excalidraw/src/element/bounds.test.ts

import { getElementAbsoluteCoords, getElementBounds } from "./bounds";
import { ExcalidrawElement, ExcalidrawLinearElement } from "./types";

const _ce = ({
  x,
  y,
  w,
  h,
  a,
  t,
}: {
  x: number;
  y: number;
  w: number;
  h: number;
  a?: number;
  t?: string;
}) =>
  ({
    type: t || "rectangle",
    strokeColor: "#000",
    backgroundColor: "#000",
    fillStyle: "solid",
    strokeWidth: 1,
    roughness: 0,
    opacity: 1,
    x,
    y,
    width: w,
    height: h,
    angle: a,
  } as ExcalidrawElement);

describe("getElementAbsoluteCoords", () => {
  it("test x1 coordinate", () => {
    const [x1] = getElementAbsoluteCoords(_ce({ x: 10, y: 0, w: 10, h: 0 }));
    expect(x1).toEqual(10);
  });

  it("test x2 coordinate", () => {
    const [, , x2] = getElementAbsoluteCoords(
      _ce({ x: 10, y: 0, w: 10, h: 0 }),
    );
    expect(x2).toEqual(20);
  });

  it("test y1 coordinate", () => {
    const [, y1] = getElementAbsoluteCoords(_ce({ x: 0, y: 10, w: 0, h: 10 }));
    expect(y1).toEqual(10);
  });

  it("test y2 coordinate", () => {
    const [, , , y2] = getElementAbsoluteCoords(
      _ce({ x: 0, y: 10, w: 0, h: 10 }),
    );
    expect(y2).toEqual(20);
  });
});

describe("getElementBounds", () => {
  it("rectangle", () => {
    const [x1, y1, x2, y2] = getElementBounds(
      _ce({ x: 40, y: 30, w: 20, h: 10, a: Math.PI / 4, t: "rectangle" }),
    );
    expect(x1).toEqual(39.39339828220179);
    expect(y1).toEqual(24.393398282201787);
    expect(x2).toEqual(60.60660171779821);
    expect(y2).toEqual(45.60660171779821);
  });

  it("diamond", () => {
    const [x1, y1, x2, y2] = getElementBounds(
      _ce({ x: 40, y: 30, w: 20, h: 10, a: Math.PI / 4, t: "diamond" }),
    );
    expect(x1).toEqual(42.928932188134524);
    expect(y1).toEqual(27.928932188134524);
    expect(x2).toEqual(57.071067811865476);
    expect(y2).toEqual(42.071067811865476);
  });

  it("ellipse", () => {
    const [x1, y1, x2, y2] = getElementBounds(
      _ce({ x: 40, y: 30, w: 20, h: 10, a: Math.PI / 4, t: "ellipse" }),
    );
    expect(x1).toEqual(42.09430584957905);
    expect(y1).toEqual(27.09430584957905);
    expect(x2).toEqual(57.90569415042095);
    expect(y2).toEqual(42.90569415042095);
  });

  it("curved line", () => {
    const [x1, y1, x2, y2] = getElementBounds({
      ..._ce({
        t: "line",
        x: 449.58203125,
        y: 186.0625,
        w: 170.12890625,
        h: 92.48828125,
        a: 0.6447741904932416,
      }),
      points: [
        [0, 0] as [number, number],
        [67.33984375, 92.48828125] as [number, number],
        [-102.7890625, 52.15625] as [number, number],
      ],
    } as ExcalidrawLinearElement);
    expect(x1).toEqual(360.3176068760539);
    expect(y1).toEqual(185.90654264413516);
    expect(x2).toEqual(480.87005902729743);
    expect(y2).toEqual(320.4751269334226);
  });
});