional npm cache directory
-.npm
-
-# Optional REPL history
-.node_repl_history
+npm-debug.log*

.npmignore

@@ -0,0 +1,2 @@
+tsconfig.json
+src

.travis.yml

@@ -0,0 +1,8 @@
+language: node_js
+node_js:
+  - 7
+  - 8
+  - 9
+  - 10
+  - 11
+  - 12

LICENSE

@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2016 Josh Sherman
+Copyright (c) 2016, 2017, 2018, 2019 Gravity Boulevard, LLC
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

README.md

@@ -1,33 +1,176 @@
 # node-holidayapi
+
 Official Node.js library for [Holiday API](https://holidayapi.com)
 
+[![License](https://img.shields.io/npm/l/node-holidayapi?style=for-the-badge)](https://github.com/holidayapi/node-holidayapi/blob/master/LICENSE)
+![Node Version](https://img.shields.io/node/v/node-holidayapi?style=for-the-badge)
+![Build Status](https://img.shields.io/travis/holidayapi/node-holidayapi/master?style=for-the-badge)
+[![Coverage Status](https://img.shields.io/coveralls/github/holidayapi/node-holidayapi/master?style=for-the-badge)](https://coveralls.io/github/holidayapi/node-holidayapi?branch=master)
+
 ## Installation
 
 ```shell
+# NPM
 npm install --save node-holidayapi
+
+# Yarn
+yarn add node-holidayapi
 ```
 
 ## Usage
 
 ```javascript
-var HolidayAPI = require('node-holidayapi');
-var hapi = new HolidayAPI('_YOUR_API_KEY_').v1;
+import { HolidayAPI } from 'node-holidayapi';
 
-var parameters = {
-  // Required
+const key = 'Insert your API key here';
+const holidayApi = new HolidayAPI({ key });
+
+// Fetch supported countries and subdivisions
+holidayApi.countries()
+  .then((countries) => { console.log(countries); })
+  .catch((err) => { console.error(err); });
+
+// Fetch supported languages
+holidayApi.languages();
+  .then((languages) => { console.log(languages); })
+  .catch((err) => { console.error(err); });
+
+// Fetch holidays with minimum parameters
+holidayApi.holidays({ country: 'US', year: 2019 });
+  .then((holidays) => { console.log(holidays); })
+  .catch((err) => { console.error(err); });
+
+// Async? Await? No problem!
+(async () => {
+  // Fetch supported countries and subdivisions
+  const countries = await holidayApi.countries();
+
+  // Fetch supported languages
+  const languages = await holidayApi.languages();
+
+  // Fetch holidays with minimum parameters
+  const holidays = await holidayApi.holidays({
+    country: 'US',
+    year: 2019,
+  });
+})();
+```
+
+## Examples
+
+### Fetch holidays for a specific year
+
+```javascript
+holidayApi.holidays({
   country: 'US',
-  year:    2016,
-  // Optional
-  // month:    7,
-  // day:      4,
-  // previous: true,
-  // upcoming: true,
-  // public:   true,
-  // pretty:   true,
-};
-
-hapi.holidays(parameters, function (err, data) {
-  // Insert awesome code here...
+  year: 2019,
 });
 ```
 
+### Fetch holidays for a specific month
+
+```javascript
+holidayApi.holidays({
+  country: 'US',
+  year: 2019,
+  month: 7,
+});
+```
+
+### Fetch holidays for a specific day
+
+```javascript
+holidayApi.holidays({
+  country: 'US',
+  year: 2019,
+  month: 7,
+  day: 4,
+});
+```
+
+### Fetch upcoming holidays based on a specific date
+
+```javascript
+holidayApi.holidays({
+  country: 'US',
+  year: 2019,
+  month: 7,
+  day: 4,
+  upcoming: true,
+});
+```
+
+### Fetch previous holidays based on a specific date
+
+```javascript
+holidayApi.holidays({
+  country: 'US',
+  year: 2019,
+  month: 7,
+  day: 4,
+  previous: true,
+});
+```
+
+### Fetch only public holidays
+
+```javascript
+holidayApi.holidays({
+  country: 'US',
+  year: 2019,
+  public: true,
+});
+```
+
+### Fetch holidays for a specific subdivision
+
+```javascript
+holidayApi.holidays({
+  country: 'GB-ENG',
+  year: 2019,
+});
+```
+
+### Include subdivision holidays with countrywide holidays
+
+```javascript
+holidayApi.holidays({
+  country: 'US',
+  year: 2019,
+  subdivisions: true,
+});
+```
+
+### Search for a holiday by name
+
+```javascript
+holidayApi.holidays({
+  country: 'US',
+  year: 2019,
+  search: 'New Year',
+});
+```
+
+### Translate holidays to another language
+
+```javascript
+holidayApi.holidays({
+  country: 'US',
+  year: 2019,
+  language: 'zh', // Chinese (Simplified)
+});
+```
+
+### Fetch holidays for multiple countries
+
+```javascript
+holidayApi.holidays({
+  country: 'US,GB,NZ',
+  year: 2019,
+});
+
+holidayApi.holidays({
+  country: ['US', 'GB', 'NZ'],
+  year: 2019,
+});
+```

dist/holidayapi.d.ts

@@ -0,0 +1,14 @@
+import { CountriesResponse, HolidaysResponse, HolidaysRequest, LanguagesResponse, Request } from './types';
+export declare class HolidayAPI {
+    baseUrl: string;
+    key: string;
+    constructor({ key, version }: {
+        key?: string;
+        version?: number;
+    });
+    private createUrl;
+    private request;
+    countries(request?: Request): Promise<CountriesResponse>;
+    holidays(request?: HolidaysRequest): Promise<HolidaysResponse>;
+    languages(request?: Request): Promise<LanguagesResponse>;
+}

dist/holidayapi.js

@@ -0,0 +1,136 @@
+"use strict";
+var __assign = (this && this.__assign) || function () {
+    __assign = Object.assign || function(t) {
+        for (var s, i = 1, n = arguments.length; i < n; i++) {
+            s = arguments[i];
+            for (var p in s) if (Object.prototype.hasOwnProperty.call(s, p))
+                t[p] = s[p];
+        }
+        return t;
+    };
+    return __assign.apply(this, arguments);
+};
+var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
+    return new (P || (P = Promise))(function (resolve, reject) {
+        function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
+        function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
+        step((generator = generator.apply(thisArg, _arguments || [])).next());
+    });
+};
+var __generator = (this && this.__generator) || function (thisArg, body) {
+    var _ = { label: 0, sent: function() { if (t[0] & 1) throw t[1]; return t[1]; }, trys: [], ops: [] }, f, y, t, g;
+    return g = { next: verb(0), "throw": verb(1), "return": verb(2) }, typeof Symbol === "function" && (g[Symbol.iterator] = function() { return this; }), g;
+    function verb(n) { return function (v) { return step([n, v]); }; }
+    function step(op) {
+        if (f) throw new TypeError("Generator is already executing.");
+        while (_) try {
+            if (f = 1, y && (t = op[0] & 2 ? y["return"] : op[0] ? y["throw"] || ((t = y["return"]) && t.call(y), 0) : y.next) && !(t = t.call(y, op[1])).done) return t;
+            if (y = 0, t) op = [op[0] & 2, t.value];
+            switch (op[0]) {
+                case 0: case 1: t = op; break;
+                case 4: _.label++; return { value: op[1], done: false };
+                case 5: _.label++; y = op[1]; op = [0]; continue;
+                case 7: op = _.ops.pop(); _.trys.pop(); continue;
+                default:
+                    if (!(t = _.trys, t = t.length > 0 && t[t.length - 1]) && (op[0] === 6 || op[0] === 2)) { _ = 0; continue; }
+                    if (op[0] === 3 && (!t || (op[1] > t[0] && op[1] < t[3]))) { _.label = op[1]; break; }
+                    if (op[0] === 6 && _.label < t[1]) { _.label = t[1]; t = op; break; }
+                    if (t && _.label < t[2]) { _.label = t[2]; _.ops.push(op); break; }
+                    if (t[2]) _.ops.pop();
+                    _.trys.pop(); continue;
+            }
+            op = body.call(thisArg, _);
+        } catch (e) { op = [6, e]; y = 0; } finally { f = t = 0; }
+        if (op[0] & 5) throw op[1]; return { value: op[0] ? op[1] : void 0, done: true };
+    }
+};
+Object.defineProperty(exports, "__esModule", { value: true });
+var node_fetch_1 = require("node-fetch");
+var url_1 = require("url");
+var HolidayAPI = (function () {
+    function HolidayAPI(_a) {
+        var key = _a.key, _b = _a.version, version = _b === void 0 ? 1 : _b;
+        var getYours = 'get yours at HolidayAPI.com';
+        var uuidRegExp = /[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}/;
+        if (!key) {
+            throw new Error("Missing API key, " + getYours);
+        }
+        if (!uuidRegExp.test(key)) {
+            throw new Error("Invalid API key, " + getYours);
+        }
+        if (version !== 1) {
+            throw new Error('Invalid version number, expected "1"');
+        }
+        this.baseUrl = "https://holidayapi.com/v" + version + "/";
+        this.key = key;
+    }
+    HolidayAPI.prototype.createUrl = function (endpoint, request) {
+        var parameters = __assign({ key: this.key }, request);
+        var url = new url_1.URL(endpoint, this.baseUrl);
+        url.search = new url_1.URLSearchParams(parameters).toString();
+        return url.toString();
+    };
+    HolidayAPI.prototype.request = function (endpoint, request) {
+        return __awaiter(this, void 0, void 0, function () {
+            var response, payload, err_1;
+            return __generator(this, function (_a) {
+                switch (_a.label) {
+                    case 0: return [4, node_fetch_1.default(this.createUrl(endpoint, request))];
+                    case 1:
+                        response = _a.sent();
+                        _a.label = 2;
+                    case 2:
+                        _a.trys.push([2, 4, , 5]);
+                        return [4, response.json()];
+                    case 3:
+                        payload = _a.sent();
+                        return [3, 5];
+                    case 4:
+                        err_1 = _a.sent();
+                        payload = {};
+                        return [3, 5];
+                    case 5:
+                        if (!response.ok) {
+                            throw new Error(payload.error || response.statusText);
+                        }
+                        return [2, payload];
+                }
+            });
+        });
+    };
+    HolidayAPI.prototype.countries = function (request) {
+        return __awaiter(this, void 0, void 0, function () {
+            return __generator(this, function (_a) {
+                return [2, this.request('countries', request)];
+            });
+        });
+    };
+    HolidayAPI.prototype.holidays = function (request) {
+        if (request === void 0) { request = {}; }
+        return __awaiter(this, void 0, void 0, function () {
+            return __generator(this, function (_a) {
+                if (!request.country) {
+                    throw new Error('Missing country');
+                }
+                else if (!request.year) {
+                    throw new Error('Missing year');
+                }
+                else if (request.previous && request.upcoming) {
+                    throw new Error('Previous and upcoming are mutually exclusive');
+                }
+                return [2, this.request('holidays', request)];
+            });
+        });
+    };
+    HolidayAPI.prototype.languages = function (request) {
+        return __awaiter(this, void 0, void 0, function () {
+            return __generator(this, function (_a) {
+                return [2, this.request('languages', request)];
+            });
+        });
+    };
+    return HolidayAPI;
+}());
+exports.HolidayAPI = HolidayAPI;

dist/index.d.ts

@@ -0,0 +1,2 @@
+export * from './types';
+export * from './holidayapi';

dist/index.js

@@ -0,0 +1,6 @@
+"use strict";
+function __export(m) {
+    for (var p in m) if (!exports.hasOwnProperty(p)) exports[p] = m[p];
+}
+Object.defineProperty(exports, "__esModule", { value: true });
+__export(require("./holidayapi"));

dist/types.d.ts

@@ -0,0 +1,64 @@
+export declare type Endpoint = 'countries' | 'holidays' | 'languages';
+export declare type Request = {
+    key?: string;
+    format?: 'csv' | 'json' | 'php' | 'tsv' | 'yaml' | 'xml';
+    pretty?: boolean;
+};
+export declare type Requests = Request | HolidaysRequest;
+export declare type HolidaysRequest = Request & {
+    country?: string;
+    year?: number;
+    day?: number;
+    month?: number;
+    language?: string;
+    previous?: boolean;
+    public?: boolean;
+    search?: string;
+    subdivisions?: boolean;
+    upcoming?: boolean;
+};
+export declare type Response = {
+    requests: {
+        available: number;
+        resets: Date;
+        used: number;
+    };
+    status: number;
+    error?: string;
+};
+export declare type Responses = (CountriesResponse | HolidaysResponse | LanguagesResponse);
+export declare type CountriesResponse = Response & {
+    countries?: {
+        code: string;
+        codes: {
+            'alpha-2': string;
+            'alpha-3': string;
+            numeric: string;
+        };
+        flag: string;
+        languages: string[];
+        name: string;
+        subdivisions: {
+            code: string;
+            languages: string[];
+            name: string;
+        }[];
+    }[];
+};
+export declare type HolidaysResponse = Response & {
+    holidays?: {
+        country: string;
+        date: Date;
+        name: string;
+        observed: Date;
+        public: boolean;
+        uuid: string;
+        subdivisions?: string[];
+    }[];
+};
+export declare type LanguagesResponse = Response & {
+    languages?: {
+        code: string;
+        name: string;
+    }[];
+};

dist/types.js

@@ -0,0 +1,2 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });

index.js

@@ -1,49 +0,0 @@
-'use strict';
-
-const https = require('https');
-const qs = require('querystring');
-
-var HolidayAPI = function (key) {
-  if ('undefined' !== typeof key) {
-    HolidayAPI.prototype.key = key;
-  }
-};
-
-HolidayAPI.prototype.v1 = {};
-
-HolidayAPI.prototype.v1.holidays = function (parameters, callback) {
-  const querystringObject = Object.assign(
-    {},
-    {key: HolidayAPI.prototype.key},
-    parameters,
-  )
-  const querystring = qs.stringify(querystringObject);
-  const url = `https://holidayapi.com/v1/holidays?${querystring}`;
-
-  https.get(url, function (res) {
-    res.on('data', function (data) {
-      try {
-        data = JSON.parse(data);
-      } catch (e) {
-        data = {};
-      }
-
-      var error = null;
-
-      if (res.statusCode !== 200) {
-        if ('undefined' === typeof data['error']) {
-          error = 'Unknown error.';
-        } else {
-          error = data.error;
-        }
-      }
-
-      return callback(error, data);
-    });
-  }).on('error', function (e) {
-    callback(e.message);
-  });
-};
-
-module.exports = HolidayAPI;
-

jest.config.js

@@ -0,0 +1,4 @@
+module.exports = {
+  preset: 'ts-jest',
+  testEnvironment: 'node',
+};

package.json

@@ -1,20 +1,49 @@
 {
   "name": "node-holidayapi",
-  "version": "1.0.2",
+  "version": "2.0.0",
   "description": "Official Node.js library for Holiday API",
-  "main": "index.js",
-  "scripts": {
-    "test": "echo \"Error: no test specified\" && exit 1"
-  },
+  "main": "dist/index.js",
+  "types": "dist/index.d.ts",
   "repository": {
     "type": "git",
-    "url": "git+https://github.com/joshtronic/node-holidayapi.git"
+    "url": "git+https://github.com/holidayapi/node-holidayapi.git"
   },
-  "keywords": [ "holiday", "holidays", "holidayapi" ],
+  "keywords": [
+    "calendar",
+    "holiday",
+    "holidays",
+    "holidayapi"
+  ],
   "author": "Josh Sherman <hello@holidayapi.com> (https://holidayapi.com)",
   "license": "MIT",
   "bugs": {
-    "url": "https://github.com/joshtronic/node-holidayapi/issues"
+    "url": "https://github.com/holidayapi/node-holidayapi/issues"
   },
-  "homepage": "https://holidayapi.com"
+  "homepage": "https://holidayapi.com",
+  "engines": {
+    "node": ">= 7.0.0"
+  },
+  "devDependencies": {
+    "@types/jest": "^24.0.18",
+    "@types/nock": "^10.0.3",
+    "@types/node": "^12.7.4",
+    "@types/node-fetch": "^2.5.0",
+    "@typescript-eslint/eslint-plugin": "^2.2.0",
+    "@typescript-eslint/parser": "^2.2.0",
+    "coveralls": "^3.0.6",
+    "eslint": "^6.3.0",
+    "eslint-config-airbnb-base": "^14.0.0",
+    "eslint-plugin-import": "^2.18.2",
+    "eslint-plugin-jest": "^22.17.0",
+    "jest": "^24.9.0",
+    "nock": "^10.0.6",
+    "ts-jest": "^24.0.2",
+    "typescript": "^3.6.2"
+  },
+  "dependencies": {
+    "node-fetch": "^2.6.0"
+  },
+  "scripts": {
+    "test": "jest --coverage --coverageReporters=text-lcov | coveralls"
+  }
 }

src/holidayapi.ts

@@ -0,0 +1,83 @@
+/**
+ * Copyright (c) Gravity Boulevard, LLC
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import fetch from 'node-fetch';
+import { URL, URLSearchParams } from 'url';
+import {
+  CountriesResponse, Endpoint, HolidaysResponse, HolidaysRequest,
+  LanguagesResponse, Request, Requests, Responses,
+} from './types';
+
+export class HolidayAPI {
+  baseUrl: string;
+  key: string;
+
+  constructor({ key, version = 1 }: { key?: string, version?: number }) {
+    const getYours = 'get yours at HolidayAPI.com';
+    const uuidRegExp = /[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}/;
+
+    if (!key) {
+      throw new Error(`Missing API key, ${getYours}`);
+    }
+
+    if (!uuidRegExp.test(key)) {
+      throw new Error(`Invalid API key, ${getYours}`);
+    }
+
+
+    if (version !== 1) {
+      throw new Error('Invalid version number, expected "1"');
+    }
+
+    this.baseUrl = `https://holidayapi.com/v${version}/`;
+    this.key = key;
+  }
+
+  private createUrl(endpoint: Endpoint, request?: Requests): string {
+    const parameters = { key: this.key, ...request } as any;
+    const url = new URL(endpoint, this.baseUrl);
+    url.search = new URLSearchParams(parameters).toString();
+    return url.toString();
+  }
+
+  private async request(endpoint: Endpoint, request?: Requests): Promise<Responses> {
+    const response = await fetch(this.createUrl(endpoint, request));
+    let payload;
+
+    try {
+      payload = await response.json();
+    } catch (err) {
+      payload = {};
+    }
+
+    if (!response.ok) {
+      throw new Error(payload.error || response.statusText);
+    }
+
+    return payload;
+  }
+
+  async countries(request?: Request): Promise<CountriesResponse> {
+    return this.request('countries', request);
+  }
+
+  async holidays(request: HolidaysRequest = {}): Promise<HolidaysResponse> {
+    if (!request.country) {
+      throw new Error('Missing country');
+    } else if (!request.year) {
+      throw new Error('Missing year');
+    } else if (request.previous && request.upcoming) {
+      throw new Error('Previous and upcoming are mutually exclusive');
+    }
+
+    return this.request('holidays', request);
+  }
+
+  async languages(request?: Request): Promise<LanguagesResponse> {
+    return this.request('languages', request);
+  }
+}

src/index.ts

@@ -0,0 +1,9 @@
+/**
+ * Copyright (c) Gravity Boulevard, LLC
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+export * from './types';
+export * from './holidayapi';

src/types.ts

@@ -0,0 +1,81 @@
+/**
+ * Copyright (c) Gravity Boulevard, LLC
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+export type Endpoint = 'countries' | 'holidays' | 'languages';
+
+export type Request = {
+  key?: string,
+  format?: 'csv' | 'json' | 'php' | 'tsv' | 'yaml' | 'xml',
+  pretty?: boolean,
+};
+
+export type Requests = Request | HolidaysRequest;
+
+export type HolidaysRequest = Request & {
+  country?: string,
+  year?: number,
+  day?: number,
+  month?: number,
+  language?: string,
+  previous?: boolean,
+  public?: boolean,
+  search?: string,
+  subdivisions?: boolean,
+  upcoming?: boolean,
+};
+
+export type Response = {
+  requests: {
+    available: number,
+    resets: Date,
+    used: number,
+  },
+  status: number,
+  error?: string,
+};
+
+export type Responses = (
+  CountriesResponse | HolidaysResponse | LanguagesResponse
+);
+
+export type CountriesResponse = Response & {
+  countries?: {
+    code: string,
+    codes: {
+      'alpha-2': string,
+      'alpha-3': string,
+      numeric: string,
+    },
+    flag: string,
+    languages: string[],
+    name: string,
+    subdivisions: {
+      code: string,
+      languages: string[],
+      name: string,
+    }[],
+  }[],
+};
+
+export type HolidaysResponse = Response & {
+  holidays?: {
+    country: string,
+    date: Date,
+    name: string,
+    observed: Date,
+    public: boolean,
+    uuid: string,
+    subdivisions?: string[],
+  }[],
+};
+
+export type LanguagesResponse = Response & {
+  languages?: {
+    code: string,
+    name: string,
+  }[],
+};

tests/holidayapi.test.ts

@@ -0,0 +1,299 @@
+import * as nock from 'nock';
+import { HolidayAPI } from '../src/holidayapi';
+
+const baseUrl = 'https://holidayapi.com/v1/';
+const key = 'b58e6dec-8a47-459f-a3c1-eaa26eb4dd30';
+
+describe('holidayapi', () => {
+  describe('instantiation', () => {
+    it('should error when key is missing', () => {
+      expect.assertions(1);
+      expect(() => {
+        const holidayapi = new HolidayAPI({});
+        expect(holidayapi.key).toBeUndefined();
+      }).toThrowError(/missing api key/i);
+    });
+
+    it('should error when key is invalid format', () => {
+      expect.assertions(1);
+      expect(() => {
+        const holidayapi = new HolidayAPI({
+          key: 'zzzzzzzz-zzzz-zzzz-zzzz-zzzzzzzzzzzz',
+        });
+        expect(holidayapi.key).toBeUndefined();
+      }).toThrowError(/invalid api key/i);
+    });
+
+    it('should error when version is too low', () => {
+      expect.assertions(1);
+      expect(() => {
+        const holidayapi = new HolidayAPI({ key, version: 0 });
+        expect(holidayapi.baseUrl).toBeUndefined();
+      }).toThrowError(/invalid version/i);
+    });
+
+    it('should error when version is too high', () => {
+      expect.assertions(1);
+      expect(() => {
+        const holidayapi = new HolidayAPI({ key, version: 2 });
+        expect(holidayapi.baseUrl).toBeUndefined();
+      }).toThrowError(/invalid version/i);
+    });
+
+    it('should assign class members', () => {
+      const holidayapi = new HolidayAPI({ key });
+      expect(holidayapi.baseUrl).toBe(baseUrl);
+      expect(holidayapi.key).toBe(key);
+    });
+  });
+
+  describe('v1 requests', () => {
+    const holidayapi = new HolidayAPI({ key });
+    const mockRequest = nock(baseUrl);
+
+    describe('/v1/countries', () => {
+      const basePath = `/countries?key=${key}`;
+
+      it('should return countries', async () => {
+        const expectedResponse = {
+          status: 200,
+          requests: {
+            used: 1000,
+            available: 9000,
+            resets: '2019-10-01 00:00:00',
+          },
+          countries: [
+            {
+              code: 'ST',
+              name: 'Sao Tome and Principe',
+              languages: ['pt'],
+              codes: {
+                'alpha-2': 'ST',
+                'alpha-3': 'STP',
+                numeric: 678,
+              },
+              flag: 'https://www.countryflags.io/ST/flat/64.png',
+              subdivisions: [
+                {
+                  code: 'ST-P',
+                  name: 'Príncipe',
+                  languages: ['pt'],
+                },
+                {
+                  code: 'ST-S',
+                  name: 'São Tomé',
+                  languages: ['pt'],
+                },
+              ],
+            },
+          ],
+        };
+
+        mockRequest.get(basePath).reply(200, expectedResponse);
+        expect(await holidayapi.countries()).toStrictEqual(expectedResponse);
+      });
+
+      it('should raise 4xx errors', async () => {
+        const expectedResponse = {
+          status: 429,
+          error: 'Rate limit exceeded',
+        };
+
+        expect.assertions(1);
+        mockRequest.get(basePath).reply(429, expectedResponse);
+
+        try {
+          await holidayapi.countries();
+        } catch (err) {
+          expect(err.message).toMatch(/rate limit exceeded/i);
+        }
+      });
+
+      it('should raise 5xx errors', async () => {
+        expect.assertions(1);
+        mockRequest.get(basePath).reply(500);
+
+        try {
+          await holidayapi.countries();
+        } catch (err) {
+          expect(err.message).toMatch(/internal server error/i);
+        }
+      });
+    });
+
+    describe('/v1/holidays', () => {
+      const basePath = `/holidays?key=${key}`;
+
+      it('should return holidays', async () => {
+        const expectedResponse = {
+          status: 200,
+          requests: {
+            used: 1000,
+            available: 9000,
+            resets: '2019-10-01 00:00:00',
+          },
+          holidays: [
+            {
+              name: 'Independence Day',
+              date: '2015-07-04',
+              observed: '2015-07-03',
+              public: true,
+              country: 'US',
+              uuid: '88268759-9b90-468c-804f-b729b8418e7c',
+              weekday: {
+                date: {
+                  name: 'Saturday',
+                  numeric: '6',
+                },
+                observed: {
+                  name: 'Friday',
+                  numeric: '5',
+                },
+              },
+            },
+          ],
+        };
+
+        mockRequest.get(`${basePath}&country=US&year=2019&month=7&day=4`)
+          .reply(200, expectedResponse);
+
+        expect(await holidayapi.holidays({
+          country: 'US',
+          year: 2019,
+          month: 7,
+          day: 4,
+        })).toStrictEqual(expectedResponse);
+      });
+
+      it('should error when country is missing', async () => {
+        expect.assertions(1);
+
+        try {
+          await holidayapi.holidays();
+        } catch (err) {
+          expect(err.message).toMatch(/missing country/i);
+        }
+      });
+
+      it('should error when year is missing', async () => {
+        expect.assertions(1);
+
+        try {
+          await holidayapi.holidays({ country: 'US' });
+        } catch (err) {
+          expect(err.message).toMatch(/missing year/i);
+        }
+      });
+
+      it('should error when both previous and upcoming', async () => {
+        expect.assertions(1);
+
+        try {
+          await holidayapi.holidays({
+            country: 'US',
+            year: 2019,
+            previous: true,
+            upcoming: true,
+          });
+        } catch (err) {
+          expect(err.message).toMatch(/previous and upcoming/i);
+        }
+      });
+
+      it('should raise 4xx errors', async () => {
+        const expectedResponse = {
+          status: 429,
+          error: 'Rate limit exceeded',
+        };
+
+        expect.assertions(1);
+        mockRequest.get(`${basePath}&country=US&year=2019`)
+          .reply(429, expectedResponse);
+
+        try {
+          await holidayapi.holidays({ country: 'US', year: 2019 });
+        } catch (err) {
+          expect(err.message).toMatch(/rate limit exceeded/i);
+        }
+      });
+
+      it('should raise 5xx errors', async () => {
+        expect.assertions(1);
+        mockRequest.get(`${basePath}&country=US&year=2019`).reply(500);
+
+        try {
+          await holidayapi.holidays({ country: 'US', year: 2019 });
+        } catch (err) {
+          expect(err.message).toMatch(/internal server error/i);
+        }
+      });
+    });
+
+    describe('/v1/languages', () => {
+      const basePath = `/languages?key=${key}`;
+
+      it('should return languages', async () => {
+        const expectedResponse = {
+          status: 200,
+          requests: {
+            used: 1000,
+            available: 9000,
+            resets: '2019-10-01 00:00:00',
+          },
+          languages: [
+            {
+              code: 'ar',
+              name: 'Arabic',
+            },
+            {
+              code: 'en',
+              name: 'English',
+            },
+            {
+              code: 'es',
+              name: 'Spanish, Castilian',
+            },
+            {
+              code: 'hi',
+              name: 'Hindi',
+            },
+            {
+              code: 'zh',
+              name: 'Chinese (Simplified)',
+            },
+          ],
+        };
+
+        mockRequest.get(basePath).reply(200, expectedResponse);
+        expect(await holidayapi.languages()).toStrictEqual(expectedResponse);
+      });
+
+      it('should raise 4xx errors', async () => {
+        const expectedResponse = {
+          status: 429,
+          error: 'Rate limit exceeded',
+        };
+
+        expect.assertions(1);
+        mockRequest.get(basePath).reply(429, expectedResponse);
+
+        try {
+          await holidayapi.languages();
+        } catch (err) {
+          expect(err.message).toMatch(/rate limit exceeded/i);
+        }
+      });
+
+      it('should raise 5xx errors', async () => {
+        expect.assertions(1);
+        mockRequest.get(basePath).times(2).reply(500);
+
+        try {
+          await holidayapi.languages();
+        } catch (err) {
+          expect(err.message).toMatch(/internal server error/i);
+        }
+      });
+    });
+  });
+});

tsconfig.json

@@ -0,0 +1,15 @@
+{
+  "compilerOptions": {
+    "target": "es5",
+    "module": "commonjs",
+    "declaration": true,
+    "outDir": "./dist",
+    "strict": true,
+    "removeComments": true,
+    "noUnusedLocals": true,
+    "noUnusedParameters": true
+  },
+  "include": [
+    "src/**/*"
+  ]
+}