如何在Rails控制台的模块中运行私有方法？

Question

I have an error in a private method in a helper file. The helper file looks something like below with module HxHelper . I want to run method_2 in rails console to recreate the error in my local system.

module HxHelper
def method_1{
"key_1": "@h.htype"
"key_2": "value_2"

 + method_2}
end

private
def method_2{
"key1": "value_1"}
end

In my controller file I define a new class and include the previous helper file. I have tried the following.

1. Created an object of my class as obj = Class.new and obj.method_1 . I get an error undefined method type in method_1. hype is attribute in house table.
2. Tried HxHeleper::method_1 : Error - method_1 is not defined in HxHelper module.
3. Defining method_2 as self : Doesn't work.

Can someone help me understand what I am doing wrong?

Answer 1

You have some syntax errors in this example. You want to use commas at the end of the lines of your hash, you can't add two hashes together, you instead need to merge. Merging will take the receiver (the thing you're calling merge on) and override any values from the argument. Additionally, when using : in your hash, your keys end up being symbols, which means you don't need the quotes.

This would be the proper way to define the helper module.

module HxHelper
  def method_1
    {
      key_1: "@h.htype",
      key_2: "value_2",
    }.merge(method_2)
  end

private
  def method_2
    {
      key1: "value_1",
    }
  end
end

Then you can use it like this:

class Test
  include HxHelper
end
t = Test.new
t.method_1

This will return:

{:key_1=>"@h.htype", :key_2=>"value_2", :key1=>"value_1"}

If you call t.method_2 , you get an error about calling a private method.

If method_2's hash had a key of key_1 instead, your return value would be:

{:key_1=>"value_1", :key_2=>"value_2"}

because the :key_1 from the argument overrode the one on the receiver Hash.

If you wanted to call that private method, you could do:

t.send(:method_2)

If you had a method that took arguments, you just add them after the symbol of the method name:

private
  def test(num1, num2)
    return(num1 + num2)
  end

  send(:test, 1, 2)

This would return 3

Answer 2

Assuming we can get around your syntax issues, the standard answer to 'how do I call a private method in Ruby?' is with .send(), as in obj.send(:private_method) .

After you manually debug this, learn to write automated tests. Rails has exemplary, industry-leading support for them. The tests will take over the role of experimentation and investigation that you are currently abusing the console for.