Gleb Bahmutov PRO
JavaScript ninja, image processing expert, software quality fanatic
-
Cypress Test Parallelization and Grouping
Intro to end-to-end test parallelization and grouping with Cypress Dashboard service. Part of Cypress webinar on October 16 2018
-
Cypress Intro
A quick introduction to Cypress.io end-to-end test runner.
-
End-vue-End Testing
Testing Vue applications can be quick and painless. In this presentation, I will show how to test small parts of Vue apps using vue-test-utils, and how to move "up" the testing pyramid to component and end-to-end tests using Cypress. Presented at VueNYC meetup in Sept 2018.
-
Semantic Release
Manually releasing new software versions is dangerous. You might forget to test it before releasing, or you might release a platform-specific version, instead of a general one. Moving the release to the CI and automating it is the key to the repeatable and robust release process. In this talk, I will show how to set up a completely automated yet robust release system with semantic versioning for JavaScript using NodeJS. Presented at VermontCodeCamp 2018.
-
JSON Schemas are your True Testing Friend
In our company we have a lot of data flowing from the user’s applications (and we are backwards compatible) to the API, then this data is displayed in the web dashboard. How do we avoid accidentally breaking API contracts, while adding new features? We have started using json-schema convention and wrote a few tools around it to lock down our API protocols. Now we have full confidence in our tests, and major refactoring and releases happen without hiccups. Bonus: our tests are realistic, elegant and easy to understand. Presented at Boston JS meetup.
-
Painless Testing for Modern Web Applications with Cypress.io
This presentation showcases Cypress.io - an open source, MIT-licensed end-to-end test runner that radically break with existing technologies (like Selenium, WebDriver) to be able to test _modern_ web applications. The main focus of Cypress is to give every developer a tool that helps rather than hinders the development process. Thus it has such features as GUI with time traveling debugger and DOM snapshots; headless run mode on CI with video recording by default; full browser DevTools to inspect the application's behavior; spying and stubbing of network calls; and many other advantages compared to existing solutions. Presented at Ministry of Testing Rio de Janeiro.
-
Cypress at ngBoston
Testing is hard. End-to-end testing is really hard. But maybe it is hard because our tools are not up to the task. What if we could redesign the testing experience from the ground up to be fast, useful and effective? In this presentation I will show Cypress - an open source end-to-end test runner designed from scratch to be useful to developers. Come to learn how testing can be ... a pleasure. AngularBoston 2018, video at https://youtu.be/wQfS3mCDVO0
-
Everything I know about writing quality software
In this presentation I will show all the tools I use to write software that does not break but keeps the users happy. Static types, exception monitoring, unit tests with snapshots, randomized testing, code and data coverage, code complexity metrics and awesome end to end testing tools - the list is long and keeps on growing! The techniques I plan to show are applicable to every framework and environment. Presented at BuzzJS 2018, video at https://youtu.be/1PMxLTfh6lo?t=1
-
Cypress at AngularNYC
Testing is hard. End to end testing is really hard. But maybe it is hard because our tools are not up to the task. What if we could redesign the testing experience from the ground up to be fast, useful and effective? Presented at AngularNYC meetup in May 2018, video at https://www.youtube.com/watch?v=wApmbgPGmqQ
-
Cypress at ReactNYC
Testing is hard. End to end testing is really hard. But maybe it is hard because our tools are not up to the task. What if we could redesign the testing experience from the ground up to be fast, useful and effective? Presented at ReactNYC meetup in May 2018
-
End to End Testing in the Future
Unit testing is hard and time consuming; and worse - the users and the customers do not care! They only want the features working in the production system, everything else is development overhead. If this is the case, how do we improve the web application quality? How do we catch the bugs early? How can we test the deployed system effectively? And finally, how do we get rid of Selenium? This presentation tries to answer many of these questions in a web framework agnostic way. Presented at WeAreDevs Congress 2018, video at https://www.youtube.com/watch?v=p38bIMC-YOU
-
Hyped about Hyperapp
What is the smallest and purest front end framework out there? Did someone say Elm? I said smallest! The answer is Hyperapp - a really tiny, Elm-inspired pure functional web framework that combines the best features of today's hottest frameworks. It has built-in state management, pure functions, virtual DOM and still is easy to learn in 30 minutes. Presented at Boston Code Camp in April 2018 and BostonJS meetup
-
Painless Testing for React Applications
Testing is hard. End to end testing is really hard. But maybe it is hard because our tools are not up to task. What if we could redesign the testing experience from the ground up to be fast, useful and effective? Let me show you how to quickly test a React application using Cypress.io - an open source modern test runner that replaces Selenium. Don't believe the hype - come see Cypress demo for yourself, and I guarantee you will start writing tests. Presented at ReactJS Boston meetup April 2018. Video at https://www.youtube.com/watch?v=lgurVvQsOTY
-
Modern JavaScript - NERDSummit 2018
Let us look at JavaScript - the language that runs the Internet. We will learn how new features are added to the language, how the modern syntax looks, and the main tools for testing, transpiling and bundling JavaScript applications. Anyone looking to start with JS or upgrade development skills will benefit from this presentation. Presented at NERD summit 2018.
-
It's not your parents' HTTP - NERD Summit
I will start with the history of HTTP, and how it changes from 0.9 to 1.0 and to 1.1. I will explain the performance benefit of HTTP/2, the state of support and a very interesting performance feature (Server Push). Then I will talk about real time systems that use Web Sockets for persistent data connection. Then I will talk about data synchronization solutions via in-browser database that can sync automatically. I will talk about offline support and instant web applications using ServiceWorker, and finally I will describe why HTTP/2 is going to be replaced by a protocol named QUIC based on UDP. Presented at NERDSummit 2018
-
Workers of the World, Unite!
WebWorkers have been very useful for performing computation-intensive tasks in parallel, preventing browser lockup. Recently a new beast has appeared: the ServiceWorker. I will show how to use both WebWorkers and a ServiceWorker to add new features to the web development: rendering HTML from data without blocking the main thread, supporting offline mode, computation-intensive tasks. ConFoo 2018
-
Testing Vue
Testing Vue web application using Cypress. End to end testing and integration testing of components. Presented at Vue.js Boston meetup on the last day of February 2018.
-
A Simple Node Checklist to Follow
Checklists have been known to reduce errors during air flights and surgeries. Why don't we use one for our JavaScript projects? I want my NPM module to be useful, robust, and well-documented. Here is my recipe for a module that everyone can rely on: a simple checklist. Rather than forcing everyone to do the same, the checklist only reminds me to do unit testing, publish smaller module, have good API examples, and lots of other useful things. ConFoo 2018
-
The Shape Of Testing Pyramid
Presentation for AssertJS 2018: testing pyramid, the difference in unit tests vs integration tests, using end to end testing tool to run unit tests for components, various types of diffing: snapshot testing, screenshot diffing, application behavior diffing. Video at https://www.youtube.com/watch?v=5FnalKRjpZk
-
Think Inside The Box
It used to be hard to actually run code in production. I needed to rent a rack server from a company, login into the machine, set it up, then periodically deploy new application version. Deploying often meant overriding the existing running application, taking a server offline. Long, cumbersome, and error prone. No wonder we did deploys once a month! Luckily there are 4 things that recently revolutionized the way I deploy and run code: Docker, Dokku, Kubernetes and Zeit Now.
-
Modern JavaScript
Let us look at JavaScript - the language that runs the Internet. We will learn how new features are added to the language, how the modern syntax looks, and the main tools for testing, transpiling and bundling JavaScript applications. Anyone looking to start with JS or upgrade development skills will benefit from this presentation. Presented at Boston Code Camp 2017.
-
The Future Belongs to You and Your JavaScript
Overview of modern JavaScript language and most commonly used tools. Browsers, servers, desktop and every place in between where JS can run. Code snippets and ServiceWorkers. Presented at Øredev 2017
-
Practical Universal Apps in Functional JavaScript
Writing solid code is hard. Writing portable code that can run on the server and in the browser is harder. Writing readable code that is easy to modify and extend might be impossible. Let us try achieve all three goals by writing JavaScript in functional style. JS is no Haskell, but can mimic a traditional functional language pretty well, as I will show in this presentation. Plus everything in the world can run JavaScript, so FP in JS knowledge applies very widely. Presented at Øredev 2017 video at https://vimeo.com/242030169
-
Modern Integration Testing for JavaScript Applications
Unit testing is hard and time consuming; and worse - the users and the customers do not care! They only want the features working in the production system, everything else is development overhead. If this is the case, how do we improve the web application quality? How do we catch the bugs early? How can we test the deployed system effectively? And finally, how do we get rid of Selenium? This presentation tries to answer many of these questions in a web framework agnostic way. BostonJS meetup. Video at https://www.youtube.com/watch?v=D20nX2zAypk
-
Snapshot Testing
Snapshot Testing is a recent technique in unit testing and automated testing in general that's been gaining some traction, thanks to a new excellent test runner called Jest. Gleb Bahmutov from Cypress.io will explain to us what snapshot testing is, and how to use his family of NPM modules snap-shot-* to go beyond static data. Presented at Atlanta JS Meetup, video at https://www.youtube.com/watch?v=MAKRJJ06Nw4
-
Effective E2E Testing with Cypress
The testing pyramid is a bad bad practice; it puts focus on unit tests, while your users really care about an end to end quality. For web developers, we are open sourcing a very powerful E2E tool called Cypress that is capable of giving your confidence that the app is going to work. Presented at AngularDevSummit 2017
-
Hello HTTP!
Let's walk through the history of HTTP, its original design goals and how they shape the modern Internet. We will look at the current standard, and what is coming tomorrow. We will also learn and refresh a whole bunch of acronyms: TCP, HTTP, RFC, IETF, UPD, QUIC. Every developer working or even using WWW will benefit from this presentation.
-
Shapes of Development
A geometric shape is simple to remember and visualize concept, familiar to any child. In software development we have a few concepts with associated shapes: agile is shown as a spiral curve, waterfall as, well, a waterfall, etc. In this presentation I will show the shapes that describe other modern development approaches and architectural styles.
-
Shhh, don't tell anyone but you are using HTTP/2!
I will walk through the history of HTTP, its original design goals and how they shape the modern Internet. We will look at at the current standard, and what is coming tomorrow. Through the presentation I will point at some security issues already found with HTTP/2 and its implementation.
-
It's not your parents' HTTP
The Internet of simple textual requests and responses is done. Finished. Obsolete. The modern web is a web of binary, persistent connections like WebSockets, WebRTC and HTTP/2. Presented at NDC Oslo 2017, video at https://www.youtube.com/watch?v=BhTbOtuSUzQ
-
Pure Magic: Functional Reactive Web Applications in 2017 and Beyond
There are a few web frameworks that are all the rage right now: React, VueJs, but which frameworks are functional AND reactive? Dr. Gleb Bahmutov will talk about functional reactive web applications you can write today, and why they are going to rock tomorrow. Presented at Maine.JS meetup in May of 2017
-
Web app quality beyond testing - CycleConf 2017
What makes a framework great? How do you have others give it a try? How do you make sure the web application runs correctly? What is a brass ball valve? Video at https://vimeo.com/album/4578937/video/216829554
-
Self-improving software - NodeWeek
Every JavaScript project requires 3rd party modules. As soon as you depend on specific versions, your module falls behind. I will show how to keep your software up to date without any effort (as long as there are some tests). Everything will be automated and reliable; it is like bringing an army of robots to help you.
-
Self-improving software - ConFoo CA 2017
Every JavaScript project requires 3rd party modules. As soon as you depend on specific versions, your module falls behind. I will show how to keep your software up to date without any effort (as long as there are some tests). Everything will be automated and reliable; it is like bringing an army of robots to help you.
-
Remove the boilerplate - ConFoo CA 2017
In this talk I will show how to remove lots and lots of unnecessary code from your application. Counter variables, wrapper functions, callbacks - they can all be removed using utility libraries or even built-in JavaScript ES5 language features. In each instance there will be a lot less code, but it will be more robust, manageable and simpler to reason about and test. Presented at ConFoo.CA in March 2017
-
Snapshot Testing the Hard Way
Testing is hard and does not pay. Snapshot testing is a way to increase the efficiency of your unit tests while removing a lot of boilerplate code. Recently Jest and Ava testing framework added this feature. I have written a framework-agnostic snapshot testing library and would like to share techniques and design decisions that went into this library.
-
Writing Software That Works
How to write software that works now and will keep working in the future. Plus career advice! Presented as a guest lecture at MIT 6.148 class, January 20th 2017. Developer value, JavaScript modules, semver, linting, unit testing, e2e testing. Video at https://www.youtube.com/watch?v=MHNB6CGENKo
-
Browser is the new server - NodeFest Tokyo
The line between the server and the modern browser is blurry. Transpiling code, rendering static markup, smart caching were traditionally done on the server. These features made the jump to the browser by using ServiceWorkers.
-
Browser is the new server - NodeConf EU
The line between the server and the modern browser is blurry. Transpiling code, rendering static markup, smart caching were traditionally done on the server. These features made the jump to the browser by using ServiceWorkers. Video at https://www.youtube.com/watch?v=5zOaN_FYXwk
-
Secure your Angular Applications
What do Chrome extensions written in Angular and secure websites have in common? They take Content Security Policy seriously! In this presentation I will show how to secure your web application against cross-site scripting attacks and insecure 3rd party code.
-
Fun* JavaScript Workshop
The principles and basics of functional programming in JavaScript using small coding problems. Pure functions, partial application, composition, iteration, lexical scope, Ramda library.
-
Cycle.js: Get in the Loop
Cycle.js - functional reactive framework for pure web apps. Presented at FrontEndCamp at United Nations NYC July 2016. Links and additional resources at https://glebbahmutov.com/blog/cyclejs-frontendcamp/
-
Which JavaScript framework should I use next? - BuzzJS NYC 2016
Should I learn and use Angular 1, React, Angular 2, Ember or something else? What are the common features they all share? How are they different? Are there "better" frameworks that will be popular next year? I will show a couple of new approaches that should be part of any future-proof framework: reactive streams for managing the data flow, virtual DOM abstractions for speed, testability and performance tools built right into the framework. The presentation might be controversial, but the struggle to pick "the next best thing" is very real. Video at https://www.youtube.com/watch?v=ji8hqDi2BnA
-
From procedural to reactive JavaScript with stops - O'Reilly OSCON
How do we convince / train developers used to imperative programming style to switch to functional or even reactive programming? I show the same example implemented in multiple styles to highlight the advantages one would get by going from imperative to object-oriented, functional, lazy evaluation, promise-based, event emitters, and finally reactive approach. The short examples are in JavaScript - the most widely used functional language today.
-
MVC to FRP
Transition from the traditional Model-View-Controller application to Functional-Reactive-Programming. Presented at CycleConf 2016. Video at https://www.youtube.com/watch?v=-PCq4pXaDZw and all links are in blog post https://glebbahmutov.com/blog/cycle-conf/
-
Secure the front end from Node server - Boston Code Camp 25
This presentation will show how to lock down the front end JavaScript code using Content-Security-Policy. I will also show how to prevent sensitive files from being committed to your repos or NPM registry. Presented at Boston Code Camp 25 on April 2nd 2016.
-
Remove the boilerplate - Boston Code Camp 25
How to remove unnecessary code from your code, including asynchronous code and unit tests. Presented at Boston Code Camp 25 on April 2nd 2016
-
Workers of the world, unite!
ServiceWorkers for faster web application boot up. Instant web applications, self-rewriting apps, profiling, ES2015 and modern browsers. Presented at the Web Performance NYC meetup. Video https://youtu.be/4axZ3D75Llg
-
Remove the boilerplate - NationJS
How to remove unnecessary code from your code, including asynchronous code and unit tests. Presented at NationJS Node day 2016 in Washington DC.
-
Unit testing AngularJS - ConFoo.ca
Testing Angular code requires too much boilerplate. In this presentation I will show ng-describe - a BDD helper that removes all extra code and allows to start unit testing in seconds.
-
NodeJS for secure websites
This presentation will show how to lock down the front end JavaScript code using Content-Security-Policy. I will also show how to prevent sensitive files from being committed to your repos or NPM registry
-
Journey from imperative to reactive JavaScript with stops - Boston Code Camp 24
How do we convince / train developers used to imperative programming style to switch to functional or even reactive programming? I show the same example implemented in multiple styles to highlight the advantages one would get by going from imperative to object-oriented, functional, lazy evaluation, promise-based, event emitters, and finally reactive approach. The short examples are in JavaScript - the most widely used functional language today.
-
Explain with examples, without writing any
Humans learn best by example; good technical docs use lots of them. Yet all modern documentation tools (think jsdoc) making writing correct examples and maintaining them a chore. There is no tool support for syntax highlighting, or even guarantee that an example is correct or up to date. On the other hand, solid software projects have lots of well tested, up to date examples. We call them unit tests! In this presentation I will show how to take the unit tests and transform into syntax-agnostic human-friendly examples to be plugged into your docs.
-
Обзор будущих технологий тестирования / Testing technologies of the future
В этом докладе я покажу самые последнии идеи для достижения надежного программного обеспечения для веб: от data-coverage (вместо code-coverage) до тестирования недоступого кода (например, внутри private JavaScript closures), от минимизации boilerplate до тестирования веб-приложений без помощи браузеров; эти решения помогут быстро и дешево достичь высокого уровня качества.
-
Turn the performance knob to 11
Once your Angular application has the features you need, the next step is usually focused on improving its performance, such as the initial load time and responsiveness to user’s commands. The application has to execute quickly in order to be useful. Is the Angular framework fast or slow? I argue that it is very fast, but requires you to know how to measure and optimize the right bottlenecks.
-
Remove the boilerplate
How to remove unnecessary code from your code, including asynchronous code and unit tests. Presented at NodeJS Italy in 2015
-
MIT Career Fair
A presentation for prospective candidate who are interested in joining Kensho. What we do, how we do it, why someone should join us, and how to ace our interview.
-
Unit testing AngularJS - Angular Remote Conf
Testing Angular code requires too much boilerplate. In this presentation I will show ng-describe - a BDD helper that removes all extra code and allows to start unit testing in seconds. Then I will show ng-dice - a combination of dependency injection and code extraction for testing Angular taking advantage of Node require hooks.
-
Effective public speaking
A few tips for organizing and delivering an effective presentation by carefully preparing the content
-
Bend the JS rules in Angular application
Bend the JavaScript rules for powerful Angular applications: access the controller logic from the browser console, mock on the fly, load app from Node, unit test private functions. Presented at ManhattanJS meetup.
-
Unit testing AngularJS
Testing Angular code requires too much boilerplate. In this presentation I will show ng-describe - a BDD helper that removes all extra code and allows to start unit testing in seconds. Presented at AngularNYC meetup in November 2015, video at https://www.youtube.com/watch?v=9DMuLsWzqwg
-
Self-improving software FrontEnd Camp
Any JavaScript project requires 3rd party modules. As soon as you depend on specific versions, your module falls behind. I will show how to keep your software up to date without any effort (as long as there are some tests). You can automatically upgrade dependencies for an individual project, a collection of projects. You can even see the anonymous version upgrade results across the public projects around the world to judge if a particular update is likely to succeed. What about projects that depend on your software? Before releasing a new version, you can test some or all of your dependencies against the new code.
-
Journey from procedural to reactive JavaScript with stops - FrontEnd Camp
How do we convince / train developers used to imperative programming style to switch to functional or even reactive programming? I show the same example implemented in multiple styles to highlight the advantages one would get by going from imperative to object-oriented, functional, lazy evaluation, promise-based, event emitters, and finally reactive approach. The short examples are in JavaScript - the most widely used functional language today.
-
Self-improving software NYC NodeJS meetup
Any JavaScript project requires 3rd party modules. As soon as you depend on specific versions, your module falls behind. I will show how to keep your software up to date without any effort (as long as there are some tests). You can automatically upgrade dependencies for an individual project, a collection of projects. You can even see the anonymous version upgrade results across the public projects around the world to judge if a particular update is likely to succeed. What about projects that depend on your software? Before releasing a new version, you can test some or all of your dependencies against the new code.
-
web application profiling using code snippets
Chrome DevTools code snippets became my favorite tool when investigating performance bottlenecks in web applications. A JavaScript fragment can be stored as a named snippet in the "Sources" DevTools panel and executed in the current page's context, just as if it were a code executed in the browser's console.
-
Self-improving software
Any JavaScript project requires 3rd party modules. As soon as you depend on specific versions, your module falls behind. I will show how to keep your software up to date without any effort (as long as there are some tests). You can automatically upgrade dependencies for an individual project, a collection of projects. You can even see the anonymous version upgrade results across the public projects around the world to judge if a particular update is likely to succeed. What about projects that depend on your software? Before releasing a new version, you can test some or all of your dependencies against the new code.
-
An orchestra of rockstars
Hiring, training and graduation approaches that work for us at Kensho (data analysis and machine intelligence company in Boston and NYC)
-
Journey from procedural to reactive JavaScript with stops - ScotlandJS
How do we convince / train developers used to imperative programming style to switch to functional or even reactive programming? I show the same example implemented in multiple styles to highlight the advantages one would get by going from imperative to object-oriented, functional, lazy evaluation, promise-based, event emitters, and finally reactive approach. The short examples are in JavaScript - the most widely used functional language today.
-
Run digest cycle in web worker
An experiment in offloading the Angular dirty checking and model update step to a separate browser thread. ng-conf 2015, Salt Lake City, Utah. Video at http://youtu.be/lceLw8ROUP8?list=PLOETEcp3DkCoNnlhE-7fovYvqwVPrRiY7
-
Journey from procedural to reactive JavaScript with stops - MountainWest JS 2015
How do we convince / train developers used to imperative programming style to switch to functional or even reactive programming? I show the same example implemented in multiple styles to highlight the advantages one would get by going from imperative to object-oriented, functional, lazy evaluation, promise-based, event emitters, and finally reactive approach. The short examples are in JavaScript - the most widely used functional language today.
-
Journey from procedural to reactive JavaScript with stops
How do we convince / train developers used to imperative programming style to switch to functional or even reactive programming? I show the same example implemented in multiple styles to highlight the advantages one would get by going from imperative to object-oriented, functional, lazy evaluation, promise-based, event emitters, and finally reactive approach. The short examples are in JavaScript - the most widely used functional language today.
-
Performance Profiling Using Chrome Code Snippets
Chrome DevTools code snippets became my favorite tool when investigating performance bottlenecks in web applications. A JavaScript fragment can be stored as a named snippet in the "Sources" DevTools panel and executed in the current page's context, just as if it were a code executed in the browser's console.
-
AngularJs Performance
profiling and improving AngularJs application performance using code snippets, working in batches, offloading work, on-demand computation, memory preallocation and smart DOM updates.