ivan7237d/1log-rxjs

1log plugin for logging RxJS observables

Warning

This package has been deprecated in favor of @1log/rxjs.

1log-rxjs

1log plugin for logging RxJS observables. Please see an article Log and test RxJS observables with 1log for an introduction.

Installing

💡 TIP

If you just need to quickly install the library to play around with it, install packages 1log and 1log-rxjs and add the following imports:

import '1log/defaultConfig';
import '1log-rxjs/defaultConfig';
import { log } from '1log';

Assuming you have RxJS installed,

1. Install 1log.

2. Install the npm package:

   yarn add 1log-rxjs
   

   or

   npm install 1log-rxjs --save
   

3. Where you import '1log/defaultConfig', also import '1log-rxjs/defaultConfig', which runs installPlugins(statePlugin). Where you import '1log/defaultJestConfig', also import '1log-rxjs/defaultJestConfig', which is the same as importing a file with the following contents:

   import { installPlugins } from '1log';
   import { observablePlugin } from '1log-rxjs';
   import { Observable } from 'rxjs';
   
   // Add a serializer for observables.
   expect.addSnapshotSerializer({
     test: (value) =>
       value !== null &&
       value !== undefined &&
       value.constructor === Observable,
     serialize: () => `[Observable]`,
   });
   
   // Add a serializer for subscribers.
   expect.addSnapshotSerializer({
     test: (value) => value instanceof Subscriber,
     serialize: () => `[Subscriber]`,
   });
   
   installPlugins(observablePlugin);

Usage

import { log } from '1log';
import { timer } from 'rxjs';

timer(500).pipe(log).subscribe();

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This plugin logs Observables but not instances of classes inheriting from Observable. If you need to log a subject, first convert it to an observable using asObservable method.

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In Chrome, you can right-click an observable or a subscriber from a create/subscribe log message and say "Store as global variable". The object will be stored with a name like temp1, and you'll be able to run temp1.subscribe() (observable) or temp1.next(yourValue) / temp1.error(yourError) / temp1.complete() (subscriber).

Usage in tests

import { getMessages, log } from '1log';
import { timer } from 'rxjs';

test('timer', () => {
  timer(500).pipe(log).subscribe();
  jest.runAllTimers();
  expect(getMessages()).toMatchInlineSnapshot(`
    [create 1] +0ms [Observable]
    [create 1] [subscribe 1] +0ms [Subscriber]
    [create 1] [subscribe 1] [next 1] +500ms 0
    [create 1] [subscribe 1] [complete] +0ms
    · [create 1] [subscribe 1] [unsubscribe] +0ms
  `);
});

💡 TIP

In older versions of RxJS you had to use TestScheduler in tests, but since version 6.2.1, RxJS works well with Jest's fake time.

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Contributing guidelines