Questions about Ruby, dynamic, reflective, general-purpose object-oriented programming language that combines syntax inspired by Perl with Smalltalk-like features.
3
votes
1answer
93 views
Testing: why expect_any_instance_of is considered a design smell?
In this question, I'll use a ruby example, but I think it is a general question.
According to the most popular Ruby's test framework (RSpec), mocking any instance of a class (allow_any_instance_of) ...
-1
votes
1answer
68 views
Can I use python 3.5.2 on my machine for development if the client is 3.4?
Here is the situation, I wish to use the last programming language of ruby, python and some more on my development machine, but the server where it will be is not last version of that programming ...
1
vote
1answer
80 views
API oriented web app for both public and private consumptions in Ruby
In traditional Rail app, we need to deal with controller/model/action and has a view that generate HTML output. Now
There are many JS framework like backbone/react that allow us to code client side ...
0
votes
0answers
63 views
Conceptual similarity between Ruby's and JavaScript's inheritance models
To clear some potential confusion, let me start with the following statements
As far as I understand, inheritance is mostly about dynamic dispatch.
I understand how virtual pointer table based ...
10
votes
3answers
389 views
Why did Ruby creators had to use the concept of Symbols?
So, why did Ruby creators had to use the concept of symbols in the language?
I ask from the perspective of a non-ruby programmer trying to understand it. I've learned lots of other languages and ...
2
votes
2answers
178 views
When is it ok to instantiate all of my objects upfront?
I am currently working with a contractor who's code instantiates a large number of objects upfront at the start of the application. This application is written in ruby, but I wonder how something ...
0
votes
1answer
68 views
database architecture for ecommerce app
I’m creating an app that allows users to post, sell, and purchase items. Every item has a count integer attribute that is set by the initial user and which is reduced by n with each purchase. When ...
0
votes
0answers
75 views
Using Ruby ORM vs DB querying
If one were to set up an API in Sinatra connecting to MongoDB, is it absolutely necessary (or even a "best practise") to define models and use Mongoid (for example) to run DB operations such as User....
0
votes
0answers
16 views
RubyMotion deployments
I would like to start an application for iOS and Android and I'm considering the option of using RubyMotion for that. I know that you can write Ruby and then deploy to the desired platform.
After ...
0
votes
1answer
76 views
Name of a symbol in ruby
I'm very new to ruby. I have to code in ruby at work and a coworker gave me some tests he wrote in ruby. I have some difficulties to understand a line he wrote.
We have a class like this:
class Port
...
26
votes
3answers
3k views
Are integration tests meant to repeat all unit tests?
Let's say I have a function (written in Ruby, but should be understandable by everyone):
def am_I_old_enough?(name = 'filip')
person = Person::API.new(name)
if person.male?
return person....
0
votes
1answer
48 views
Historic (and prehistoric) dates in Ruby [closed]
In Ruby, is there a standard class or gem to work with dates that can be - but are not required to be - historical in nature? The dates have precision (to the nearest million years, decade, century, ...
1
vote
0answers
88 views
Choosing Between Ruby and Python for a FS Microservice Backend in Node App [closed]
I have been working on a application that up until now has been pure Node. However I am concerned about performance and overhead since the application performs a lot of file system operations (Copy ...
2
votes
0answers
69 views
Best way to build a JSON API coupled with HTML views in a Rails project
I've got a Rails eCommerce project communicating with an iOS app. The iOS app receives JSON data from the Rails back-end, but there's also HTML rendering when a user comes to the project from his ...
8
votes
4answers
223 views
When in your language classes are objects too, does the Liskov substitution principle apply to their interfaces?
According to Wikipedia the Liskov substitution principle states that
objects in a program should be replaceable with instances of their
subtypes without altering the correctness of that program
...
2
votes
3answers
186 views
Using multiple languages
I currently have a website running PHP laravel. We came to a point where we want to add a user-backend -- where users sign-up and can access functions when logging in.
My question is; Is it possible ...
3
votes
1answer
243 views
How to implement a (truly) global variable in a Rails app
How can I best implement a global counter in a Rails API app? (A central component in a system with several.)
Basically I have a transaction id I need to increment and roll over past a maximum value. ...
1
vote
1answer
108 views
Ruby: Abusing mixin
I'm currently working with some code that IMO has abused ruby's mixin features. Given that I'm new to ruby, I wonder if MO in IMO is correct or not.
My primary question is what makes more sense (and ...
3
votes
1answer
224 views
How do I go about setting up my Sinatra REST API on a server?
I'm an iOS developer primarily. In building my current app, I needed a server that would have a REST API with a couple of GET requests. I spent a little time learning Ruby, and landed on using Sinatra,...
9
votes
1answer
242 views
Python's join seems to focus not on the items to join, but on the symbol, as compared to Ruby or Smalltalk, for a design reason?
I thought one of the cornerstone of OOP is that, we have objects, which are the items we are interested in dealing with, and then we send messages to them.
So it may seem natural that, I have a ...
6
votes
1answer
158 views
Testing procedural code
TL;DR. Writing procedural code within a DB transaction. How can I improve design of the code so it's better testable?
In my application I have a service object that perform multiple things within the ...
0
votes
2answers
116 views
Using symbols instead of strings in conditions
I usually have if/else conditions which involves comparing values with a constant string.
Is it really advantageous to use symbols in such cases or use string.
For eg.
if status == 'submitted'
...
...
5
votes
4answers
758 views
Ruby: if variable vs if variable.nil?
I'm new to Ruby and I was surprised when I found out that all objects are true apart from nil and false. Even 0 is true.
A nice thing about that property of the language is that you can write:
if !...
0
votes
1answer
85 views
Does extending a ruby class violate the LSP?
I am reading about SOLID principles. In Ruby tutorials and code samples, I often see subclass extensions like:
class House
attr_reader :items
end
class Room < House
attr_reader :chair
end
p ...
0
votes
1answer
195 views
Ruby best practices for Data Access layers
I'm starting my way into Ruby development and have some questions that I hope you can give your best opinion to better design some command line applications I'm developing.
What are the best patterns ...
5
votes
2answers
596 views
How are scripting languages compiled?
I know the term "scripting languages" is just a subset of programming languages, but I want to refer to programming languages such as Python and Ruby among others.
First of all, why don't we need a ...
1
vote
0answers
73 views
Where did the tradition of new releases on Christmas Day start? [closed]
Perl 6 is being released on Christmas Day this year. I'm familiar with Ruby having a history of releases on Christmas Day, going back as far as Ruby 1.0 in 1996 if not further. However, a quick scan ...
1
vote
0answers
134 views
Terminology - Difference between thread and process and how they manage DB connections
I've been working more with concurrency in Ruby recently, and I keep seeing various articles using "threads" and "process" interchangeably.
What are the actual definitions of these terms? Is a ...
3
votes
1answer
444 views
Android App with Ruby Backend Server
I'm working on a personal project to help me branch out and learn some new/different technologies. I'm a .NET programmer but I want to learn Ruby and how to develop Android apps. I have developed ...
0
votes
1answer
331 views
Best way to design a database interface [duplicate]
This is my situation
I have a website, mobile client and desktop client.
They can all pretty much do the same operations (website might be able to do more now but in the future they might have the ...
1
vote
0answers
168 views
Securing a private API used by an iOS App
I have an app that uses an API server and I do not want to have anything other than it to be able to use that API. I know this isn't totally possible, but I want to do what I can.
I don't think my ...
-2
votes
1answer
301 views
Why is Ruby's interpreter so small? [closed]
I noticed that the filesize of Ruby's interpreter seems suspiciously small.
I would have expected /bin/dash to be the smallest of all, but is 20x larger than Ruby:
Interpreter Bytes
-----------...
1
vote
2answers
720 views
Is the time complexity of a while loop with three pointers different than 3 nested for loops?
This program (written in ruby) finds the largest 3 numbers in an array (without sorting the array). It has a while loop with three pointers. My fist instinct, since there is only one loop is to say ...
0
votes
3answers
185 views
Would it be possible to create a language similar to Ruby/Python with static typing that had the speed/memory usage of a compiled C program? [closed]
One of the main drawbacks of Ruby/Python is performance. I understand that they are interpreted and C is compiled. (And there are things like JRuby which do JIT compilation with Ruby). But they never ...
10
votes
8answers
3k views
How do I design a subclass whose method contradicts its superclass? [duplicate]
How do I design a subclass whose method contradicts its superclass? Let's say we have this example:
# Example 1
class Scissor
def right_handed?
true
end
end
class LeftHandedScissor < ...
0
votes
2answers
117 views
Refactoring case-when statement [duplicate]
The Product model which can have 2 price tables. The method price calculates the price of the product based on product's price table which is defined by price_table field.
class Product < ...
2
votes
3answers
439 views
Which is the convention in Rails to perform calculations and display the results?
So I'm working on a personal project on Rails to learn more about this framework, and I wanted to add a feature in which the user choose a particular record from the view, and after some calculations ...
1
vote
4answers
872 views
What is the “correct” way to store functions in a database?
Note: Yes, I know that storing functions in databases should be punishable by law.
We are developing a financial web application using PostgreSQL, Sinatra and AngularJS. As you may have guessed, a ...
1
vote
3answers
102 views
Replace repeated timestamp with variable in tests
I have couple hundred tests and I work with date/time a lot. In some tests, I aim for output format, elsewhere, I check date ranges. Therefore, my tests have lots of these:
FactoryGirl.create(:foo, ...
2
votes
1answer
197 views
What's the best practice for adding a lot of attributes to a Rails model?
So, I'm building an API wrapper gem that works with Spree's Product model. The API provides extensive customization of the data you send to it. I would like a user of the gem to be able to take ...
1
vote
2answers
252 views
Ruby Terminology Question: Implicit Declaration or no declaration at all?
I have a question, because in most serious sources I read, all say the same No variable is ever declared in Ruby, but still I have doubts, because according to what I was taught in my university ...
2
votes
0answers
77 views
Writing a gem supporting compiled languages with Rake. How to test?
I want to create a gem that extends the functionality of Rake, creating commands for compiling .NET code.*
Basically, I want to be able to write a Rakefile like this:
desc "Build main executable"
...
-1
votes
1answer
140 views
Is obsolete to study older versions of Ruby and RoR? [closed]
I want to study Ruby and RoR for some things I'll have to make, but almost every book, videos or any kind of source I find is outated, where the most current book I could find (link here) is one of ...
0
votes
1answer
143 views
How can I write these services using SOLID and keep them easy to test?
I am trying to write a couple of classes using SOLID principles and having some trouble.
The problem is quite simple. I have an application that tracks leads. Leads are created when events are raised ...
1
vote
2answers
550 views
How does the consumer-producer solution work?
I'm only a beginner, and my book doesn't cover this subject. I have researched my problem and found that an implementation of the consumer-producer pattern is the ideal solution, and have Googled it, ...
2
votes
1answer
82 views
BloomFilter in ruby should have k hash functions
I am reading the Bloom Filter implementation written in ruby. It should have k hash functions, but it looks like the same hash function is being used with different seed values. Is this a common way ...
0
votes
1answer
83 views
What would be the return type of a cartesian product of a multiset
I am writing a Multiset in Ruby. The Union, Intersection operations where simple and return a MultiSet. But, I am not sure what the return type of the cartesian product should be, should I return an ...
3
votes
2answers
105 views
Is a guardfile part of the private developers environment or the public OSS project?
Let us say I have an open source project on github. Now I wish to include tools required to develop the project so others can easily contribute. It is hard for me to tell when these tools should be ...
1
vote
1answer
56 views
Create a collection with “average points” of N items from a pool with items of various points
Let's say I have a question pool to generate exams out of it. Each question contains a difficulty from 1 (hard) to 99 (easy). The questions are available in a hash / array (adapt to your favorite ...
1
vote
1answer
100 views
How do rails project know about rake tasks from other repositories
We have a rake task called db:sanity_check which exists in a 'core' repo.
Other repositories that we have also show this rake task.
But they do not define the rake task. It 'comes' from core'
How ...
