Draw unicode square grid

unicodeSquareGrid.js

const GRID_PARTS_VARIANT_LIGHT = 'LIGHT';
const GRID_PARTS_VARIANT_DOUBLE = 'DOUBLE';

const GRID_PART_VARIANTS_DICTIONARY = {
  [GRID_PARTS_VARIANT_LIGHT]: '─│┌┐└┘├┤┬┴┼',
  [GRID_PARTS_VARIANT_DOUBLE]: '═║╔╗╚╝╠╣╦╩╬'
};

/**
 * Create grid parts mapping object
 * @param gridPartsString
 * @returns object
 */
const getGridPartsFromPartVariantsDictionaryString = (gridPartsString) => {
  const [
    HORIZONTAL,
    VERTICAL,
    DOWN_RIGHT,
    DOWN_LEFT,
    UP_RIGHT,
    UP_LEFT,
    VERTICAL_RIGHT,
    VERTICAL_LEFT,
    DOWN_HORIZONTAL,
    UP_HORIZONTAL,
    VERTICAL_HORIZONTAL,
  ] = gridPartsString.split('');
  return {
    HORIZONTAL,
    VERTICAL,
    DOWN_RIGHT,
    DOWN_LEFT,
    UP_RIGHT,
    UP_LEFT,
    VERTICAL_RIGHT,
    VERTICAL_LEFT,
    DOWN_HORIZONTAL,
    UP_HORIZONTAL,
    VERTICAL_HORIZONTAL
  };
};

/**
 * Draw the grid
 * @param gp Grid parts
 * @param dd Drawing depth
 * @param cx Current X position
 * @param cy Current Y position
 * @param fd Final drawing string
 * @returns string
 */
const drawGrid = (gp, dd, cx = 0, cy = 0, fd = '') => {
  if (dd < 1 || cx > dd || cy > dd) {
    return fd;
  }

  if (cx === 0 && cy === 0) {
    cx++;
    fd = fd + gp.DOWN_RIGHT + gp.HORIZONTAL;
  } else if (cx === dd && cy === 0) {
    cx = 0;
    cy++;
    fd = fd + gp.HORIZONTAL + gp.DOWN_LEFT + "\n";
  } else if (cx === 0 && cy === dd) {
    cx++;
    fd = fd + gp.UP_RIGHT + gp.HORIZONTAL;
  } else if (cx === dd && cy === dd) {
    cx++;
    cy++;
    fd = fd + gp.HORIZONTAL + gp.UP_LEFT + "\n";
  } else if (cx < dd && cy === 0) {
    cx++;
    fd = fd + gp.HORIZONTAL + gp.DOWN_HORIZONTAL + gp.HORIZONTAL;
  } else if (cx < dd && cy === dd) {
    cx++;
    fd = fd + gp.HORIZONTAL + gp.UP_HORIZONTAL + gp.HORIZONTAL;
  } else if (cx === 0 && cy < dd) {
    cx++;
    fd = fd + gp.VERTICAL_RIGHT + gp.HORIZONTAL;
  } else if (cx === dd && cy < dd) {
    cx = 0;
    cy++;
    fd = fd + gp.HORIZONTAL + gp.VERTICAL_LEFT + "\n";
  } else if (cx < dd && cy < dd) {
    cx++;
    fd = fd + gp.HORIZONTAL + gp.VERTICAL_HORIZONTAL + gp.HORIZONTAL;
  }

  return drawGrid(gp, dd, cx, cy, fd);
};

Use case:

const unicodeGridDepth3Light = drawGrid(
  getGridPartsFromPartVariantsDictionaryString(GRID_PART_VARIANTS_DICTIONARY.LIGHT), 3
);
const unicodeGridDepth5Double = drawGrid(
  getGridPartsFromPartVariantsDictionaryString(GRID_PART_VARIANTS_DICTIONARY.DOUBLE), 5
);
console.log(unicodeGridDepth3Light);
console.log(unicodeGridDepth5Double);

Result:

┌──┬──┬──┐
├──┼──┼──┤
├──┼──┼──┤
└──┴──┴──┘

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