added test coverage

.circleci/config.yml

@@ -0,0 +1,28 @@
+version: 2
+jobs:
+  build:
+    docker:                              # CircleCI tags: https://circleci.com/docs/2.0/docker-image-tags.json
+      - image: circleci/node:10-browsers # Node tags: https://nodejs.org/en/download/releases/
+    steps:
+      - checkout
+
+      # Download and cache dependencies
+      - restore_cache:
+          keys:
+            - v1-dependencies-{{ checksum "package.json" }}
+            # fallback to using the latest cache if no exact match is found
+            - v1-dependencies-
+
+      - run: yarn
+
+      - save_cache:
+          paths:
+            - node_modules
+          key: v1-dependencies-{{ checksum "yarn.lock" }}
+
+      - run:
+          name: Lint
+          command: yarn lint
+      - run:
+          name: Test
+          command: yarn test

.eslintrc.js

@@ -0,0 +1,26 @@
+module.exports = {
+  root: true,
+  parserOptions: {
+    ecmaVersion: 2015,
+    sourceType: 'module'
+  },
+  plugins: ['prettier'],
+  extends: ['eslint:recommended', 'plugin:prettier/recommended'],
+  env: {
+    browser: true,
+    node: true
+  },
+  overrides: [
+    {
+      parserOptions: {
+        sourceType: 'module',
+        ecmaVersion: 2017
+      },
+      env: {
+        browser: false,
+        node: true
+      },
+      files: ['test*.js', 'tests/**/*.js']
+    }
+  ]
+};

.gitignore

@@ -1 +1,14 @@
+# See https://help.github.com/ignore-files/ for more about ignoring files.
+
+# dependencies
+/node_modules
+
+# misc
+/.env
+/.tool-versions
+/coverage/*
+/libpeerconnection.log
+npm-debug.log*
 package-lock.json
+yarn-error.log
+

.prettierrc.json

@@ -0,0 +1,3 @@
+{
+  "singleQuote": true
+}

package.json

@@ -6,5 +6,17 @@
   "repository": "git@github.com:0xadada/random-emoji.git",
   "author": "0xADADA <0xadada.pub@0xadada.pub>",
   "license": "MIT",
-  "private": false
+  "private": false,
+  "scripts": {
+    "test": "ava",
+    "lint": "yarn eslint .",
+    "lint:fix": "yarn eslint . --fix"
+  },
+  "devDependencies": {
+    "ava": "^2.4.0",
+    "eslint": "^6.5.1",
+    "eslint-config-prettier": "^6.3.0",
+    "eslint-plugin-prettier": "^3.1.1",
+    "prettier": "^1.18.2"
+  }
 }

random-emoji.js

@@ -5,7 +5,7 @@ const CHAR_RANGE = {
   expressions: [0x1f910, 0x1f92f]
 };
 
-function random(range = "emoticons") {
+function random(range = 'emoticons') {
   let [max, min] = CHAR_RANGE[range];
   let codePoint = Math.floor(Math.random() * (max - min) + min);
   return String.fromCodePoint(codePoint);

test.js

@@ -0,0 +1,37 @@
+import test from 'ava';
+import random from './random-emoji';
+
+test('without arguments it shows an emoticon', t => {
+  const a = random();
+  const cp = a.codePointAt();
+  t.assert(cp >= 0x1f600, 'greater than min');
+  t.assert(cp <= 0x1f64f, 'less than max');
+});
+
+test('with argument "emoticons" it shows an emoticon', t => {
+  const a = random('emoticons');
+  const cp = a.codePointAt();
+  t.assert(cp >= 0x1f600, 'greater than min');
+  t.assert(cp <= 0x1f64f, 'less than max');
+});
+
+test('with argument "food" it shows a food emoji', t => {
+  const a = random('food');
+  const cp = a.codePointAt();
+  t.assert(cp >= 0x1f32d, 'greater than min');
+  t.assert(cp <= 0x1f37f, 'less than max');
+});
+
+test('with argument "animals" it shows an animal friend emoji', t => {
+  const a = random('animals');
+  const cp = a.codePointAt();
+  t.assert(cp >= 0x1f400, 'greater than min');
+  t.assert(cp <= 0x1f4d3, 'less than max');
+});
+
+test('with argument "expressions" it shows an facial expression emoji', t => {
+  const a = random('expressions');
+  const cp = a.codePointAt();
+  t.assert(cp >= 0x1f910, 'greater than min');
+  t.assert(cp <= 0x1f92f, 'less than max');
+});