Saturday🪩Night🦫Beaver

Project codename: Saturday🪩Night🦫Beaver. Implementation/package/module name: Crake.

A Crystal port of Ruby's Rake build tool, now with a little extra disco-beaver energy.

VS Code Tasks

This workspace now includes two editor tasks:

• 👀🧪 Saturday🪩Night🦫Beaver spec watcher — the default build task; reruns crystal spec --error-trace whenever files under src/, spec/, or shard.yml change.
• 🧪 Saturday🪩Night🦫Beaver specs — the default test task; runs the spec suite once with error traces enabled.

Installation

Add to your shard.yml:

dependencies:
  crake:
    github: KarlAmort/crake

Then run shards install.

Usage

Create a Crakefile.cr:

require "crake"

desc "Build the project"
task "build" do |_|
  sh "crystal build src/main.cr"
end

desc "Run tests"
task "test", deps: ["build"] do |_|
  sh "crystal spec"
end

desc "Clean build artifacts"
task "clean" do |_|
  sh "rm -rf bin/"
end

task "default", deps: ["test"]

Crake.run

Run it:

crystal run Crakefile.cr                  # Run default task
crystal run Crakefile.cr -- build         # Run specific task
crystal run Crakefile.cr -- -T            # List tasks
crystal run Crakefile.cr -- deploy[host]  # Task with arguments

Or compile for speed:

crystal build Crakefile.cr -o crake --release
./crake build

Features

Task Dependencies

task "deploy", deps: ["build", "test"] do |_|
  sh "rsync -avz build/ server:/app/"
end

Namespaces

namespace "db" do |_|
  desc "Run migrations"
  task "migrate" do |_|
    sh "bin/rails db:migrate"
  end

  desc "Seed database"
  task "seed", deps: ["db:migrate"] do |_|
    sh "bin/rails db:seed"
  end
end

File Tasks (timestamp-based)

file "output.o", deps: ["input.c"] do |_|
  sh "cc -c input.c -o output.o"
end

File Creation Tasks (existence-based)

file_create "build/" do |_|
  Dir.mkdir_p("build/")
end

Directory Tasks

directory "build/obj/debug"  # Creates all intermediate dirs

Multitasks (parallel prerequisites)

multitask "assets", deps: ["css", "js", "images"] do |_|
  puts "All assets compiled"
end

Task Arguments

task "deploy", arg_names: ["host", "user"] do |args|
  host = args["host"] || "localhost"
  user = args["user"] || "deploy"
  sh "ssh #{user}@#{host} 'deploy.sh'"
end
# Invoke: ./crake deploy[myserver,admin]

Rules (pattern-based task synthesis)

rule ".o", [".c"] do |t|
  sh "cc -c #{t.prerequisites.first} -o #{t.name}"
end

Shell Helpers

sh "make all"                    # Run command, raise on failure
output = sh_output("git rev-parse HEAD")  # Capture output

FileList (glob-based file collections)

sources = Crake::FileList["src/**/*.cr"]
sources.exclude(/spec/)

CLI Options

-T, --tasks          Display tasks with descriptions
-AT, --all           Display all tasks
-P, --prereqs        Display task prerequisites
-t, --trace          Turn on invoke/execute tracing
-n, --dry-run        Do a dry run without executing actions
-s, --silent         Suppress status output
-m, --multitask      Run all prerequisites in parallel
-B, --build-all      Build all prerequisites
-j, --jobs N         Number of parallel workers
-f, --rakefile FILE  Use FILE as the Crakefile
-V, --version        Display the version
-h, --help           Display this help

Ported from Ruby's Rake

Core classes faithfully ported:

• Task — basic tasks with dependencies and actions
• FileTask — timestamp-based file rebuild logic
• FileCreationTask — existence-based one-time tasks
• MultiTask — parallel prerequisite execution via Crystal fibers
• TaskManager — task registry, lookup, and rule synthesis
• Application — CLI parsing and task orchestration
• Scope / LinkedList — immutable namespace scoping
• InvocationChain — circular dependency detection
• TaskArguments — named argument passing with parent chains
• FileList — glob-based file collections with exclusions
• NameSpace — scoped task lookup
• Full DSL (task, file, namespace, desc, rule, sh, etc.)

License

MIT