Enjoy Ruby Programming in IDE and TypeProf

RubyConf 2021

1. Enjoy Ruby Programming in IDE and TypeProf Yusuke Endoh (@mametter) RubyConf 2021
2. Yusuke Endoh / @mametter •A Ruby committer working at Cookpad w/ @ko1 •Main contribution so far: • Designed and implemented keyword arguments • Implemented test coverage feature • Implementing TypeProf  Today's topic 2
3. A recent contribution: error_highlight 3 json = { foo: { bar: { baz: 42 } } } json[:foo][:barr][:baz] # Ruby 3.0 $ ruby t.rb t.rb:2:in `<main>': undefined method `[]' for nil:NilClass (NoMethodError) # Ruby 3.1 $ ruby t.rb t.rb:2:in `<main>': undefined method `[]' for nil:NilClass (NoMethodError) json[:foo][:barr][:baz] ^^^^^^ Credit: The original author of its prototype is @yui-knk https://github.com/ruby/ruby/pull/4470
4. Index •What is TypeProf? •TypeProf for IDE • How to use TypeProf for IDE • Conclusion 4
5. TypeProf: A static analyzer for Ruby 3 •TypeProf analyzes non-annotated Ruby code • guess types of method arguments and a return value 5 class User def initialize(name) @name = name end end User.new("John") Ruby code class User def initialize:(String name)->void end RBS TypeProf
6. TypeProf? RBS? Steep? Sorbet? 6 Name What RBS TypeProf Steep Sorbet The Ruby official type definition language A static type analyzer for Ruby A static type analyzer for Ruby A static type analyzer for Ruby
7. Comparison between static analyzers 7 TypeProf Steep Sorbet Type inference Strong Weak Weak Accuracy Weak Strong Strong Analysis speed Slow Fast Very fast RBS support Yes Yes Not yet IDE support No → Yes Yes Yes
8. RBS: An official language for Ruby types • Common complaint: "Header files suck" • TypeProf for IDE may solve this issue 8 class User def initialize(name) @name = name end end User.new("John") user.rb class User def initialize: (String name) -> void end user.rbs
9. Index •What is TypeProf? •TypeProf for IDE • How to use TypeProf for IDE • Conclusion 9
10. Today's topic: TypeProf for IDE 10 VSCode TypeProf code changed error found complete "5.ti" maybe "5.times" 5.ti| Do you mean: 5.times 1 + "str" 1 + "str" Is this a bug? • A VSCode extension for Ruby powered by TypeProf
11. Demo: TypeProf for IDE 11
12. The modern development experience with TypeProf for IDE 12 On-the-fly method signature
13. The modern development experience with TypeProf for IDE 13 On-the-fly error reporting
14. The modern development experience with TypeProf for IDE 14
15. The modern development experience with TypeProf for IDE 15 On-the-fly type inference Completion
16. The modern development experience with TypeProf for IDE 16 Hint for arguments
17. Demo: Summary •Modern development experience comes to Ruby without type annotations •RBS are interspersed to Ruby files • One possible answer to "Header files suck" 17
18. Index •What is TypeProf? •TypeProf for IDE • How to use TypeProf for IDE • Conclusion 18
19. How to configure TypeProf for IDE • Use ruby 3.1.0-dev (development version☺) • Add for your Gemfile • Configure RBS collection • if you use gems • Install VSCode extension→ • search "typeprof" • Open your folder with VSCode and pray • More detail: https://github.com/ruby/typeprof/blob/master/doc/ide.md 19 gem "typeprof"
20. Protips™ •Write a simple test in a file •Write RBS 😞 20
21. Demo: Tests instead of type annotations 21 untyped String
22. Demo: Passing an unknown type 22 The method signature is changed to accept a new type Error in the callee side
23. Demo: Manual RBS specification 23 Click here A prototype RBS is created
24. Demo: Manual RBS specification (cont'd) 24 Error in the caller side # means RBS-defined
25. Protips™ •Write a simple test in a file • TypeProf requires a test to guess method signatures •Write RBS to fix method signatures (if needed) • This makes TypeProf analysis faster • This is also useful to make TypeProf faster 25
26. Index •What is TypeProf? •TypeProf for IDE • How to use TypeProf for IDE • Conclusion 26
27. Release plan •TypeProf for IDE will be released in Ruby 3.1 • Happy if you could play with it and give us feedback •Ready for production? • Experimental, but hopefully works for small programs • For large code base, please write RBS for gems first! • https://github.com/ruby/gem_rbs_collection 27
28. Special thanks •Hideki Miura • Ruby committers: matz, akr, ko1, soutaro • Katsuhiro Ueno & Eijiro Sumii •Stripe team & Shopify team & Jeff Foster • Yuta Saito (@kateinoigakukun) • Many improvements of TypeProf for IDE 28
29. Conclusion •The modern development experience is possible without full type annotations by TypeProf for IDE •Ruby 3.1 will bundle TypeProf for IDE 29