Let's say we have:
task :something => [:something_else] do
# some of stuff
end
task :something_else do
# some verbose stuff
# some quiet stuff
end
Now I want something_else to do the verbose stuff when called from the shell (rake something_else) and the silent ones when called as a dependency to rake something.
i think it might be a better idea to work with parameters or different tasks instead.
one thing that you could do is look for top-level task like that:
task :something_else do |t|
puts "some verbose stuff" if t.application.top_level_tasks.include? 'something_else'
puts "some quiet stuff"
end
You could look what was passed to ARGV. For example:
task :something_else do
if ARGV[0] == 'something_else'
puts "Verbose Stuff!"
end
end
Related
I create test code with rspec. I want to test callback is executed or not.
task main: [:callback] means run callback before main, doesn't it?
But my test failed. I looks like callback is not executed. Why?
require 'rails_helper'
require 'rake'
RSpec.describe 'Rake::Task' do
before(:all) do
#rake = Rake::Application.new
Rake.application = #rake
Rake.application.rake_require('rspec_before', ["#{Rails.root}/lib/tasks"])
end
subject { #rake['rspec_before:main'].execute }
it "expects run callback before main task" do
expect{ subject }.to output(/Hello, world/).to_stdout
end
end
My Rake task is below.
namespace :rspec_before do
task :callback do
#greeting = "Hello, world"
end
# case 1
# In this case, `callback` is NOT executed in rspec
# In console, `callback` is executed !!!!
desc "main task"
task main: [:callback] do
puts #greeting
end
# case 2
# In this case, `callback` is executed in rspec
# task :main do
# Rake::Task['rspec_before:callback'].execute
# puts #greeting
# end
end
So, I'm not sure I would call :callback a callback, it's more of a dependency. A callback implies it happens after the main task is done, whereas when you do
task main: [:callback]
what you're really saying is that you depend on the other task having run first. So I would end up changing the name of that, though that's probably just a sample/throwaway name for this question. But, I digress and I'll continue calling the task :callback as written for this answer.
The main issue here is that when you call execute on a rake task, only that task gets executed. This is because there may be situations where you don't want or need to call the entire dependency chain. Let's say we add another task to your file:
desc "secondary task"
task :secondary do
#greeting = 'Goodbye, Cruel World'
Rake::Task['rspec_before:main'].execute
end
If we run this, we very likely want the main task to output Goodbye, Cruel World, instead of Hello, World and if we call all the dependencies, main would end up calling :callback which would override our #greeting and end up outputting Hello, World.
There is, however, another task that does call the entire dependency chain: invoke:
desc "secondary task"
task :secondary do
#greeting = 'Goodbye, Cruel World'
Rake::Task['rspec_before:main'].invoke
end
if we run this task, now we'll see Hello, World instead of Goodbye, Cruel World. So, having said all of this, what does that mean for your RSpec test? You simply need to change your subject to:
subject { #rake['rspec_before:main'].invoke }
because you are wanting to run the dependencies.
I have a rake task, that depends on another in terms of that it parses its output to determine failure or success.
Currently I do it like this:
task :foo do
puts "OK"
end
task :bar do
if `bundle exec rake foo`.split(/\n/)[-1] == "OK" then
puts "Everything went fine"
else
puts "Something went wrong"
exit 1
end
end
But I would prefer not to run the dependency in a subshell but specify it correctly as in task bar: :foo do and then check its output, is something like that possible?
Follow this, it calls one task from other. It helps.
namespace :abc do
task :aa do
"ok"
end
task :bb do
op = Rake::Task["abc:aa"].enhance(["abc:aa"])
p "op=> #{op}"
end
end
Is there a straight forward way to modify a Rake task to run some bit of code before running the existing task? I'm looking for something equivalent to enhance, that runs at the beginning rather than the end of the task.
Rake::Task['lame'].enhance(['i_run_afterwards_ha_ha'])
You can use the dependency of Rake task to do that, and the fact that Rake allows you to redefine existing task.
Rakefile
task :your_task do
puts 'your_task'
end
task :before do
puts "before"
end
task :your_task => :before
As result
$ rake your_task
before
your_task
Or you could use the rake-hooks gem to do before and after hooks:
https://github.com/guillermo/rake-hooks
namespace :greetings do
task :hola do puts "Hola!" end ;
task :bonjour do puts "Bonjour!" end ;
task :gday do puts "G'day!" end ;
end
before "greetings:hola", "greetings:bonjour", "greetings:gday" do
puts "Hello!"
end
rake greetings:hola # => "Hello! Hola!"
I have the following example which is based on the structure i want my rakefile to use:
task :default do
puts 'Tasks you can run: dev, stage, prod'
end
task :dev => [:init,:devrun,:clean]
task :devrun do
puts 'Dev stuff'
end
task :stage => [:init,:stagerun,:clean]
task :stagerun do
puts 'Staging stuff'
end
task :prod => [:init,:prodrun,:clean]
task :prodrun do
puts 'Production stuff'
end
task :init do
puts 'Init...'
end
task :clean do
puts 'Cleanup'
end
Will the tasks always be run in the same order? I read somewhere that they wouldn't, and somewhere else that they would, so i'm not sure.
Or if you can suggest a better way to do what i'm trying to achieve (eg have a common init and cleanup step surrounding a depending-upon-environment step), that'd also be good.
Thanks
From the Rake source code:
# Invoke all the prerequisites of a task.
def invoke_prerequisites(task_args, invocation_chain) # :nodoc:
#prerequisites.each { |n|
prereq = application[n, #scope]
prereq_args = task_args.new_scope(prereq.arg_names)
prereq.invoke_with_call_chain(prereq_args, invocation_chain)
}
end
So it appears that the code normally just iterates the array and runs the prerequisite tasks sequentially.
However:
# Declare a task that performs its prerequisites in parallel. Multitasks does
# *not* guarantee that its prerequisites will execute in any given order
# (which is obvious when you think about it)
#
# Example:
# multitask :deploy => [:deploy_gem, :deploy_rdoc]
#
def multitask(args, &block)
Rake::MultiTask.define_task(args, &block)
end
So you are right, both can be true, but order can only be off if you prefix your task with multitask It looks like regular tasks are run in order.
According to http://rake.rubyforge.org/files/doc/rakefile_rdoc.html, you can create a task that accepts parameters and also has prerequisites:
task :name, [:first_name, :last_name] => [:pre_name] do |t, args|
But what if :pre_name is a task that also accepts parameters? What is the syntax for passing parameters to :pre_name when it is used as a prerequisite?
It's actually pretty simple - the :pre task will receive the same parameters as the original task. All you need to do is make sure that the signature is similar - for instance if the first task receives :a,:b the :pre task needs to receive them as well.
See more here: rake with params
I know I'm late to the party, but I had the same problem and figured something out that didn't use environment variables. You can use Rake::Task.invoke to do this. Here's an example for a database backup rake task:
namespace :db do
task :dump_db, [:dump_file, :rails_env] do |t, args|
puts "dumping to #{args[:dump_file]} with rails env = #{args[:rails_env]}"
end
task :stop_slave do
puts "stopping slave"
end
task :start_slave do
puts "starting slave"
end
task :upload_dump, [:dump_file] do |t, args|
puts "uploading #{args[:dump_file]}"
end
task :backup_to_s3, [:dump_file, :rails_env] do |t, args|
Rake::Task["db:stop_slave"].invoke()
Rake::Task["db:dump_db"].invoke(args[:dump_file], args[:rails_env])
Rake::Task["db:start_slave"].invoke()
Rake::Task["db:upload_dump"].invoke(args[:dump_file])
end
end
I don't have a direct answer, but I do have an alternative solution that might work for you. None of my rake tasks use parameters. (I think I tried to use parameters and had trouble getting them to work.) Instead, I rely on the ENV array. So, for example, I would write that example task as:
task :name =>:pre_name do
do_something_with_name(ENV['first_name'], ENV['last_name'])
end
which would be invoked as:
$ rake name first_name=John last_name=Smith
The ENV array data would be available to the pre_name task as well.
namespace :shell do
desc "Local hostname"
task :hostname do
puts "Local hostname"
sh "hostname"
end
desc "Local uptime"
task :uptime do
puts "Local uptime"
sh "uptime"
end
desc "Echo something"
task :echo,[:someword] do |t,args|
puts "--- #{args[:someword]} ---"
end
end
desc "Run all tasks"
task :all , [:someword] => ["shell:hostname","shell:uptime","shell:echo"] do
puts "Done."
end