Pulling a class from a ruby file

[Abhishek Ray]

I have a single ruby file, consisting of a class definition, and some
code outside the class. Our tech lead wants this keep all this in a
single file. I also have a unit test in a seperate ruby file which tests
the class. The problem is that I want the unit test to load only the
class without executing the code outside the class, which I can't do
with 'require' or 'load'.

Is there any way in Ruby to load only a single class from another file.

 

[Avdi Grimm]

Is there any way in Ruby to load only a single class from another file.

No.

If you only want the external code the be executed when the file is
run as an executable, and not when it is loaded by another file, you
can enclose that code in a conditional, thus:

if $0 == __FILE__
# ... code to execute when run as an executable ...
end

I haven't tested the above code. You might need to alter it to make
it more robust, along the lines of:

if File.expand_path($0) == File.expand_path(__FILE__)
# ...
end

--
Avdi

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[Joel VanderWerf]

No.

If you only want the external code the be executed when the file is
run as an executable, and not when it is loaded by another file, you
can enclose that code in a conditional, thus:

if $0 == __FILE__
# ... code to execute when run as an executable ...
end

or put the external code inside of some specialized construct:

def external
yield unless $testing
end

external do
class C
end

def foo
end
end

C
foo

 

[Mark Wilden]

def external
yield unless $testing
end

external do
class C
end

def foo
end
end

C
foo

This is cool, but is it any different than

unless $testing
class C
end
end

///ark

 

[Joel VanderWerf]

This is cool, but is it any different than

unless $testing
class C
end
end

Oh, that would too and maybe even be better, if your condition is just a
boolean. I was expecting there might be more to it than that....