HexGrid.map

src/hexgrid.ts

@@ -6,12 +6,7 @@ export class Hex<T = void> {
  readonly y: number;
  content: T | undefined;
 
- constructor(
- parent: HexGrid<T>,
- x: number,
- y: number,
- initializeFn?: InitHexFn<T>,
- ) {
+ constructor(parent: HexGrid<T>, x: number, y: number, initializeFn?: InitHexFn<T>) {
  this.parent = parent;
  this.x = x;
  this.y = y;
@@ -27,8 +22,8 @@ export class HexGrid<T = void> {
  private readonly hexArray: Hex<T>[][]
 
  constructor(
- width: number,
- height: number,
+ private width: number,
+ private height: number,
  initializeFn?: InitHexFn<T>,
  ) {
  this.hexArray = Array.from(new Array(height))
@@ -68,4 +63,16 @@ export class HexGrid<T = void> {
  ]
  .filter(hex => hex !== undefined);
  }
+
+ map<U>(mappingFunction: (x: Hex<T>) => U): HexGrid<U> {
+ const originalHex = (hex: Hex<unknown>) => {
+ return this.at(hex.x, hex.y);
+ }
+
+ return new HexGrid<U>(
+ this.width,
+ this.height,
+ (hex) => mappingFunction(originalHex(hex))
+ );
+ }
 }

tests/hexgrid.spec.ts

@@ -176,6 +176,43 @@ describe('a hex grid', () => {
  expect(grid.at(2, 2).content).to.eql('2,2');
  });
  });
+
+ describe('mapping over the grid', () => {
+ it('returns a new grid with the mapped values', () => {
+ fc.assert(fc.property(fc.anything(), thing => {
+ const originalGrid = new HexGrid<string>(1, 1, () => '');
+ const grid = originalGrid.map(() => thing);
+
+ expect(grid.at(0, 0).content).to.eql(thing);
+ }));
+ });
+
+ it('passes the original hex properties into the function', () => {
+ fc.assert(fc.property(fc.anything(), fc.anything(), (thing, thing2) => {
+ const originalGrid = new HexGrid<unknown>(3, 3, () => thing);
+ const grid = originalGrid.map((hex) => `${hex.x},${hex.y}`);
+
+ expect(grid.at(0, 0).content).to.eql('0,0');
+ expect(grid.at(1, 0).content).to.eql('1,0');
+ expect(grid.at(2, 0).content).to.eql('2,0');
+ expect(grid.at(0, 1).content).to.eql('0,1');
+ expect(grid.at(1, 1).content).to.eql('1,1');
+ expect(grid.at(2, 1).content).to.eql('2,1');
+ expect(grid.at(0, 2).content).to.eql('0,2');
+ expect(grid.at(1, 2).content).to.eql('1,2');
+ expect(grid.at(2, 2).content).to.eql('2,2');
+ }));
+ });
+
+ it('passes the original hex content into the function', () => {
+ fc.assert(fc.property(fc.anything(), fc.anything(), (thing, thing2) => {
+ const originalGrid = new HexGrid<unknown>(1, 1, () => thing);
+ const grid = originalGrid.map((x) => `${JSON.stringify(x.content)}|${JSON.stringify(thing2)}`);
+
+ expect(grid.at(0, 0).content).to.eql(`${JSON.stringify(thing)}|${JSON.stringify(thing2)}`);
+ }));
+ });
+ });
 });
 
 describe('a hex', () => {