import { eulerFull, eulerStep } from '../EulerMethod' describe('eulerStep', () => { it('should calculate the next y value correctly', () => { expect( eulerStep(0, 0.1, 0, function (x, y) { return x }) ).toBe(0) expect( eulerStep(2, 1, 1, function (x, y) { return x * x }) ).toBe(5) }) }) describe('eulerFull', () => { it('should return all the points found', () => { expect( eulerFull(0, 3, 1, 0, function (x, y) { return x }) ).toEqual([ { x: 0, y: 0 }, { x: 1, y: 0 }, { x: 2, y: 1 }, { x: 3, y: 3 } ]) expect( eulerFull(3, 4, 0.5, 1, function (x, y) { return x * x }) ).toEqual([ { x: 3, y: 1 }, { x: 3.5, y: 5.5 }, { x: 4, y: 11.625 } ]) }) })