Allow underscore for method name with receiver

[pocke]

Problem

_ matcher with method chain raises a syntax error.

example

rules:
  - id: sample.abc
    pattern:
      - b._
    message: a
    examples:
      - before: 'b.c'
        after: 'b'

m

$ querly test
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/parser-2.6.2.0/lib/parser/lexer.rb:10861: warning: assigned but unused variable - testEof
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/querly-0.15.1/lib/querly/node_pair.rb:28: warning: `&' interpreted as argument prefix
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/querly-0.15.1/lib/querly/pattern/parser.rb:825: warning: mismatched indentations at 'end' with 'module' at 9
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/querly-0.15.1/lib/querly/pattern/parser.rb:826: warning: mismatched indentations at 'end' with 'module' at 8
Fatal error:
#<Querly::Rule::PatternSyntaxError: Pattern syntax error: rule=sample.abc, index=0, pattern=b._, where={}: 
parse error on value "_" (UNDERBAR)>
  /home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/querly-0.15.1/lib/querly/rule.rb:86:in `rescue in block in load'
  /home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/querly-0.15.1/lib/querly/rule.rb:83:in `block in load'
  /home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/querly-0.15.1/lib/querly/rule.rb:73:in `map'
  /home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/querly-0.15.1/lib/querly/rule.rb:73:in `with_index'
  /home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/querly-0.15.1/lib/querly/rule.rb:73:in `load'
  /home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/querly-0.15.1/lib/querly/config.rb:62:in `block in config'
  /home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/querly-0.15.1/lib/querly/config.rb:62:in `map'
  /home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/querly-0.15.1/lib/querly/config.rb:62:in `config'
  /home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/querly-0.15.1/lib/querly/config.rb:18:in `load'
  /home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/querly-0.15.1/lib/querly/cli/test.rb:156:in `load_config'
  /home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/querly-0.15.1/lib/querly/cli/test.rb:24:in `run'
  /home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/querly-0.15.1/lib/querly/cli.rb:100:in `test'
  /home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/thor-0.20.3/lib/thor/command.rb:27:in `run'
  /home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/thor-0.20.3/lib/thor/invocation.rb:126:in `invoke_command'
  /home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/thor-0.20.3/lib/thor.rb:387:in `dispatch'
  /home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/thor-0.20.3/lib/thor/base.rb:466:in `start'
  /home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/querly-0.15.1/exe/querly:8:in `<top (required)>'
  /home/pocke/.rbenv/versions/trunk/bin/querly:23:in `load'
  /home/pocke/.rbenv/versions/trunk/bin/querly:23:in `<main>'

I think it is useful if it allows _ in method chain.

link: https://mobile.twitter.com/hanachin_/status/1113674668815159297

Goal

• Allow _ in method chain, without args, without block. It means it supports only most simple case.
• Support more syntax
  • like foo._(arg), block, etc
• Add test

---

cc: @hanachin

[pocke]

These patterns are completely duplicated.

[soutaro]

Looks great! I had worried about the pattern to match _ method calls but finally discovered there is no real problem; Querly has not supported it at all! 😄

Do you have any idea for this conflict?

[pocke]

I guess we can use the meta (') and where features to detect actual _ method call. It looks a workaround, but it is a rare case.