ThomasBurleson

💚 Best Practices: Use Permissions as BitFlags

Developers often miss the opportunity to express permissions as a collection of enumerated bitflags; where complex permissions can be easily grouped by context.

Consider the scenario where a user may have 30 or more permission flags.

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Improved Version 😄:

ThomasBurleson

💚 Best Practices: Avoid 3 Common RxJS Issues

Bad-RxJS Issues

Developers often find scenarios where they are compelled to manaully subscribe to Observables in View components; these scenarios do not use the async pipe levels of manual subscription management. These manual subscriptions can lead to:

• Observables + memory leaks, and
• Zombie subscriptions

ThomasBurleson

/**
 *  When manually subscribing to an observable in a view component, developers are traditionally required
 *  to unsubscribe during ngOnDestroy. This utility method auto-configures and manages that relationship
 *  by watching the DOM with a MutationObserver and internally using the takeUntil RxJS operator.
 *
 *  Angular 7 has stricter enforcements and throws errors with monkey-patching of view component life-cycle methods.
 *  Here is an updated version that uses MutationObserver to accomplish the  same goal.
 *
 *  @code
 *

ThomasBurleson

NgRx State Management with TicketFacade

Facades are a programming pattern in which a simpler public interface is provided to mask a composition of internal, more-complex, component usages.

When writing a lot of NgRx code - as many enterprises do - developers quickly accumulate large collections of actions and selectors classes. These classes are used to dispatch and query [respectively] the NgRx Store.

Using a Facade - to wrap and blackbox NgRx - simplifies accessing and modifying your NgRx state by masking internal all interactions with the Store, actions, reducers, selectors, and effects.

For more introduction, see Better State Management with Ngrx Facades

ThomasBurleson

ES6 Curry Function

const curry = (fn, ...cache) => (...args) => {
  const all = cache.concat(args);
  return all.length >= fn.length ? fn(...all) : curry(fn, ...all);
};

Example

ThomasBurleson

Typical coding example for a sequence of asynchronous REST calls:

function update(ev, updateDiff) {
  // get current event from Back End
  return scheduleService.getEvent(ev.id).then(function(event) {
    // send updates to Back end
    return scheduleService.editEvent(ev.id, event.version, updateDiff).then(function(evt) {
 var pack = findAircraftPackById(evt.aircraft.id);

ThomasBurleson

Commit Message Conventions

These rules are adopted from the Angular commit conventions.

• Goals
• Generating CHANGELOG.md
  • Recognizing unimportant commits
  • Provide more information when browsing the history
• Format of the commit message
• Subject line

ThomasBurleson

# remove local tag
git tag -d tagname-123
# remove remote tag
git push origin :refs/tags/tagname-123

# delete multiple tags by patterns
for tag in $(git tag -l '[production|tusur]*'); do git tag -d $tag; git push origin :refs/tags/$tag; done

ThomasBurleson

The interview questions below are grouped by category and each category lists questions in easy-to-hard order.

Interviews should ask the candidate to self-assess their skills/experience. Based on the candidate's response, the interviewer can jump to the appropriate section.

Some basic questions going from easy to difficult. A more exhaustive list of more questions from the community can be found here.

JavaScript

• What is variable shadowing

ThomasBurleson

import {Component, OnInit} from '@angular/core';
import {ActivatedRoute} from '@angular/router';
import {ContactsService} from '../contacts.service';
import {Contact} from '../models/contact';

import 'rxjs/add/operator/switchMap';
import {Subscription} from 'rxjs';

@Component({
  selector: 'trm-contacts-detail',