a sample repository of prop_check with rspec

.gitignore

# 

.rspec

# コードを gist に保存したい
# gist はフラットなファイル構造しか受けつけない
# ルート直下を探索パスに含めるために必要なオプション
-I .

# ドキュメント形式でテスト結果を示すのに必要なオプション
--format documentation

Gemfile

source "https://rubygems.org"

gem "rspec", "~> 3.12"

gem "prop_check", "~> 0.18.1"

Gemfile.lock

GEM
  remote: https://rubygems.org/
  specs:
    amazing_print (1.5.0)
    diff-lcs (1.5.0)
    prop_check (0.18.1)
      amazing_print (~> 1.2)
    rspec (3.12.0)
      rspec-core (~> 3.12.0)
      rspec-expectations (~> 3.12.0)
      rspec-mocks (~> 3.12.0)
    rspec-core (3.12.2)
      rspec-support (~> 3.12.0)
    rspec-expectations (3.12.3)
      diff-lcs (>= 1.2.0, < 2.0)
      rspec-support (~> 3.12.0)
    rspec-mocks (3.12.6)
      diff-lcs (>= 1.2.0, < 2.0)
      rspec-support (~> 3.12.0)
    rspec-support (3.12.1)

PLATFORMS
  arm64-darwin-23

DEPENDENCIES
  prop_check (~> 0.18.1)
  rspec (~> 3.12)

CHECKSUMS
  amazing_print (1.5.0) sha256=f9f411b37257333a0f0cc16ce6520b2217a6f0b5a9f35656e1d403cd5e0c3362
  diff-lcs (1.5.0) sha256=49b934001c8c6aedb37ba19daec5c634da27b318a7a3c654ae979d6ba1929b67
  prop_check (0.18.1) sha256=b1e1d4bf53bbd72f31d889835277ef6edcdfdbf0dc06861cb81107539567ba1d
  rspec (3.12.0) sha256=ccc41799a43509dc0be84070e3f0410ac95cbd480ae7b6c245543eb64162399c
  rspec-core (3.12.2) sha256=155b54480f28e2b2813185077fe435c2d663031616360ed3b179a9d6a55d2551
  rspec-expectations (3.12.3) sha256=093d18e2e7e0a2c619ef8f7343d442fc6c0793fb7897d56f16f26c8a9d244416
  rspec-mocks (3.12.6) sha256=de51a4148ba2ce6f1c1646a2a03e9df2f52da9a42b164f2e7467b2cbe37e07bf
  rspec-support (3.12.1) sha256=f969b85d0068ff97bc47c9d6fc2bca9706d73406f2b4e5d3b346443d8734c8cf

BUNDLED WITH
   2.5.0.dev

naive_average.rb

# 全ての要素が整数の、要素を 1 つ以上持つ配列を引数にとり、その要素の合計を要素数で割った平均を整数で返す
def naive_average(array)
  array.sum / array.length
end

naive_average_spec.rb

require 'naive_average'
require 'prop_check'
require 'rspec'

RSpec.describe "#naive_average" do
  G = PropCheck::Generators

  it "returns an integer for any input except empty array" do
    PropCheck.forall(G.array(G.integer, empty: false)) do |numbers|
      result = naive_average(numbers)

      expect(result).to be_a(Integer)
    end
  end
end