Initial hexgrid

package.json

@@ -9,7 +9,9 @@
  "author": "",
  "license": "ISC",
  "devDependencies": {
+ "@types/chai": "^4.3.0",
  "@types/mocha": "^9.0.0",
+ "chai": "^4.3.4",
  "mocha": "^9.1.3",
  "ts-node": "^10.4.0",
  "typescript": "^4.5.4"

tests/hexgrid.spec.ts

@@ -0,0 +1,61 @@
+import { describe, it } from "mocha";
+import { expect } from "chai";
+
+class Hex {
+ private readonly parent: HexGrid;
+ private readonly x: number;
+ private readonly y: number;
+
+ constructor(parent: HexGrid, x: number) {
+ this.parent = parent;
+ this.x = x;
+ this.y = 0;
+ }
+
+ get neighbors(): Hex[] {
+ return this.parent.neighborsOf(this.x, this.y);
+ }
+}
+
+class HexGrid {
+ private readonly hexArray: Hex[]
+
+ constructor(width: number, height: number) {
+ const size = width * height;
+ this.hexArray = Array.from(new Array(size)).map((_, x) => new Hex(this, x));
+ }
+
+ at(x: number, y: number): Hex {
+ return this.hexArray[x];
+ }
+
+ neighborsOf(x: number, y: number): Hex[] {
+ const left = x - 1;
+ const right = x + 1;
+
+ return [this.hexArray[left], this.hexArray[right]]
+ .filter(hex => hex !== undefined);
+ }
+}
+
+describe('a hex grid', () => {
+ describe('with a single hex', () => {
+ it('has no neighbors', () => {
+ const grid = new HexGrid(1, 1);
+ const hex = grid.at(0,0);
+ expect(hex.neighbors).to.be.empty;
+ });
+ });
+
+ describe('a completely horizontal map', () => {
+ it('has neighbors left and right of tiles', () => {
+ const grid = new HexGrid(5, 1);
+
+ expect(grid.at(0,0).neighbors).to.have.members([grid.at(1,0)]);
+ expect(grid.at(1,0).neighbors).to.have.members([grid.at(0,0), grid.at(2,0)]);
+ expect(grid.at(2,0).neighbors).to.have.members([grid.at(1,0), grid.at(3,0)]);
+ expect(grid.at(3,0).neighbors).to.have.members([grid.at(2,0), grid.at(4,0)]);
+ expect(grid.at(4,0).neighbors).to.have.members([grid.at(3,0)]);
+ });
+ });
+});