Fix - Simple, stupid testing framework for Ruby

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Fix Simple, stupid testing framework for Ruby March 1, 2016

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github.com/cyril Cyril Kato twitter.com/cyri_

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Chess Gungi Shogi Xiangqi

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Let’s begin with a survey...

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Who likes RSpec?

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No content

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Even for simple code?

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Even for simple code? Let’s take an example

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0-example/app.rb APP = 42

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0-example/app_spec.rb require_relative 'app' require 'rspec' RSpec.describe APP do it { expect(described_class).to be 42 } end

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0-example/app_small_test.rb require_relative 'app' fail unless 42.equal?(APP)

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Both tests are passing: ➜ ruby 0-example/app_small_test.rb ➜ rspec 0-example/app_spec.rb . Finished in 0.00098 seconds 1 example, 0 failures

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Both tests are passing. But...

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Testing with RSpec, the result was processed over... rspec 3.4.0 63 LOC

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Testing with RSpec, the result was processed over... rspec 3.4.0 rspec-core 3.4.3 63 LOC 7 389 LOC +

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Testing with RSpec, the result was processed over... rspec 3.4.0 rspec-core 3.4.3 rspec-expectations 3.4.0 63 LOC 7 389 LOC 3 917 LOC + +

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Testing with RSpec, the result was processed over... rspec 3.4.0 rspec-core 3.4.3 rspec-expectations 3.4.0 rspec-mocks 3.4.1 63 LOC 7 389 LOC 3 917 LOC 4 106 LOC + + +

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Testing with RSpec, the result was processed over... rspec 3.4.0 rspec-core 3.4.3 rspec-expectations 3.4.0 rspec-mocks 3.4.1 rspec-support 3.4.1 63 LOC 7 389 LOC 3 917 LOC 4 106 LOC 1 624 LOC + + + +

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Testing with RSpec, the result was processed over... rspec 3.4.0 rspec-core 3.4.3 rspec-expectations 3.4.0 rspec-mocks 3.4.1 rspec-support 3.4.1 diff-lcs 1.2.5 63 LOC 7 389 LOC 3 917 LOC 4 106 LOC 1 624 LOC 1 405 LOC + + + + +

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In the other case, with Ruby’s fail(*args)

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1 LOC

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Both tests are passing. Butthe second is more relevant.

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complexity(testing tool) SHOULD be < complexity(code)

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Code to test Testing tool

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BTW

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No content

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ANYWAY Here’s another example

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require 'rspec' RSpec.describe(-42) do describe '#abs' do it { expect(described_class.abs).to equal 42 } end end

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require 'rspec' RSpec.describe(-42) do describe '#abs' do it { expect(described_class.abs).to equal 42 } end end Same method, but different behavior

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require 'rspec' RSpec.describe(-42) do describe '#abs' do it { expect(described_class.abs).to equal 42 } end end I don’t care about class or instance methods

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require 'rspec' RSpec.describe(-42) do describe '#abs' do it { expect(described_class.abs).to equal 42 } end end We need to repeat the code

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ZOMG FIX new specing framework

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require 'fix' Fix.describe(-42) do on :abs do it { MUST equal 42 } end end

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require 'fix' Fix.describe(-42) do on :abs do it { MUST equal 42 } end end The front object

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require 'fix' Fix.describe(-42) do on :abs do it { MUST equal 42 } end end An event

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require 'fix' Fix.describe(-42) do on :abs do it { MUST equal 42 } end end A subject

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require 'fix' Fix.describe(-42) do on :abs do it { MUST equal 42 } end end An absolute requirement

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RFC 2119 compliant

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The key words "MUST", "MUST NOT", "SHOULD", "SHOULD NOT", and "MAY" in this document are to be interpreted as described in RFC 2119.

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What about code isolation

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require 'rspec' greeting = 'Hello world!' RSpec.describe greeting do context 'Alice' do before { greeting.gsub!('world', 'Alice') } it { expect(greeting).to eql 'Hello Alice!' } end context 'Bob' do before { greeting.gsub!('world', 'Bob') } it { expect(greeting).to eql 'Hello Bob!' } end end

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➜ rspec 2-example/greeting_spec.rb .F Failures: 1) Hello world! Bob should eql "Hello Bob!" Failure/Error: it { expect(greeting).to eql 'Hello Bob!' } expected: "Hello Bob!" got: "Hello Alice!" Finished in 0.01521 seconds 2 examples, 1 failure

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require 'fix' greeting = 'Hello world!' Fix.describe greeting do context 'Alice' do on :gsub!, 'world', 'Alice' do it { MUST eql 'Hello Alice!' } end end context 'Bob' do on :gsub!, 'world', 'Bob' do it { MUST eql 'Hello Bob!' } end end end

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➜ ruby 2-example/greeting_fix.rb .. Ran 2 tests in 0.005775 seconds 100% compliant - 0 infos, 0 failures, 0 errors

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With Fix, no side effects outside contexts

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no particular Style Guide

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Don't make me think

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describe "#foo" or describe ".foo"?

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describe or context?

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it or specify?

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Don't get me wrong

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No content

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So I decided to rebuild it

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In a more adequat way

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github.com/cyril/r_spec and I call it r_spec

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No content

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Well, let’s try it!

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app = 'OMGLOL' def app.equal?(*) true end require 'rspec' RSpec.describe app do it { expect(app).to be 42 } end

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app = 'OMGLOL' def app.equal?(*) true end require 'rspec' RSpec.describe app do it { expect(app).to be 42 } end rspec 3-example/strange_app_spec.rb . Finished in 0.00097 seconds 1 example, 0 failures

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What did you RSpec?

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app = 'OMGLOL' def app.equal?(*) true end require 'rspec' RSpec.describe app do it { expect(app).to be 42 } end rspec 3-example/strange_app_spec.rb . Finished in 0.00097 seconds 1 example, 0 failures

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app = 'OMGLOL' def app.equal?(*) true end require 'rspec' RSpec.describe app do it { expect(app).to be 42 } end rspec 3-example/strange_app_spec.rb . Finished in 0.00097 seconds 1 example, 0 failures Let’s fix that!

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app = 'OMGLOL' def app.equal?(*) true end require 'rspec' RSpec.describe app do it { expect(app).to be 42 } end

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app = 'OMGLOL' def app.equal?(*) true end require 'r_spec' RSpec.describe app do it { expect(app).to be 42 } end

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app = 'OMGLOL' def app.equal?(*) true end require 'r_spec' RSpec.describe app do it { expect(app).to be 42 } end rspec 3-example/strange_app_spec.rb F 1. Failure: Expected "OMGLOL" to be 42. /Users/cyril/parisrb/3-example/strange_ app_spec.rb:10:in `block (2 levels) in ' Ran 1 tests in 0.000195 seconds 0% compliant - 0 infos, 1 failures, 0 errors