Populating instance variables in rspec tests

ruby rspec stubbing
Joseph Le Brech picture Joseph Le Brech · Oct 25, 2012 · Viewed 11.8k times · Source

I have a class which has the following initialise method.

def initialize(my_var)
  @my_var = my_var
end

and I want to test the method which then does something to @my_var

def split
  @my_var.split(",")
end

how do I change @my_var before testing that it returns an array properly?

Is this possible without having an accessor for @my_var?

Answer

PinnyM picture PinnyM · Oct 25, 2012

This doesn't sound like a correct practice. Rspec should be testing the interface behavior of your classes and models - not the internal implementation (of which instance variables undoubtedly are). There are ways to do this, but are you sure you don't want to have an accessor for that variable?

Anyhow, you can use my_object.instance_variable_get("@my_var") and my_object.instance_variable_set("@my_var", value) to manipulate the variable.

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