feat: implement context helper

.rubocop.yml

@@ -1,5 +1,5 @@
 AllCops:
-  TargetRubyVersion: 2.6
+  TargetRubyVersion: 2.7
 
 Style/StringLiterals:
   Enabled: true

LICENSE.txt

@@ -1,6 +1,6 @@
 The MIT License (MIT)
 
-Copyright (c) 2022 TODO: Write your name
+Copyright (c) 2022 Masaaki Aoyagi <masaaki.aoyagi@gmail.com>
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

README.md

@@ -1,4 +1,4 @@
-# Rspec::ContextHelper
+# RSpec::ContextHelper
 
 Welcome to your new gem! In this directory, you'll find the files you need to be able to package up your Ruby library into a gem. Put your Ruby code in the file `lib/rspec/context_helper`. To experiment with that code, run `bin/console` for an interactive prompt.
 
@@ -34,4 +34,4 @@ The gem is available as open source under the terms of the [MIT License](https:/
 
 ## Code of Conduct
 
-Everyone interacting in the Rspec::ContextHelper project's codebases, issue trackers, chat rooms and mailing lists is expected to follow the [code of conduct](https://github.com/[USERNAME]/rspec-context_helper/blob/master/CODE_OF_CONDUCT.md).
+Everyone interacting in the RSpec::ContextHelper project's codebases, issue trackers, chat rooms and mailing lists is expected to follow the [code of conduct](https://github.com/[USERNAME]/rspec-context_helper/blob/master/CODE_OF_CONDUCT.md).

lib/rspec/context_helper.rb

@@ -1,10 +1,48 @@
 # frozen_string_literal: true
 
+require "rspec"
+
 require_relative "context_helper/version"
 
-module Rspec
+module RSpec
   module ContextHelper
-    class Error < StandardError; end
-    # Your code goes here...
+    def context_with(description = nil, metadata: nil, shared: nil, **values, &block)
+      description ||= to_sentence(values.map { |k, v| "#{k} is #{v.inspect}" }).then do |desc|
+        desc.empty? ? desc : "when #{desc}"
+      end
+
+      context description do
+        values.each do |key, value|
+          let(key) do
+            value.is_a?(::Proc) ? instance_exec(&value) : value
+          end
+        end
+        instance_exec(&block)
+      end
+    end
+
+    def example_with(description = nil, metadata: nil, shared: nil, **values, &block)
+      context_with(description, metadata: metadata, shared: shared, **values) do
+        example { instance_exec(&block) }
+      end
+    end
+
+    private def to_sentence(words)
+      case words.size
+      when 0
+        ""
+      when 1
+        words[0]
+      when 2
+        words.join(" and ")
+      else
+        *rest, last = words
+        [rest.join(", "), last].join(" and ")
+      end
+    end
   end
 end
+
+RSpec.configure do |config|
+  config.extend RSpec::ContextHelper
+end

lib/rspec/context_helper/version.rb

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-module Rspec
+module RSpec
   module ContextHelper
     VERSION = "0.1.0"
   end

rspec-context_helper.gemspec

@@ -4,21 +4,21 @@ require_relative "lib/rspec/context_helper/version"
 
 Gem::Specification.new do |spec|
   spec.name = "rspec-context_helper"
-  spec.version = Rspec::ContextHelper::VERSION
-  spec.authors = ["TODO: Write your name"]
-  spec.email = ["TODO: Write your email address"]
+  spec.version = RSpec::ContextHelper::VERSION
+  spec.authors = ["Masaaki Aoyagi"]
+  spec.email = ["masaaki.aoyagi@gmail.com"]
 
-  spec.summary = "TODO: Write a short summary, because RubyGems requires one."
-  spec.description = "TODO: Write a longer description or delete this line."
-  spec.homepage = "TODO: Put your gem's website or public repo URL here."
+  spec.summary = "context helpers for RSpec"
+  spec.description = "context helpers for RSpec"
+  spec.homepage = "https://github.com/masaakiaoyagi/rspec-context_helper.rb"
   spec.license = "MIT"
-  spec.required_ruby_version = ">= 2.6.0"
+  spec.required_ruby_version = ">= 2.7.0"
 
   spec.metadata["allowed_push_host"] = "TODO: Set to your gem server 'https://example.com'"
 
   spec.metadata["homepage_uri"] = spec.homepage
-  spec.metadata["source_code_uri"] = "TODO: Put your gem's public repo URL here."
-  spec.metadata["changelog_uri"] = "TODO: Put your gem's CHANGELOG.md URL here."
+  spec.metadata["source_code_uri"] = "https://github.com/masaakiaoyagi/rspec-context_helper.rb"
+  spec.metadata["changelog_uri"] = "https://github.com/masaakiaoyagi/rspec-context_helper.rb"
 
   # Specify which files should be added to the gem when it is released.
   # The `git ls-files -z` loads the files in the RubyGem that have been added into git.
@@ -31,9 +31,7 @@ Gem::Specification.new do |spec|
   spec.executables = spec.files.grep(%r{\Aexe/}) { |f| File.basename(f) }
   spec.require_paths = ["lib"]
 
-  # Uncomment to register a new dependency of your gem
-  # spec.add_dependency "example-gem", "~> 1.0"
+  spec.add_dependency "rspec", "~> 3.11"
 
-  # For more information and examples about making a new gem, check out our
-  # guide at: https://bundler.io/guides/creating_gem.html
+  spec.add_dependency "pry-byebug"
 end

sig/rspec/context_helper.rbs

@@ -1,4 +1,4 @@
-module Rspec
+module RSpec
   module ContextHelper
     VERSION: String
     # See the writing guide of rbs: https://github.com/ruby/rbs#guides

spec/rspec/context_helper_spec.rb

@@ -1,11 +1,87 @@
 # frozen_string_literal: true
 
-RSpec.describe Rspec::ContextHelper do
-  it "has a version number" do
-    expect(Rspec::ContextHelper::VERSION).not_to be nil
+RSpec.describe RSpec::ContextHelper do
+  let(:description) { self.class.description }
+
+  describe ".context_with" do
+    describe "description" do
+      context_with do
+        example { expect(description).to eq("") }
+      end
+
+      context_with "message" do
+        example { expect(description).to eq("message") }
+      end
+
+      context_with a: "1" do
+        example { expect(description).to eq(%(when a is "1")) }
+      end
+
+      context_with a: "1", b: "2" do
+        example { expect(description).to eq(%(when a is "1" and b is "2")) }
+      end
+
+      context_with a: "1", b: "2", c: "3" do
+        example { expect(description).to eq(%(when a is "1", b is "2" and c is "3")) }
+      end
+    end
+
+    context_with do
+      example {}
+    end
+
+    context_with "message" do
+      example {}
+    end
+
+    context_with a: "1" do
+      example { expect(a).to eq("1") }
+    end
+
+    context_with "message", a: -> { b }, b: "2", c: -> { -> {} } do
+      example { expect(a).to eq("2") }
+      example { expect(b).to eq("2") }
+      example { expect(c).to be_an_instance_of(Proc) }
+    end
   end
 
-  it "does something useful" do
-    expect(false).to eq(true)
+  describe ".example_with" do
+    describe "description" do
+      example_with do
+        expect(description).to eq("")
+      end
+
+      example_with "message" do
+        expect(description).to eq("message")
+      end
+
+      example_with a: "1" do
+        expect(description).to eq(%(when a is "1"))
+      end
+
+      example_with a: "1", b: "2" do
+        expect(description).to eq(%(when a is "1" and b is "2"))
+      end
+
+      example_with a: "1", b: "2", c: "3" do
+        expect(description).to eq(%(when a is "1", b is "2" and c is "3"))
+      end
+    end
+
+    example_with do
+    end
+
+    example_with "message" do
+    end
+
+    example_with a: "1" do
+      expect(a).to eq("1")
+    end
+
+    example_with "message", a: -> { b }, b: "2", c: -> { -> {} } do
+      expect(a).to eq("2")
+      expect(b).to eq("2")
+      expect(c).to be_an_instance_of(Proc)
+    end
   end
 end

spec/spec_helper.rb

@@ -1,5 +1,7 @@
 # frozen_string_literal: true
 
+require "pry"
+
 require "rspec/context_helper"
 
 RSpec.configure do |config|