mobx-utils/test/from-resource.js

"use strict";

const utils = require("../src/mobx-utils");
const mobx = require("mobx");

mobx.configure({ enforceActions: true });

function Record(name) {
  this.data = { name: name };
  this.subscriptions = [];
}
Record.prototype.updateName = function(newName) {
  this.data.name = newName;
  this.subscriptions.forEach(f => f());
};
Record.prototype.subscribe = function(cb) {
  this.subscriptions.push(cb);
  return () => {
    const idx = this.subscriptions.indexOf(cb);
    if (idx !== -1);
    this.subscriptions.splice(idx, 1);
  };
};

function createObservable(record) {
  let subscription;
  return utils.fromResource(
    sink => {
      sink(record.data);
      subscription = record.subscribe(() => {
        sink(record.data);
      });
    },
    () => subscription()
  );
}

test("basics", () => {
  let base = console.warn; // eslint-disable-line no-console
  let warn = [];
  console.warn = msg => warn.push(msg); // eslint-disable-line no-console

  var me = new Record("michel");
  var me$ = createObservable(me);
  expect(me.subscriptions.length).toBe(0);

  var currentName;
  var calcs = 0;
  var disposer = mobx.autorun(() => {
    calcs++;
    currentName = me$.current().name;
  });

  expect(me.subscriptions.length).toBe(1);
  expect(currentName).toBe("michel");
  me.updateName("veria");
  expect(currentName).toBe("veria");
  me.updateName("elise");
  expect(currentName).toBe("elise");
  expect(calcs).toBe(3);

  disposer();
  expect(me.subscriptions.length).toBe(0);

  me.updateName("noa");
  expect(currentName).toBe("elise");
  expect(calcs).toBe(3);

  // test warning
  expect(me$.current().name).toBe("noa"); // happens to be visible through the data reference, but no autorun tragger
  expect(warn).toEqual([
    "Called `get` of an subscribingObservable outside a reaction. Current value will be returned but no new subscription has started"
  ]);

  // resubscribe
  disposer = mobx.autorun(() => {
    calcs++;
    currentName = me$.current().name;
  });

  expect(currentName).toBe("noa");
  expect(calcs).toBe(4);

  setTimeout(() => {
    expect(me.subscriptions.length).toBe(1);
    me.updateName("jan");
    expect(calcs).toBe(5);

    me$.dispose();
    expect(me.subscriptions.length).toBe(0);
    expect(() => me$.current()).toThrow();

    me.updateName("john");
    expect(calcs).toBe(5);
    expect(currentName).toBe("jan");

    disposer(); // autorun

    expect(warn.length).toBe(1);
    console.warn = base; // eslint-disable-line no-console
    done();
  }, 100);
});

test("from computed, #32", () => {
  var you = new Record("You");
  var you$ = createObservable(you);

  var computedName = mobx.computed(() => you$.current().name.toUpperCase());
  var name;
  var d = mobx.autorun(() => (name = computedName.get()));
  expect(name).toBe("YOU");
  you.updateName("Me");
  expect(name).toBe("ME");
  d();
  you.updateName("Hi");
  expect(name).toBe("ME");
});