Puissance 4 (Connect Four) in command line on Node.js

A command line program with Node.js, chalk (for terminal string styling) and readline-sync (for interactive conversation with the user via a console).

Presentation

• src/main.js : manages game;
• src/grid.js : builds grid depending on a number of columns and rows (recommended maximum 40 columns and 99 rows for user experience);
• src/checkImpossible.js : function to check if impossible game (due to number of rows, columns or tokens to align);
• src/checkWinner.js : functions to check for horizontal, vertical or diagonal win;
• src/help.js : function for help option;
• src/rules.js : function to show rules;

Install dependencies:

% yarn install

Play

Using the command line 2 players take turns to place tokens on a grid. By default the grid has 6 rows and 7 columns (but this can be changed in src/grid.js):

      1   2   3   4   5   6   7
    +---+---+---+---+---+---+---+
  6 |   |   |   |   |   |   |   |
    +---+---+---+---+---+---+---+
  5 |   |   |   |   |   |   |   |
    +---+---+---+---+---+---+---+
  4 |   |   |   |   |   |   |   |
    +---+---+---+---+---+---+---+
  3 |   |   |   |   |   |   |   |
    +---+---+---+---+---+---+---+
  2 |   |   | O |   |   |   |   |
    +---+---+---+---+---+---+---+
  1 |   |   | X |   |   |   |   |
    +---+---+---+---+---+---+---+
      1   2   3   4   5   6   7

  Mihai> put(1)

Launch

node src/main.js

Program asks for the names of the two players and attributes to the first a red token O and to the second a yellow token X.
The game can begin.
Below the grid a prompt invites current player to enter one of the folloing commands :

Mihai> put(1)=> Place a token of player Mihai in column 1.
Mihai> rules => Show game rules.
Mihai> help => Show all available commands.
Mihai> whoami => Show token of current player.
Mihai> abandon => Player abandons and the other player is declared winner.

The game ends whenever a player wins by making a horizontal, vertical or diagonal line of 4 tokens (by default but this can be changed in src/grid.js) or in case of a draw when all tokens are placed without a winner.