sodiumjs/src/tests/unit/CellSink.spec.ts

A Functional Reactive Programming (FRP) library for JavaScript

import {
  Cell,
  StreamSink,
  CellSink,
  Transaction,
  Tuple2,
  getTotalRegistrations
} from '../../lib/Lib';

afterEach(() => {
  if (getTotalRegistrations() != 0) {
    throw new Error('listeners were not deregistered');
  }
});

test('should test snapshot', (done) => {
  const c = new CellSink<number>(0),
    s = new StreamSink<number>(),
    out: string[] = [],
    kill = s.snapshot(c, (x, y) => x + " " + y)
      .listen(a => {
        out.push(a);
        if (out.length === 3) {
          done();
        }
      });

  s.send(100);
  c.send(2);
  s.send(200);
  c.send(9);
  c.send(1);
  s.send(300);
  kill();

  expect(["100 0", "200 2", "300 1"]).toEqual(out);
});

test('should test values', (done) => {
  const c = new CellSink<number>(9),
    out: number[] = [],
    kill = c.listen(a => {
      out.push(a);
      if (out.length === 3) {
        done();
      }
    });

  c.send(2);
  c.send(7);
  kill();

  expect([9, 2, 7]).toEqual(out);
});

test("should test mapC", (done) => {
  const c = new CellSink<number>(6),
    out: string[] = [],
    kill = c.map(a => "" + a)
      .listen(a => {
        out.push(a);
        if (out.length === 2) {
          done();
        }
      });
  c.send(8);
  kill();

  expect(["6", "8"]).toEqual(out);
});

test("should throw an error on mapCLateListen", () => {
  const c = new CellSink<number>(6),
  out: string[] = [],
  cm = c.map(a => "" + a);

  try {
    c.send(2);
    const kill = cm.listen(a => out.push(a));
    c.send(8);
    kill();
  } catch(e) {

    expect(e.message).toBe('send() was invoked before listeners were registered');
  }

  //assertEquals(["2", "8"], out);
});

test("should test apply", (done) => {
  const cf = new CellSink<(a: number) => string>(a => "1 " + a),
    ca = new CellSink<number>(5),
    out: string[] = [],
    kill = Cell.apply(cf, ca).listen(a => {
      out.push(a);
      if (out.length === 3) {
        done();
      }
    });

  cf.send(a => "12 " + a);
  ca.send(6);
  kill();

  expect(["1 5", "12 5", "12 6"]).toEqual(out);
});

test("should test lift", (done) => {
  const a = new CellSink<number>(1),
    b = new CellSink<number>(5),
    out: string[] = [],
    kill = a.lift(b, (aa, bb) => aa + " " + bb)
      .listen(a => {
        out.push(a);
        if (out.length === 3) {
          done();
        }
      });
  a.send(12);
  b.send(6);
  kill();

  expect(["1 5", "12 5", "12 6"]).toEqual(out);
});

test("should test liftGlitch", (done) => {
  const a = new CellSink(1),
    a3 = a.map(x => x * 3),
    a5 = a.map(x => x * 5),
    b = a3.lift(a5, (x, y) => x + " " + y),
    out: string[] = [],
    kill = b.listen(x => {
      out.push(x);
      if (out.length === 2) {
        done();
      }

    });
  a.send(2);
  kill();

  expect(["3 5", "6 10"]).toEqual(out);
});

test("should test liftFromSimultaneous", (done) => {
  const t = Transaction.run(() => {
    const b1 = new CellSink(3),
      b2 = new CellSink(5);
    b2.send(7);
    return new Tuple2(b1, b2);
  });

  const b1 = t.a,
    b2 = t.b,
    out: number[] = [],
    kill = b1.lift(b2, (x, y) => x + y)
      .listen(a => {
        out.push(a);
        done();
      });
  kill();

  expect([10]).toEqual(out);
});