Ruby Video
Refactoring

Lightning Talks Saturday

#developer-tools
#refactoring
#ruby-on-rails
#sinatra
#testing
#web-development
#ruby

Lightning Talks Saturday

by Marta Paciorkowska, Norbert Wójtowicz, Piotrek Zientara, Marcin Stecki, Aleksander Dąbrowski, Marcin Grzywaczewski, Mateusz Lenik, Arne Brasseur, Michal Papis, Thilo Utke, and Mateusz Kubiczek

The video titled "Lightning Talks Saturday" features a series of short presentations by various speakers during the wroc_love.rb 2014 event. The session primarily involves technical discussions centered around Ruby, software engineering practices, and various tools used in development.

Key Points Discussed:

- Chef Browser Introduction by Marta Paciorkowska:

- Overview of Chef, a configuration management tool, and its common commands like 'knife'.

- Presentation of Chef Browser, a read-only web UI for Chef that simplifies data navigation.

- Features include user authentication, easily navigable attributes, live filtering, and planned support for handling cookbooks.

  • Refactoring in Ruby by Norbert Wójtowicz:

    • Discussion on the challenges of code maintenance in evolving projects.
    • Introduction of the MethodStruct gem for efficient code refactoring, promoting the single responsibility principle.

  • A Philosophical Inquiry by Beatrix Zientara:

    • Posed a philosophical question regarding the existence of Ruby objects and invited audience participation through a survey.

  • Ping Pong Coding Concept by Michal Grab:

    • Explains the idea of a collaborative coding platform inspired by DHH’s coding philosophy, allowing developers to share their ideas and get feedback.

  • Defending Rails by Alex Dąbrowski:

    • Advocated for Ruby on Rails, emphasizing its simplicity and effectiveness while cautioning against over-engineering applications.

  • React.js and Hexagonal Architecture by Marcin Grzywaczewski:

    • Addressed integration challenges between React.js and Hexagonal JS for building decoupled systems.

  • Randomness in Ruby by Thilo Utke:

    • Highlighted the shortcomings of Ruby's Random class for production use and stressed the importance of using SecureRandom instead.

  • Ruby Syntax Tips by Mateusz Kubiczek:

    • Shared lesser-known Ruby features, including the flip-flop operator, block-local variables, and simplified regex handling.

  • RVM Updates by Michael Papis:

    • Shared updates about RVM development and its financial support, encouraging continued community contributions.

  • Wi-Fi Challenges and Solutions by Matt:

    • Addressed technical issues related to event Wi-Fi setup and offered tips for reliable connections.

Overall, the session is a fast-paced exchange of ideas and presentations, showcasing innovative tools and best practices in Ruby development, encouraging audience engagement, and emphasizing collaboration in coding.

00:00:13.840 Hi! So, who among you has used Chef? Yay! My talk will make sense, so anyway.
00:00:20.080 I'm Marta Paciorkowska, a junior software engineer at CEO of Coins. You know the drill: Twitter, GitHub.
00:00:26.400 I'm here to talk about Chef Browser.
00:00:32.320 Chef Browser is a very simple tool designed to enhance your everyday work with Chef. If you use Chef, you probably also use Knife.
00:00:39.600 If you frequently use commands like `knife show` and `knife list`, you might have noticed that finding certain types of data can be cumbersome.
00:00:45.280 For example, when you realize how nested some of the JSON attributes are, it might not be so easy to make sense of them.
00:00:51.680 You may find yourself lost regarding your exact location within the data. Additionally, since it's a console tool, sometimes you may want a full-fledged app for that.
00:01:06.960 That's where Chef Browser comes in. It's a read-only Chef web UI, which I will showcase today.
00:01:12.240 Chef Browser is made in Ruby and Sinatra, and it is completely open source. If you like it, you can contribute to it.
00:01:19.759 Now, let me show you a live demo of how Chef Browser looks.
00:01:25.600 All I have to do is download it from GitHub, set it up, and Chef Browser allows you to secure access to your data via a login screen.
00:01:31.200 All users that have access to this data come from the Knife user list.
00:01:38.479 So, as a Knife user, I type in my super secret password and I'm in.
00:01:44.799 The first thing I see is a list of attributes, which includes all the resources available on my Chef server.
00:01:51.439 These are divided into environments, roles, and data bags. You can also view data bag items.
00:01:58.079 When I click on any of those nodes, environments, or roles, I can see all the attributes of a given resource.
00:02:04.640 The views of the attributes are specific to the resource, but the basics are the same. First, you see general information about the resource.
00:02:12.800 When it comes to nodes, you can see FQDN, IP addresses, the environment this node is running in, and all associated tags.
00:02:19.280 You can click on these tags and view the node's run list.
00:02:24.480 Below that, you can see a handy list of JSON attributes, which I present in a flat structure as a JSON path.
00:02:30.480 Regardless of how deeply nested you are, you know exactly where you are. Moreover, all the attributes are divided into different categories.
00:02:36.640 As you can see, they fall under default, normal, override, and automatic categories based on their priority.
00:02:44.640 This makes it very easy to navigate through the data.
00:02:52.480 For example, if you want to know what Ohai is responsible for, you just click on the automatic tab.
00:02:59.280 Another cool feature of Chef Browser is live filtering of all the attributes.
00:03:05.280 If you're unsure of what you're looking for, you can simply experiment by typing keywords.
00:03:13.440 For instance, if I type 'ruby', I can see everything that matches that term.
00:03:20.879 You can also search for nested data by adding a dot to your query, such as looking for versions.
00:03:26.879 And there you go!
00:03:31.920 Chef Browser also mimics a Knife search. For example, if I want to look for nodes named 'production' or 'batch', I can enter that in the search field.
00:03:38.720 Just press enter, and here are all the nodes named 'batch'.
00:03:43.840 If I search for specific information, for example, a person who keeps forgetting their MySQL password, I can simply open my settings file.
00:03:49.920 It’s a simple file that looks more or less like this.
00:03:55.760 In this file, I can define my saved searches.
00:04:02.160 Then, when I run Chef Browser, those saved searches will appear.
00:04:07.840 For instance, I can just click here, and voilà! There it is.
00:04:26.960 Environments look a little different. Besides a list of attributes, you can also easily find all the nodes connected to a specific environment.
00:04:34.479 This is very useful, especially for roles. You can see the run list on the role's dashboard.
00:04:41.240 Everything in the UI is clickable, allowing for easy navigation.
00:04:47.680 In the future, we are planning to implement support for handling cookbooks, so you'll be able to view recipes and the contents of every file in a cookbook.
00:05:26.960 Uh, Florian, are you still here?
00:05:42.080 Ready, set...
00:05:49.759 Ready, set, go! You're cheating! I'm cheating! Hi, Norbert!
00:05:55.600 I want to tell you about my favorite Ruby refactoring tool. We're going to pull some code off of GitHub.
00:06:01.759 But we're not going to analyze the code; instead, we are interested in code shape.
00:06:07.680 So, we have a class. Since it's a real project, it inherits from multiple other classes and has a method that does one thing.
00:06:14.960 It is a good method. However, as requirements evolve, we start incorporating branching.
00:06:20.560 Then there are assertions we need to do ahead of time.
00:06:26.400 We begin including other code that does things not necessarily related to that method.
00:06:32.800 This other code starts throwing exceptions, and it becomes overwhelming to handle all these errors.
00:06:39.520 Over time, these methods evolve into humongous beasts that we cannot effectively manage.
00:06:45.840 Eventually, someone suggests adding comments to help make sense of it all.
00:06:52.160 This may help momentarily, but the real solution is to revert that commit quickly.
00:06:57.199 Then we need to perform the next best thing, which is to extract the method.
00:07:03.840 It turns out that usually, when you extract, you create even more blocks, which is beneficial.
00:07:11.360 However, this is where our refactoring tends to stop, and that’s a problem.
00:07:16.800 Because this class evolves over time and is doing more than it should.
00:07:22.800 In reality, it looks much messier when you open it in an editor.
00:07:27.840 This complicates troubleshooting any bugs that arise.
00:07:34.000 This is where the concept of service object extraction comes in.
00:07:40.319 We need to pull out all the helper methods into a separate class, completely isolating it.
00:07:46.800 The original controller will only call this service object.
00:07:52.960 The tool I'm referring to is a gem called MethodStruct, which is about 10 or 15 lines of code.
00:07:59.759 It codifies this process, effectively removing boilerplate.
00:08:05.199 It requires you to do three things: figure out a name for the action you want to perform, identify dependencies, and implement the method call.
00:08:10.720 Since it’s a separate class, you can add all these helper methods you’d ordinarily do in plain Ruby.
00:08:16.879 You can call them either via a class method or instantiate them later.
00:08:23.680 Calling by default works seamlessly, as it functions similarly to Procs and Lambdas.
00:08:30.639 However, it also allows passing custom method names, which can be great.
00:08:36.000 For instance, if using Delay Job, it can assume the method is going to be called 'perform'.
00:08:41.599 You can actually define a separate method.
00:08:46.720 While it’s a simple concept, what we found is once we started using it in production, there were numerous benefits.
00:08:53.200 First, it compels you to label the action you're performing accurately.
00:09:00.240 For instance, the email invite for user registration is no longer just a callback in a model.
00:09:06.000 It becomes part of the business of the user registration action.
00:09:11.920 Not only must you name the methods in a way that reflects their purpose, but you also need to identify possible dependencies.
00:09:16.959 Moreover, all the extracted methods will help prevent future dependencies on what you originally refactored.
00:09:22.000 This prevents undesired dependencies on private APIs.
00:09:27.120 Following the principle of single responsibility is paramount.
00:09:32.160 Overall, this approach encourages composition over inheritance, leading to much more isolated tests.
00:09:39.600 That’s me! That’s MethodStruct, a very simple gem.
00:09:44.320 Since I have about 30 seconds left, I want to mention that ImmutableStruct is also fantastic. Thank you!
00:09:51.680 Given the circumstances, I need to introduce two new rules for the lightning talks.
00:09:57.360 Rule number one: less than 100 words per minute, which you definitely broke.
00:10:03.120 The second rule: you need to mention the word 'Java' at least once.
00:10:10.000 Ready, set, yeah, try it out! Hello!
00:10:15.760 Hi there, my name is Beatrix Zientara.
00:10:20.000 I'm a developer at Rebased. I work with Thomas and Piotr, who will be giving a presentation today on testing.
00:10:26.480 I have only one question, so I won't take up the whole five minutes.
00:10:31.680 Maybe I'll speak a little longer, but I want to ask you one philosophical question: do Ruby objects exist?
00:10:45.200 You can fill in a survey; I know you may perceive this question as stupid.
00:10:50.240 If that’s the case, please explain why you perceive it that way.
00:10:56.880 Your feedback will greatly help me, as I'll have a presentation on this topic in Warsaw next week at the Ruby Users Group.
00:11:04.079 I would be very grateful if you fill in the survey. That’s everything. Thank you very much!
00:11:12.399 Actually, you fulfilled the first rule, but not the second, so you won't be considered for the prize draw.
00:11:16.400 The survey is available on Facebook, it’s on our page.
00:11:21.360 Thank you!
00:11:24.000 What is your thing?
00:11:25.000 Ready, set...
00:11:30.000 Because it's Linux.
00:11:33.000 Ready, set, go!
00:11:40.000 Michael, Michael Grab! Hello. Yes, thank you!
00:11:45.680 So, where did ping pong come from?
00:11:51.280 There was a post by the guys from Groupon who shared some insights about things we discussed yesterday.
00:11:56.720 One guy mentioned that someone would soon know about it, pointing out some missing parts of the race, and wrote an insightful article.
00:12:06.119 And what happened was that DHH participated in this conversation on Hacker News, sharing very honest views.
00:12:14.000 He expressed his disinterest in abstract discussions but emphasized a desire to code collaboratively.
00:12:20.000 This inspired me to create a simple application for DHH, where you can submit your ideas with your code base.
00:12:26.679 DHH would then respond with his version, enabling a ping pong of code.
00:12:34.960 The plan is to select the five best entries submitted through this platform, which DHH agreed to participate in.
00:12:43.200 You can sign in via GitHub, and please provide your email for newsletters.
00:12:51.679 After a week, we'll send the selected entries to DHH and ensure he keeps his promise.
00:12:58.399 Thank you!
00:13:01.920 You didn’t mention Java! The entire thing would not have happened if the guys from Groupon had written their code in Java.
00:13:05.839 Okay.
00:13:08.720 Ready?
00:13:13.680 Set!
00:13:14.000 Thank you!
00:13:19.000 Ready, set, go! Java is cool!
00:13:24.120 Thank you, that's done! Ruby on Rails rocks!
00:13:29.280 My name is Alex, and I’m here as a devil's advocate because all day I hear Rails is not good.
00:13:35.280 I want to remind you that Rails is cool.
00:13:41.680 Who thinks that Rails is not cool?
00:13:43.000 Okay, how about Rails is cool? Everyone loves Rails!
00:13:50.000 What about REST?
00:13:51.000 Okay, let's see.
00:13:55.200 So, back in 2006-2008, Rails was brand new.
00:13:57.040 We could create a blog in 15 minutes, a shop in just a few days. It was fantastic!
00:14:04.240 And here we are, still able to do that now.
00:14:11.160 Most Rails applications don't need a separate persistence layer, and many are actually quite simple.
00:14:19.760 It’s important to remember not to over-engineer your applications.
00:14:26.000 By the way, what are your alternatives to Rails?
00:14:32.400 Who here uses Sinatra in production? Wow, more people than I expected!
00:14:39.680 It’s interesting because there is a phenomenon where every advanced Sinatra application eventually gets rewritten in Rails.
00:14:44.960 That, however, is not necessarily true.
00:14:51.040 If your application is advanced enough, you likely won’t need to rewrite it.
00:14:57.520 Rails is undoubtedly cool! Just follow a few guidelines and you'll be just fine.
00:15:04.320 Avoid using observers and things will be okay.
00:15:10.920 You might also want to reconsider overly complex filters and helpers.
00:15:17.040 In short, use Rails well, and you can avoid common pitfalls.
00:15:23.440 Remember the reasons why we choose Ruby and Rails.
00:15:30.720 Many of you transitioned from PHP because Ruby allows for cleaner code.
00:15:37.440 Furthermore, others came from Java and we know that excessive abstraction is too complex.
00:15:43.520 Let’s stick to Ruby's simplicity.
00:15:50.000 Thank you!
00:15:56.080 Thanks for mentioning Java twice!
00:15:59.040 Come on!
00:16:00.000 Ready, steady...
00:16:05.760 Whoa! It’s Linux and it worked!
00:16:11.840 That's an improvement from last year!
00:16:16.160 Hello! I would like to talk about React.js and Hexagonal JS. Has anyone developed with React.js before?
00:16:39.840 Have any of you worked with Hexagonal JS before?
00:16:44.240 We need to integrate both concepts effectively.
00:16:49.680 In our company, we use Hexagonal JS to create decoupled systems.
00:16:54.720 This involves use case adapters and graphical interfaces.
00:17:00.320 We need to glue everything together while incorporating aspect-oriented programming.
00:17:05.680 So why React?
00:17:12.160 Does anyone need an explanation of how awesome it is?
00:17:16.960 Here's how a component in React looks. It includes a simple counter concept.
00:17:24.800 We need to combine it with our use case, which accomplishes the same objectives.
00:17:31.120 The challenges arise when we try to glue it together.
00:17:38.560 After building it, we need to confirm that everything works.
00:17:43.520 Oh no, it probably won’t!
00:17:49.760 However, here's a tip: if you run into a problem where the method only activates after invoking it a second time, force an update.
00:17:56.000 When gluing components together with aspect programming, we must apply the right methods at the appropriate times.
00:18:02.080 Thank you!
00:18:07.360 Ready? Okay, set, go!
00:18:08.960 So, let's discuss randomness in Ruby.
00:18:14.080 The Random class isn’t ideal for production use.
00:18:20.800 Most developers think otherwise, but I have seen instances where this class has been utilized.
00:18:26.000 If you're employing it, here are the reasons you should reconsider.
00:18:32.000 Do you truly understand whether a series of outputs is random?
00:18:40.000 With longer samples, it remains elusive.
00:18:46.000 Ruby's random number generator, which utilizes the Mersenne Twister library, initializes with a 32-bit integer.
00:18:52.000 It generates a state as an array of 624 integers used in a shift register.
00:18:58.720 The output generation is reversible, which facilitates predictions.
00:19:05.120 To disrupt predictability, gather 624 outputs.
00:19:11.080 While it may seem challenging to reverse the equations, they can be simplified.
00:19:17.760 I will demonstrate with Python, as it's simpler to reset the generator's state in that language.
00:19:23.920 The goal here is guessing a few consecutive numbers, which are 64-bit integers.
00:19:29.760 The demonstration uses two outputs concatenated together.
00:19:37.520 Once you've acquired those outputs, you can predict the generator's future numbers.
00:19:45.200 As a result of understanding its state, I successfully predicted the outputs.
00:19:52.240 In conclusion, avoid predictable random number generators, especially those based on current time.
00:20:00.000 Also, avoid leaking random outputs, and remember to use SecureRandom for serious scenarios.
00:20:06.400 Thank you.
00:20:11.240 Ready? Set, go!
00:20:17.360 Nobody knows Ruby well, but these are simple things.
00:20:22.880 I think many of you will still learn something advantageous.
00:20:28.000 Firstly, I just learned this yesterday in IRB: you can retrieve the last evaluated value using an underscore.
00:20:34.000 Now, onto some obscure Ruby syntax: the flip-flop operator.
00:20:40.000 Watch me live code! I have a list of strings to demonstrate this.
00:20:47.248 The dot-dot here signifies a flip-flop operation, acting as a switch.
00:20:54.560 The first expression turns the switch on, while the second turns it back off.
00:21:00.960 Isn't that fascinating? Can Java do this? I don't think so.
00:21:08.160 Next, let's talk about block-local variables.
00:21:12.160 We know that if the variable already exists, it will get redefined inside the block.
00:21:18.080 However, you can scope it properly by using a semicolon.
00:21:23.680 That’s pretty neat!
00:21:29.840 Now about complicated regular expressions: explaining them can be challenging.
00:21:34.880 However, appending 'x' to the end allows for white space and comments.
00:21:41.120 This greatly simplifies complex regex explanations.
00:21:47.400 If you have a bit more code on this slide, you can see how clean it can be.
00:21:52.240 Unicode literals in strings? In Ruby 1.8, these were only character arrays.
00:21:56.920 But in Ruby 1.9, they're now treated as character arrays or code points.
00:22:02.760 This allows you to easily insert specific Unicode characters using hexadecimal.
00:22:08.000 We now have enumerators to loop over each character and perform operations, such as drop and select.
00:22:14.160 Want to define ranges in regex for those characters? You can do it!
00:22:21.920 Let’s review how we can use those Unicode code point ranges to scan strings.
00:22:29.040 Now, we can extract all Chinese characters without any problem.
00:22:34.800 Remember, with integers, you can convert them to hexadecimal using `to_s`.
00:22:41.040 And with method object calls, the responds_to method can utilize procs.
00:22:48.000 This allows enums to easily combine using simple regex.
00:22:55.040 On the command line, Ruby can function like awk.
00:23:02.160 Using the standard input, Ruby can read every line, and using '-n' assigns the line to`$_.`
00:23:08.960 You can output results by using `p` at the end.
00:23:14.560 You can even designate delimiters with `-F` for easy processing.
00:23:20.000 Time's up, but I hope you learned something valuable about Ruby!
00:23:27.600 Thank you very much!
00:23:31.679 I’ll mention Java most often!
00:23:34.760 Hello! Ready?
00:23:40.080 Thank you! My name is Michael Papis.
00:23:46.569 I run RVM, but I struggled to mention Java.
00:23:51.360 Some time ago, I faced issues with engineering.
00:23:55.920 They stopped paying me for my work on RVM.
00:24:01.200 Thanks to your contributions, we raised $51,000!
00:24:08.160 Big thanks to all who supported this project. It allows me to work on RVM until the end of the year.
00:24:12.960 Currently, we have RVM 1.25, and I probably won't add any new features.
00:24:19.920 Please adjust to this version as it will be the last one.
00:24:27.200 If any problems arise, feel free to report them!
00:24:33.040 As long as RVM 2 is not released, I will fix issues for RVM 1.
00:24:39.520 I had some downtime while troubleshooting RVM 1, but I've also played Warzone 2100.
00:24:46.400 It's an open source game available for Windows, OS X, and Linux.
00:24:55.200 Give it a try! If you have any questions, I’ll be at the party, so feel free to chat.
00:25:00.800 Thank you!
00:25:06.240 So who's left? Is anyone else here?
00:25:09.560 Okay, ready, go!
00:25:12.640 Thank you! Well, I heard some laughter.
00:25:20.000 It's hard to solve the problems with Wi-Fi. Kudos to the hosting team!
00:25:27.720 They did a commendable job!
00:25:32.160 They provided proper hardware that actually works with Java.
00:25:38.160 They also did not implement a captive portal like they did last year.
00:25:44.240 This greatly reduced issues attendees faced.
00:25:49.120 With the captive portal, everyone was blocked.
00:25:53.120 Another issue arose with the subnet mask. It can only handle 120 users.
00:26:00.000 There's a limit on the number of connections on the network.
00:26:05.920 It’s important to keep this in mind.
00:26:12.240 If you really want to provide fast and reliable Wi-Fi, consider using a 5GHz network.
00:26:18.560 That’s still empty and underutilized.
00:26:21.680 However, it's crucial to have enough access points to serve 300 people adequately.
00:26:32.000 Additionally, I’ll touch on smaller tips, such as why mounting Wi-Fi under your seat is effective.
00:26:38.399 You can read my blog post about it.
00:26:43.440 Thank you!
00:26:49.920 Hello! I’m Matt.
00:26:56.000 I run a consulting service called The Software House.
00:27:01.320 Today, I played this game and was very close to winning.
00:27:06.720 Besides playing games, we build a lot of fun stuff to get paid.
00:27:12.000 We usually work with foreign clients, so getting paid in several currencies can get tricky.
00:27:19.680 Let’s talk about how to receive payments without getting ripped off!
00:27:25.440 Clients often prefer PayPal, but my experience with it may vary.
00:27:30.000 There are usually hefty commissions involved, around 3 to 4 percent.
00:27:35.760 They also often make you convert currencies to withdraw funds.
00:27:41.360 That’s where you might end up losing a lot of money.
00:27:46.800 Avoid receiving wires in euros to a Polish złoty account!
00:27:51.120 We lost a considerable amount of money due to previous mishaps.
00:27:55.680 The best option is to set up a dedicated currency account for wire transfers.
00:28:01.600 Using online exchange services can help minimize costs.
00:28:06.320 Wire transfers often range between $20 to $50 and are pretty fast.
00:28:12.239 Alternatively, you could use Authorized.Net or another card processor to handle credit card payments.
00:28:17.920 This may incur lower fees of about 2 to 2.5 percent.
00:28:23.680 Clients appreciate using credit cards, but setting it up can be a hassle.
00:28:29.920 Especially if it involves quite a bit of paperwork.
00:28:34.000 Furthermore, once set up, you still need to handle currency conversion.
00:28:39.240 Finally,
00:28:49.680 if you frequently pay for services like GitHub or Jira, consider using cards in euros.
00:28:55.760 Thank you!
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