research build wiring rakefile setup

Rakefile Setup

Current Rakefile

Source: Rakefile

# frozen_string_literal: true

require "bundler/gem_tasks"
require "minitest/test_task"

Minitest::TestTask.create

require "standard/rake"

task default: %i[test standard]

No compile task and no Rake::ExtensionTask. Running bundle exec rake will run tests (which will fail once require "duckling/duckling" is added to lib files) and StandardRB lint only.

Verified reference: rust_blank Rakefile

Source: examples/rust_blank/Rakefile

# frozen_string_literal: true

require "rake/testtask"
require "rake/extensiontask"

task default: :test

Rake::ExtensionTask.new("rust_blank") do |c|
  c.lib_dir = "lib/rust_blank"
end

task :dev do
  ENV['RB_SYS_CARGO_PROFILE'] = 'dev'
end

Rake::TestTask.new do |t|
  t.deps << :dev << :compile
  t.test_files = FileList[File.expand_path("test/*_test.rb", __dir__)]
end

Key observations:

• rake/extensiontask is required (comes from the rake-compiler gem, which is pinned to 1.2.9 in Gemfile.lock)
• Rake::ExtensionTask.new("rust_blank") matches the gemspec extension name
• c.lib_dir = "lib/rust_blank" places the compiled .so/.bundle in lib/rust_blank/ so that require "rust_blank/rust_blank" works
• The test task has t.deps << :dev << :compile — tests depend on compilation
• A :dev task sets RB_SYS_CARGO_PROFILE = 'dev' for faster debug builds

Changes needed for the duckling Rakefile

Add after the existing requires:

require "rake/extensiontask"

Rake::ExtensionTask.new("duckling") do |ext|
  ext.lib_dir = "lib/duckling"
end

The argument "duckling" to ExtensionTask.new must match the extension name in duckling.gemspec — the gemspec declares spec.extensions = ["ext/duckling/extconf.rb"], and ExtensionTask derives the shared library name from this.

Update the default task to include compilation:

task default: %i[compile test standard]

Why lib_dir = "lib/duckling"

create_rust_makefile("duckling/duckling") in extconf.rb tells rb_sys to put the compiled library at the path duckling/duckling relative to lib/. That resolves to lib/duckling/duckling.bundle (macOS) or lib/duckling/duckling.so (Linux).

Rake::ExtensionTask needs to know this target directory so that when rake compile runs, it moves the compiled artifact from the build staging area into the correct location in lib/.

Setting ext.lib_dir = "lib/duckling" tells ExtensionTask that the output belongs in lib/duckling/, which matches the extconf.rb path argument and allows require "duckling/duckling" to find the file.

Optional: dev task for faster iteration

Following the rust_blank pattern, a :dev task can be added to speed up the edit-compile-test loop during development:

task :dev do
  ENV["RB_SYS_CARGO_PROFILE"] = "dev"
end

Used as: bundle exec rake dev compile test

Without this, cargo defaults to the release profile (slower compile, faster runtime). During development the dev profile is preferred.

rake-compiler version

rake-compiler is a development dependency in gemspec: spec.add_development_dependency "rake-compiler", "~> 1.2.0" and Gemfile.lock pins it to 1.2.9. Rake::ExtensionTask is provided by this gem.

Resolved (were open questions)

1. Does Minitest::TestTask.create support deps? No need — the shipped Rakefile (main@03a69e1) doesn't attempt to wire Minitest::TestTask.create with explicit deps at all. It relies purely on the default task's array ordering (task default: %i[standard compile test]), confirmed empirically below. Filed issue #30 to explore making test explicitly depend on :compile (task test: :compile or similar) so bundle exec rake test alone — not just the default task — also compiles first.

2. Does task default: %i[compile test standard] guarantee compile runs before test? Confirmed empirically with the installed Rake 13.4.2:

   task :c do puts "RAN: c" end
   task :a do puts "RAN: a" end
   task :b do puts "RAN: b" end
   task default: %i[c a b]
   Rake::Task[:default].invoke
   # => RAN: c
   #    RAN: a
   #    RAN: b

   Rake invokes prerequisites in the array's listed order. task default: %i[standard compile test] (the shipped ordering) runs standard (lint), then compile, then test, in that order, every time.

Follow-up: the :dev task was never added

The shipped Rakefile has no :dev task — bundle exec rake compile always builds in the release Cargo profile (slower compile, faster runtime), even during local development. Filed issue #31 to add the RB_SYS_CARGO_PROFILE=dev task described above for a faster edit-compile-test loop.