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Road to RuboCop 1.0
Koichi ITO
September 04, 2020
Programming
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Road to RuboCop 1.0
RubyKaigi Takeout 2020 Day1
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https://www.youtube.com/watch?v=jkY7J9k6mHs&feature=emb_logo
Koichi ITO
September 04, 2020
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Transcript
Road to RuboCop 1.0 ,PJDIJ*50&4. *OD 3VCZ,BJHJ5BLFPVU Ride on RuboCop
1.0 for safe static analysis
!LPJD w 3VCP$PQDPSFUFBN w 044QSPHSBNNFS w 5FDITQFBLFS w %JTUJOHVJTIFE&OHJOFFSBU &4.
*OD
&4. *OD
Support OSS community
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#VOEMFS 1SZ 34QFD 3VCP$PQ CZFCVH 3VCZ,BJHJ %3&$0.CPPUI
None
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3VCP$PQDPSFEFWFMPQFST +0900 UTC+0200 +0300 +0800 -0400 "VUIPS .PSFUIBODPOUSJCVUPSTJOZFBST
3VCP$PQDPSFEFWFMPQFST +0900 UTC+0200 +0300 +0800 -0400 .F .PSFUIBODPOUSJCVUPSTJOZFBST
3VCP$PQ"SDIJUFDUVSF
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+VBOJUP'BUBTGBTUSVCZSFQP
SBJMTSBJMT
#FODINBSLJQT require 'benchmark/ips' SLUG = 'writing-fast-ruby' def slow SLUG.gsub('-', '
') end def fast SLUG.tr('-', ' ') end Benchmark.ips do |x| x.report('String#gsub') { slow } x.report('String#tr') { fast } x.compare! end % ruby -v gsub-vs-tr.rb ruby 2.7.1p83 (2020-03-31 revision a0c7c23c9c) [x86_64-darwin17] Warming up -------------------------------------- String#gsub 59.463k i/100ms String#tr 296.069k i/100ms Calculating ------------------------------------- String#gsub 598.537k (± 1.8%) i/s - 3.033M in 5.068466s String#tr 2.955M (± 0.9%) i/s - 14.803M in 5.009464s Comparison: String#tr: 2955357.8 i/s String#gsub: 598537.4 i/s - 4.94x (± 0.00) slower
w 3VCP$PQDPSFGPDVTPOQMBUGPSN JOEFQFOEFOU3VCZQFSGPSNBODF w 1FSGPSNBODFDPQGPDVTPO.3*`T QFSGPSNBODF w 5IFpSTUFYUSBDUFEHFN 3VCP$PQ (FNJGZOPUFT
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w*BTLFE!BNBUTVEB IPX,BNJOBSJEJWJEFE SFOEFSJOHFOHJOFT )PXXBTUIFSFQPTJUPSZLFQUIJTUPSZ
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git remote add upstream-performance \ <rubocop-performance URL> % git pull upstream-performance
MPDBM SFNPUF(JU)VC 3VCP$PQ1FSGPSNBODF 'FUDIPSJHJOBMSFQP 3VCP$PQ1FSGPSNBODF 3VCP$PQ$PSF % git remote add
upstream-core \ <rubocop URL> % git fetch upstream-core
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cherry-pick 7cbfa5a <hash of core> % git cherry-pick 7cbfa5a % git cherry-pick ...
MPDBM # DONE! % git push origin master SFNPUF(JU)VC 1VTIOFXSFQP
3VCP$PQ1FSGPSNBODF 3VCP$PQ$PSF 3VCP$PQ1FSGPSNBODF
wPWFSDIFSSZQJDLT )PXNBOZDIFSSZQJDLT % git log --oneline lib/rubocop/cop/performance \ spec/rubocop/cop/performance |
wc -l 225 % git log --oneline lib/rubocop/cop/rails \ spec/rubocop/cop/rails | wc -l 315 *NOPUTVSFJUJTUIFCFTUPQUJPO
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3VCP$PQ"451SPDFTTFE4PVSDF require 'rubocop-ast' ast = RuboCop::AST::ProcessedSource.new( 'puts "hello"', 2.7 ).ast
#=>s(:send, nil, :puts, s(:str, "hello")) ast.class #=> RuboCop::AST::SendNode ast.send_type? #=> true ast.first_argument.basic_literal? #=> true
3VCP$PQ"455SBWFSTBM require 'rubocop-ast' include RuboCop::AST::Traversal # Event handler for `send`
node def on_send(node) 'hi' end walk(ast) #=> hi
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VersionChanged: '0.84' + SafeAutoCorrect: false
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A <= B
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&YBNQMFAOJMAWBSJBCMF # Performance/StartWith cop # bad str =~ /\Aab/ #
good str.start_with?('ab')
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&YBNQMFFYUFSOBMSFTPVSDFT # Rails/UniqBeforePluck cop # bad Model.pluck(:id).uniq # good Model.distinct.pluck(:id)
None
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