To get a list of breakpoints you can use info breakpoint. You can see how using the command break and a line number you can set your breakpoints. So you will have to consult the documentation. Usually you would call the help command, but in this case it is lacking a bit on information:
#Rubymine debug rails code#
Let's see how you can set breakpoints and debug you code inside byebug! One of the cons of using Byebug over pry is that it doesn't provide syntax highlighting. If you want to use it for the former then you just drop byebug instead of binding.pry where you want your code to stop. For example, you can use the ls command to see what methods and instance variables an object has access to.ĭon't forget to run the help command to get a listing of all the goodies! Another Ruby Debugger: Byebugīyebug can act as a pry replacement or as a gdb-like debugger for Ruby. If you want to completely quit a pry session you can type exit!, if you do a regular exit it runs your program until the next breakpoint. This is what you will see when you are dropped on a pry session: What I like to do is to have a macro/snippet on my editor that already includes the require in the same line than the breakpoint, so when I delete it I will be deleting both things. That won't be very helpful for a rails app, so you may want to add pry to your Gemfile. If you just want to do it temporarily then you can call your ruby script like this: You will also need to require pry into your project (require 'pry').
#Rubymine debug rails install#
Using pry you can make your code stop at a specific line of code (also known as a breakpoint) and it will drop you into an irb-like environment, where you can evaluate ruby code in the context of your project, or execute one of the many useful pry commands.Īll you have to do is drop binding.pry where you would like to install a pry breakpoint. When you have many variables to check, adding puts everywhere might not be very practical. Using p is equivalent to saying puts variable.inspect, and it’s useful for looking at objects.
The most basic (which doesn’t necessarily mean bad) debugging technique that you are probably familiar with is just dumping the values of the suspected variables. If that doesn’t help then you will need to find more information, like the values of the affected variables.See if anything obvious jumps out to you and fix it (look for things mentioned on the error message).If it isn’t, keep going down the stack trace until you find the first reference to a file you recognize If the file is part of your project: open the faulting file on the indicated line number.Here is a general algorithm for dealing with a stack trace: It’s basically a method chain, if you keep going down you should eventually find the main method of your app. Undefined local variable or method ‘ invalid_variable‘Īs you can see the error is not that intimidating when broken down in this way.īy the way, you can find a list of exceptions here.Įvery line in the stack trace below the first one tells you how the code got here. However, it is a good point to start our investigation. This is where the actual error occurred, but it doesn’t mean the error condition originated here. tmp/stack.rb:6:in 'method2': undefined local variable or method 'invalid_variable' for main:Object (NameError) Running this code will give you the following error: If the problem is that your program is crashing, it is important to pay attention to the error message, which usually will contain clues of what’s going wrong. When you are getting an error from the Ruby interpreter or your program is not doing what it should be doing then it’s time to put on your debugging hat.
#Rubymine debug rails how to#
Using the techniques discussed in this article you will learn how to deal with this issue and similar problems! Understanding Errors & Stack Traces This means that a nil value managed to find it’s way into our code.
You may be familiar with the following error message: undefined method 'some_method' for nil:NilClass Many times our programs dont’t work like we expect, so we have to use the art of debugging ruby to help us finding out why. How often does your program do exactly what you want the first time around?
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