How can I tell if Rails code is being run via rake or script/generate?

Question

I've got a plugin that is a bit heavy-weight. (Bullet, configured with Growl notifications.) I'd like to not enable it if I'm just running a rake task or a generator, since it's not useful in those situations. Is there any way to tell if that's the case?

See this answer to further distinguish between `rake`, `rails c`, `rails s`, `rails g`: https://stackoverflow.com/a/53963584/293280 — Joshua Pinter, Dec 28 '18 at 21:31

score 39 · Accepted Answer · edited Oct 17 '18 at 03:51

39

It's as simple as that:

if $rails_rake_task
  puts 'Guess what, I`m running from Rake'
else
  puts 'No; this is not a Rake task'
end

Rails 4+

Instead of $rails_rake_task, use:

File.basename($0) == 'rake'

edited Oct 17 '18 at 03:51

Joshua Pinter

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answered Apr 02 '13 at 14:46

slaxor

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This works, but it's ugly, because it depends on Rake internally defining a global variable - which might go away in the future – Tilo Feb 18 '14 at 21:51
15

In Rails 4, the above didn't work for me, but **if File.basename($0) == 'rake'** still did. – codenoob Mar 02 '14 at 04:07
2

This doesn't work now that running rake tasks via `rails` is SOP. – dleavitt Jul 07 '18 at 00:28
2

It's actually preferred to use `$PROGRAM_NAME` instead of `$0` to be more explicit. – Joshua Pinter Oct 17 '18 at 03:50

score 9 · Answer 2 · answered Feb 18 '14 at 21:48

9

I like NickMervin's answer better, because it does not depend on the internal implementation of Rake (e.g. on Rake's global variable).

This is even better - no regexp needed

  File.split($0).last == 'rake'

File.split() is needed, because somebody could start rake with it's full path, e.g.:

  /usr/local/bin/rake taskname

answered Feb 18 '14 at 21:48

Tilo

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1

Given some recent experiences trying to determine if the environment is running within rake, testing $0 is the most reliable. defined?(::Rake) seemed to always be true, at least in Rails, so that did not work. I looked for global variables but did not find anything suitable. – Martin Streicher Mar 31 '14 at 13:26

score 6 · Answer 3 · answered Jan 13 '13 at 02:28

6

$0 holds the current ruby program being run, so this should work:

$0 =~ /rake$/

answered Jan 13 '13 at 02:28

NickMerwin

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score 4 · Answer 4 · answered Aug 20 '20 at 19:24

4

The most stable option is to add $is_rake = true at the beginning of Rakefile and use it from your code.

Use of $0 or $PROGRAM_NAME sometimes will fail, for example when using spring and checking variables from config/initializers

answered Aug 20 '20 at 19:24

Daniel Garmoshka

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score 3 · Answer 5 · answered Mar 18 '10 at 02:43

It appears that running rake will define a global variable $rakefile, but in my case it gets set to nil; so you're better off just checking if $rakefile has been defined... seeing as __FILE__ and $FILENAME don't get defined to anything special.

$ cat test.rb 
puts(global_variables.include? "$rakefile")
puts __FILE__
puts $FILENAME
$ cat Rakefile 
task :default do
    load 'test.rb'
end
$ ruby test.rb
false
test.rb
-
$ rake
(in /tmp)
true
./test.rb
-

Not sure about script/generator, though.

score 1 · Answer 6 · answered Feb 25 '15 at 06:55

1

You can disable the plugin using environment variable:

$ DISABLE_BULLET= 1 rake some:task

And then in your code:

unless ENV['DISABLE_BULLET']
end

answered Feb 25 '15 at 06:55

x-yuri

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score 1 · Answer 7 · answered Mar 29 '21 at 00:22

We could ask this

Rake.application.top_level_tasks

In a rails application, this is an empty array, whereas in a Rake task, the array has the task name in it.

top_level_tasks probably isn't a public API, so it's subject to changes. But this is the only thing I have found.

How can I tell if Rails code is being run via rake or script/generate?

7 Answers7

Rails 4+

Linked