JS Adagrams

Skills Assessed

• Writing Javascript functions with correct syntax, including:
  • only use const and let variables
  • use semi-colons where needed
  • name variables and functions with camelCase
• Practicing good git hygiene:
  • make at least three small commits with meaningful commit messages
• Practicing TDD with JavaScript and the Jest testing framework

Goal

In this project, we will build the same Adagrams project from the Python curriculum using JavaScript running on Node.js in the terminal. Please review the original project for an explanation of the Adagrams game design.

A test suite and sample game project is provided in order to practice TDD and verify the correct implementation. A complete project will pass all of the provided tests and have coverage of at least 90%.

Note there are a handful of incomplete tests that currently throw exceptions. You should complete these tests and remove the exception.

Getting Started

After forking and cloning this repo you should cd to the project directory and run:

$ npm install

Similar to using virtual environments in Python projects, this makes the Node Package Manager (npm) download and install any dependencies for the project (such as Jest).

When I npm install, I Get a Lot of Text: What Do I Do?!

Managing external dependencies (packages/libraries that we use) in JavaScript projects is different than managing them in Python. In JavaScript, we use npm to manage dependencies, and those dependencies have other dependencies. Our dependencies may change over time, and those dependency's dependencies change, too! It's a lot.

When we run npm install, npm may give us a lot of feedback about the state of our dependencies.

If we get warnings about vulnerabilities, it's likely that we won't worry about them, even if they're high risk or even if they're many (thousands?!).

If we get a message about gyp: No Xcode or CLT version, we also won't worry about it. That error is because of changing operating systems. You are free to do some independent research to fix this if you're excited, though!.

The important thing is if we are able to run the tests. After running npm install, follow the directions in the next section to run the tests. If your tests run and fail, then that's a great place to be! If your tests won't run, then you should seek help.

Tests

We have provided unit tests for you to run. As a reminder, a few of these unit tests are incomplete and currently throw exceptions. You should complete any incomplete tests and remove the exception. A complete project will pass all provided tests in the test/adagrams.test.js file. The other tests are for game logic that is provided and they may pass or fail depending upon the state of your code. However, you should focus on just the tests in test/adagrams.test.js.

To run the tests, in the command line, navigate to the project root and then run:

$ npm test test/adagrams.test.js

After the tests run, there is a short table that summarizes the coverage for each file. You can view complete coverage details by running:

$ npm run coverage

This is shorthand for the command open coverage/lcov-report/index.html and will open the coverage report in your default web browser.

Adagrams Demo Game

In addition to the provided unit tests, we provided a demo game application that uses Adagrams code that you will implement. You can play the game as you implement each wave of the project and verify that game functionality begins to work, in addition to passing unit tests. Don't forget; making the demo game work is optional-- passing the unit tests is required.

For more details on how to run the demo game, click here!

You can start the demo game application with the following command:

$ npm run demo-game

This will start the Adagrams prompt, and you can start a new game by typing start (or start <num> for a game with multiple players). To exit the game you can either enter exit (you will have to enter this a few times) or press Control + C twice.

Once the game has started each player is prompted to play anagrams from the displayed letter bank until their turn completes. At the end of each round the player who played the best word (according to the logic you will implement in wave 4) is awarded points based on that word. Once all rounds are completed the game announced who won with the point total for that player.

The game is fairly rudimentary and has a few bugs remaining, such as needing to type 'exit' to complete your turn. If you've completed all of the waves for this project and wish to continue working on terminal JavaScript code, feel free to ask your instructors for suggestions on bug fixes or improvements to make for the game code.

Conclusion

Just like our Python Adagrams project, we will only build the library code that captures all of the rules. We can use this demo game code to imagine how another program may hook into our codebase for logic.

Project Structure

This repository has a baseline structure for the project that includes several files. You will only need to modify one of them:

File	Description
src/adagrams.js	This is the project code, your implementation should complete each of the functions. Each function is exported.
test/adagrams.test.js	This file contains the unit tests for all functions you must implement. This file imports the functions from adagrams.js. This file also contains tests that you will need to complete.
package.json	This is the npm project description file for this project. It includes all of the dependencies, much like requirements.txt in our Python projects. It can also include other information such as scripts, descriptions, project versions, etc.
package-lock.json	package-lock.json captures the exact dependency tree stored at any point in time.
jest.config.js	This is a configuration file for the Jest testing framework.
babel.config.js	This is a configuration file for the Babel compiler.

Implementation Requirements

Wave 1

Our first job is to build a hand of 10 letters. To do so, implement the function named drawLetters in src/adagrams.js. This function should have the following properties:

• No parameters
• Returns an array of ten strings
  • Each string should contain exactly one letter
  • These represent the hand of letters that the player has drawn
• The letters should be randomly drawn from a pool of letters
  • This letter pool should reflect the distribution of letters as described in the table below
  • There are only 2 available C letters, so drawLetters cannot ever return more than 2 Cs
  • Since there are 12 Es but only 1 Z, it should be 12 times as likely to draw an E as a Z
• Invoking this function should not change the pool of letters
  • Imagine that the user returns their hand to the pool before drawing new letters

Distribution of Letters

Letter : Qty.	Letter : Qty.
A : 9	N : 6
B : 2	O : 8
C : 2	P : 2
D : 4	Q : 1
E : 12	R : 6
F : 2	S : 4
G : 3	T : 6
H : 2	U : 4
I : 9	V : 2
J : 1	W : 2
K : 1	X : 1
L : 4	Y : 2
M : 2	Z : 1

Note: Making sure that the drawn letters match the rules of the letter pool can be straightforward or very difficult, depending on how you build the data structure for the letter pool. It is worth spending some time to think carefully about this.

Wave 2

Next, we need a way to check if an input word (a word a player submits) only uses characters that are contained within a collection (or hand) of drawn letters. Essentially, we need a way to check if the word is, indeed, an anagram of some or all of the given letters in the hand.

To do so, implement the function named usesAvailableLetters in src/adagrams.js. This function should have the following properties:

• Has two parameters:
  • input, the first parameter, describes some input word, and is a string
  • lettersInHand, the second parameter, describes an array of drawn letters in a hand. You can expect this to be an array of ten strings, with each string representing a letter
• Returns either true or false
• Returns true if every letter in the input word is available (in the right quantities) in the lettersInHand
• Returns false if not; if there is a letter in input that is not present in the lettersInHand or has too much of compared to the lettersInHand

Wave 3

We want a function that returns the score of a given word as defined by the Adagrams game.

Implement the function named scoreWord in src/adagrams.js. This method should have the following properties:

• Has one parameter: word, which is a string of characters
• Returns an integer representing the number of points
• Each letter within word has a point value. The number of points of each letter is summed up to represent the total score of word
• Each letter's point value is described in the table below
• If the length of the word is 7, 8, 9, or 10, then the word gets an additional 8 points

Score chart

Letter	Value
A, E, I, O, U, L, N, R, S, T	1
D, G	2
B, C, M, P	3
F, H, V, W, Y	4
K	5
J, X	8
Q, Z	10

Wave 4

After several hands have been drawn, words have been submitted, checked, scored, and played, we want a way to find the highest scoring word. This function looks at the array of words and calculates which of these words has the highest score, applies any tie-breaking logic, and returns the winning word in a special data structure.

Objective

Implement the function named highestScoreFrom in src/adagrams.js. This method should have the following properties:

• Has one parameter: words, which is an array of strings
• Returns a single object that represents the data of a winning word and its score. The object should have the following keys:
  • word, whose value is a string of a word
  • score, whose value is the score of that word
• In the case of tie in scores, use these tie-breaking rules:
  • prefer the word with the fewest letters...
  • ...unless one word has 10 letters. If the top score is tied between multiple words and one is 10 letters long, choose the one with 10 letters over the one with fewer tiles
  • If the there are multiple words that are the same score and the same length, pick the first one in the supplied list