Initial commit.

javascript-practice/src/rSpreadOperator/spreadOperator.js

+export class Accumulator {
+  constructor() {
+    this.content = [];
+  }
+
+  addAll(content) {
+    // INSTRUCTIONS: Change the arguments to the `push` method so that all of
+    // the elements in `content` are added as elements to `this.content`.
+    //
+    // Resources:
+    // <https://javascript.info/array#methods-pop-push-shift-unshift>
+    // <https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/push>
+    // <https://javascript.info/rest-parameters-spread#spread-syntax>
+    // <https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Spread_syntax>
+    this.content.push();
+  }
+}

javascript-practice/src/rSpreadOperator/spreadOperator.key.js

+export class Accumulator {
+  constructor() {
+    this.content = [];
+  }
+
+  addAll(content) {
+    this.content.push(...content);
+  }
+}

javascript-practice/src/rSpreadOperator/spreadOperator.test.js

+import { Accumulator } from './spreadOperator.js';
+
+describe('the `Accumulator` class', () => {
+  test('starts out empty', () => {
+    const accumulator = new Accumulator();
+    expect(accumulator.content).toEqual([]);
+  });
+  test('can accumulate one element at a time', () => {
+    const accumulator = new Accumulator();
+    accumulator.addAll(['foo']);
+    accumulator.addAll(['bar']);
+    expect(accumulator.content).toEqual(['foo', 'bar']);
+  });
+  test('can accumulate several elements at once', () => {
+    const accumulator = new Accumulator();
+    accumulator.addAll(['foo', 'bar', 'baz']);
+    expect(accumulator.content).toEqual(['foo', 'bar', 'baz']);
+  });
+});

javascript-practice/src/sArrowFunctions/arrowFunctions.js

+export function makeBetweenFilter(low, high) {
+  // INSTRUCTIONS: Return an arrow function that checks whether a number is
+  // between low (inclusive) and high (exclusive).
+  //
+  // Resources:
+  // <https://javascript.info/arrow-functions-basics>
+  // <https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/Arrow_functions>
+  // <https://developer.mozilla.org/en-US/docs/Web/JavaScript/Closures>
+  // <https://javascript.info/closure#lexical-environment>
+}

javascript-practice/src/sArrowFunctions/arrowFunctions.key.js

+export function makeBetweenFilter(low, high) {
+  return (number) => low <= number && number < high;
+}

javascript-practice/src/sArrowFunctions/arrowFunctions.test.js

+import { makeBetweenFilter } from './arrowFunctions.js';
+
+describe('the `makeBetweenFilter` function', () => {
+  test('makes a filter that rejects numbers that are below the lower bound', () => {
+    const filter = makeBetweenFilter(0, 10);
+    expect(filter(-1)).toBe(false);
+  });
+  test('makes a filter that accepts numbers that are the lower bound', () => {
+    const filter = makeBetweenFilter(0, 10);
+    expect(filter(0)).toBe(true);
+  });
+  test('makes a filter that accepts numbers that are between the bounds', () => {
+    const filter = makeBetweenFilter(0, 10);
+    expect(filter(1)).toBe(true);
+    expect(filter(9)).toBe(true);
+  });
+  test('makes a filter that rejects numbers that are the upper bound', () => {
+    const filter = makeBetweenFilter(0, 10);
+    expect(filter(10)).toBe(false);
+  });
+  test('makes a filter that rejects numbers that are above the upper bound', () => {
+    const filter = makeBetweenFilter(0, 10);
+    expect(filter(11)).toBe(false);
+  });
+});

package.json

+{
+  "name": "@unlsoft/javascript-practice",
+  "version": "1.0.0",
+  "description": "A collection of small JavaScript exercises for practice when learning the language.",
+  "private": true,
+  "license": "UNLICENSED",
+  "scripts": {
+    "postinstall:eslint-config": "cd eslint-config && npm install",
+    "postinstall:app": "cd javascript-practice && npm install",
+    "postinstall": "run-s postinstall:**",
+    "lint:app": "cd javascript-practice && npm run lint",
+    "lint": "run-s --continue-on-error lint:**",
+    "test-once:a": "cd javascript-practice && npm run test-once:a",
+    "test-once:b": "cd javascript-practice && npm run test-once:b",
+    "test-once:c": "cd javascript-practice && npm run test-once:c",
+    "test-once:d": "cd javascript-practice && npm run test-once:d",
+    "test-once:e": "cd javascript-practice && npm run test-once:e",
+    "test-once:f": "cd javascript-practice && npm run test-once:f",
+    "test-once:g": "cd javascript-practice && npm run test-once:g",
+    "test-once:h": "cd javascript-practice && npm run test-once:h",
+    "test-once:i": "cd javascript-practice && npm run test-once:i",
+    "test-once:j": "cd javascript-practice && npm run test-once:j",
+    "test-once:k": "cd javascript-practice && npm run test-once:k",
+    "test-once:l": "cd javascript-practice && npm run test-once:l",
+    "test-once:m": "cd javascript-practice && npm run test-once:m",
+    "test-once:n": "cd javascript-practice && npm run test-once:n",
+    "test-once:o": "cd javascript-practice && npm run test-once:o",
+    "test-once:p": "cd javascript-practice && npm run test-once:p",
+    "test-once:q": "cd javascript-practice && npm run test-once:q",
+    "test-once:r": "cd javascript-practice && npm run test-once:r",
+    "test-once:s": "cd javascript-practice && npm run test-once:s",
+    "test-once": "cd javascript-practice && npm run test-once",
+    "test": "run-s test-once"
+  },
+  "devDependencies": {
+    "ghooks": "^2.0.4",
+    "npm-run-all": "^4.1.5"
+  }
+}