From 1488e2ca88c86eee98302e545f937e9a76db2a58 Mon Sep 17 00:00:00 2001
From: Owen Stephens <owen@owenstephens.co.uk>
Date: Sun, 19 Jun 2016 14:28:44 +0100
Subject: [PATCH] [Fix #3058] Add space inside percent literal style cops
 (#3214)

Add `Style/SpaceInsideArrayPercentLiteral` and
`Style/SpaceInsidePercentLiteralDelimiters`
---
 CHANGELOG.md                                  |   2 +
 config/enabled.yml                            |   8 ++
 lib/rubocop.rb                                |   3 +
 lib/rubocop/cop/mixin/match_range.rb          |  26 +++++
 lib/rubocop/cop/mixin/percent_literal.rb      |  10 ++
 .../space_inside_array_percent_literal.rb     |  53 ++++++++++
 ...space_inside_percent_literal_delimiters.rb |  64 +++++++++++
 ...space_inside_array_percent_literal_spec.rb |  86 +++++++++++++++
 ..._inside_percent_literal_delimiters_spec.rb | 100 ++++++++++++++++++
 9 files changed, 352 insertions(+)
 create mode 100644 lib/rubocop/cop/mixin/match_range.rb
 create mode 100644 lib/rubocop/cop/style/space_inside_array_percent_literal.rb
 create mode 100644 lib/rubocop/cop/style/space_inside_percent_literal_delimiters.rb
 create mode 100644 spec/rubocop/cop/style/space_inside_array_percent_literal_spec.rb
 create mode 100644 spec/rubocop/cop/style/space_inside_percent_literal_delimiters_spec.rb

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8e8c11a83c19..1ca8596d6719 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,6 +14,8 @@
 * [#3173](https://github.com/bbatsov/rubocop/pull/3173): Make `Style/ModuleFunction` configurable with `module_function` and `extend_self` styles. ([@tjwp][])
 * [#3105](https://github.com/bbatsov/rubocop/issues/3105): Add new `Style/RequestReferer` cop. ([@giannileggio][])
 * [#3200](https://github.com/bbatsov/rubocop/pull/3200): Add autocorrect for `Style/EachForSimpleLoop` cop. ([@tejasbubane][])
+* [#3058](https://github.com/bbatsov/rubocop/issues/3058): Add new `Style/SpaceInsideArrayPercentLiteral` cop. ([@owst][])
+* [#3058](https://github.com/bbatsov/rubocop/issues/3058): Add new `Style/SpaceInsidePercentLiteralDelimiters` cop. ([@owst][])
 * [#3179](https://github.com/bbatsov/rubocop/pull/3179): Expose files to support testings Cops using RSpec. ([@tjwp][])
 * [#3191](https://github.com/bbatsov/rubocop/issues/3191): Allow arbitrary comments after cop names in CommentConfig lines (e.g. rubocop:enable). ([@owst][])
 * [#3177](https://github.com/bbatsov/rubocop/pull/3177): Add new `Style/NumericLiteralPrefix` cop. ([@tejasbubane][])
diff --git a/config/enabled.yml b/config/enabled.yml
index e990f287dea0..6abf98cd6b63 100644
--- a/config/enabled.yml
+++ b/config/enabled.yml
@@ -760,6 +760,14 @@ Style/SpaceAroundOperators:
   StyleGuide: 'https://github.com/bbatsov/ruby-style-guide#spaces-operators'
   Enabled: true
 
+Style/SpaceInsideArrayPercentLiteral:
+  Description: 'No unnecessary additional spaces between elements in %i/%w literals.'
+  Enabled: true
+
+Style/SpaceInsidePercentLiteralDelimiters:
+  Description: 'No unnecessary spaces inside delimiters of %i/%w/%x literals.'
+  Enabled: true
+
 Style/SpaceInsideBrackets:
   Description: 'No spaces after [ or before ].'
   StyleGuide: 'https://github.com/bbatsov/ruby-style-guide#no-spaces-braces'
diff --git a/lib/rubocop.rb b/lib/rubocop.rb
index 4167967c78ae..d549385a86b7 100644
--- a/lib/rubocop.rb
+++ b/lib/rubocop.rb
@@ -64,6 +64,7 @@
 require 'rubocop/cop/mixin/if_node'
 require 'rubocop/cop/mixin/integer_node'
 require 'rubocop/cop/mixin/on_method_def'
+require 'rubocop/cop/mixin/match_range'
 require 'rubocop/cop/mixin/method_complexity' # relies on on_method_def
 require 'rubocop/cop/mixin/method_preference'
 require 'rubocop/cop/mixin/min_body_length'
@@ -329,10 +330,12 @@
 require 'rubocop/cop/style/space_before_comment'
 require 'rubocop/cop/style/space_before_first_arg'
 require 'rubocop/cop/style/space_before_semicolon'
+require 'rubocop/cop/style/space_inside_array_percent_literal'
 require 'rubocop/cop/style/space_inside_block_braces'
 require 'rubocop/cop/style/space_inside_brackets'
 require 'rubocop/cop/style/space_inside_hash_literal_braces'
 require 'rubocop/cop/style/space_inside_parens'
+require 'rubocop/cop/style/space_inside_percent_literal_delimiters'
 require 'rubocop/cop/style/space_inside_range_literal'
 require 'rubocop/cop/style/space_inside_string_interpolation'
 require 'rubocop/cop/style/special_global_vars'
diff --git a/lib/rubocop/cop/mixin/match_range.rb b/lib/rubocop/cop/mixin/match_range.rb
new file mode 100644
index 000000000000..cf3b89da0a52
--- /dev/null
+++ b/lib/rubocop/cop/mixin/match_range.rb
@@ -0,0 +1,26 @@
+# encoding: utf-8
+# frozen_string_literal: true
+
+module RuboCop
+  module Cop
+    # Common functionality for obtaining source ranges from regexp matches
+    module MatchRange
+      # Return a new `Range` covering the first matching group number for each
+      # match of `regex` inside `range`
+      def each_match_range(range, regex)
+        range.source.scan(regex) do
+          yield match_range(range, Regexp.last_match)
+        end
+      end
+
+      # For a `match` inside `range`, return a new `Range` covering the match
+      def match_range(range, match)
+        Parser::Source::Range.new(
+          range.source_buffer,
+          range.begin_pos + match.begin(1),
+          range.begin_pos + match.end(1)
+        )
+      end
+    end
+  end
+end
diff --git a/lib/rubocop/cop/mixin/percent_literal.rb b/lib/rubocop/cop/mixin/percent_literal.rb
index ac0a4b6c416d..fe45e8742017 100644
--- a/lib/rubocop/cop/mixin/percent_literal.rb
+++ b/lib/rubocop/cop/mixin/percent_literal.rb
@@ -22,6 +22,16 @@ def begin_source(node)
       def type(node)
         node.loc.begin.source[0..-2]
       end
+
+      # A range containing only the contents of the percent literal (e.g. in
+      # %i{1 2 3} this will be the range covering '1 2 3' only)
+      def contents_range(node)
+        Parser::Source::Range.new(
+          node.loc.expression.source_buffer,
+          node.loc.begin.end_pos,
+          node.loc.end.begin_pos
+        )
+      end
     end
   end
 end
diff --git a/lib/rubocop/cop/style/space_inside_array_percent_literal.rb b/lib/rubocop/cop/style/space_inside_array_percent_literal.rb
new file mode 100644
index 000000000000..24f5f99c43b0
--- /dev/null
+++ b/lib/rubocop/cop/style/space_inside_array_percent_literal.rb
@@ -0,0 +1,53 @@
+# encoding: utf-8
+# frozen_string_literal: true
+
+module RuboCop
+  module Cop
+    module Style
+      # Checks for unnecessary additional spaces inside array percent literals
+      # (i.e. %i/%w).
+      #
+      # @good
+      # %i(foo bar baz)
+      #
+      # @bad
+      # %w(foo  bar  baz)
+      class SpaceInsideArrayPercentLiteral < Cop
+        include MatchRange
+        include PercentLiteral
+
+        MSG = 'Use only a single space inside array percent literal.'.freeze
+        MULTIPLE_SPACES_BETWEEN_ITEMS_REGEX =
+          /(?:[\S&&[^\\]](?:\\ )*)( {2,})(?=\S)/
+
+        def on_array(node)
+          process(node, *%w(%i %I %w %W))
+        end
+
+        def on_percent_literal(node)
+          each_unnecessary_space_match(node) do |range|
+            add_offense(node, range, MSG)
+          end
+        end
+
+        def autocorrect(node)
+          lambda do |corrector|
+            each_unnecessary_space_match(node) do |range|
+              corrector.replace(range, ' ')
+            end
+          end
+        end
+
+        private
+
+        def each_unnecessary_space_match(node, &blk)
+          each_match_range(
+            contents_range(node),
+            MULTIPLE_SPACES_BETWEEN_ITEMS_REGEX,
+            &blk
+          )
+        end
+      end
+    end
+  end
+end
diff --git a/lib/rubocop/cop/style/space_inside_percent_literal_delimiters.rb b/lib/rubocop/cop/style/space_inside_percent_literal_delimiters.rb
new file mode 100644
index 000000000000..ffe992b4f867
--- /dev/null
+++ b/lib/rubocop/cop/style/space_inside_percent_literal_delimiters.rb
@@ -0,0 +1,64 @@
+# encoding: utf-8
+# frozen_string_literal: true
+
+module RuboCop
+  module Cop
+    module Style
+      # Checks for unnecessary additional spaces inside the delimiters of
+      # %i/%w/%x literals.
+      #
+      # @good
+      # %i(foo bar baz)
+      #
+      # @bad
+      # %w( foo bar baz )
+      #
+      # @bad
+      # %x(  ls -l )
+      class SpaceInsidePercentLiteralDelimiters < Cop
+        include MatchRange
+        include PercentLiteral
+
+        MSG = 'Do not use spaces inside percent literal delimiters.'.freeze
+        BEGIN_REGEX = /\A( +)/
+        END_REGEX = /(?<!\\)( +)\z/
+
+        def on_array(node)
+          process(node, *%w(%i %I %w %W))
+        end
+
+        def on_percent_literal(node)
+          add_offenses_for_unnecessary_spaces(node)
+        end
+
+        def on_xstr(node)
+          add_offenses_for_unnecessary_spaces(node)
+        end
+
+        def autocorrect(node)
+          lambda do |corrector|
+            regex_matches(node) do |match_range|
+              corrector.remove(match_range)
+            end
+          end
+        end
+
+        private
+
+        def add_offenses_for_unnecessary_spaces(node)
+          return unless node.single_line?
+
+          regex_matches(node) do |match_range|
+            add_offense(node, match_range, MSG)
+          end
+        end
+
+        def regex_matches(node, &blk)
+          [BEGIN_REGEX, END_REGEX].each do |regex|
+            each_match_range(contents_range(node), regex, &blk)
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/spec/rubocop/cop/style/space_inside_array_percent_literal_spec.rb b/spec/rubocop/cop/style/space_inside_array_percent_literal_spec.rb
new file mode 100644
index 000000000000..3dcfe74744b5
--- /dev/null
+++ b/spec/rubocop/cop/style/space_inside_array_percent_literal_spec.rb
@@ -0,0 +1,86 @@
+# encoding: utf-8
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe RuboCop::Cop::Style::SpaceInsideArrayPercentLiteral do
+  subject(:cop) { described_class.new }
+
+  %w(i I w W).each do |type|
+    [%w({ }), %w{( )}, %w([ ]), %w(! !)].each do |(ldelim, rdelim)|
+      context "for #{type} type and #{[ldelim, rdelim]} delimiters" do
+        define_method(:example) do |content|
+          ['%', type, ldelim, content, rdelim].join
+        end
+
+        def expect_corrected(source, expected)
+          expect(autocorrect_source(cop, source)).to eq expected
+        end
+
+        it 'registers an offense for unnecessary spaces' do
+          source = example('1   2')
+          inspect_source(cop, source)
+          expect(cop.offenses.size).to eq(1)
+          expect(cop.highlights).to eq(['   '])
+          expect(cop.messages).to eq([described_class::MSG])
+          expect_corrected(source, example('1 2'))
+        end
+
+        it 'registers an offense for multiple spaces between items' do
+          source = example('1   2   3')
+          inspect_source(cop, source)
+          expect(cop.offenses.size).to eq(2)
+          expect_corrected(source, example('1 2 3'))
+        end
+
+        it 'accepts literals with escaped and additional spaces' do
+          source = example('a\   b \ c')
+          inspect_source(cop, source)
+          expect(cop.offenses.size).to eq(1)
+          expect_corrected(source, example('a\  b \ c'))
+        end
+
+        it 'accepts literals without additional spaces' do
+          inspect_source(cop, example('a b c'))
+          expect(cop.messages).to be_empty
+        end
+
+        it 'accepts literals with escaped spaces' do
+          inspect_source(cop, example('a\  b\ \  c'))
+          expect(cop.messages).to be_empty
+        end
+
+        it 'accepts multi-line literals' do
+          inspect_source(cop, ["%#{type}(",
+                               '  a',
+                               '  b',
+                               '  c',
+                               ')'])
+          expect(cop.messages).to be_empty
+        end
+
+        it 'accepts multi-line literals within a method' do
+          inspect_source(cop, ['def foo',
+                               "  %#{type}(",
+                               '    a',
+                               '    b',
+                               '    c',
+                               '  )',
+                               'end'])
+          expect(cop.messages).to be_empty
+        end
+
+        it 'accepts newlines and additional following alignment spaces' do
+          inspect_source(cop, ["%#{type}(a b",
+                               '   c)'])
+          expect(cop.messages).to be_empty
+        end
+      end
+    end
+  end
+
+  it 'accepts non array percent literals' do
+    inspect_source(cop, '%q( a  b c )')
+    expect(cop.messages).to be_empty
+  end
+end
diff --git a/spec/rubocop/cop/style/space_inside_percent_literal_delimiters_spec.rb b/spec/rubocop/cop/style/space_inside_percent_literal_delimiters_spec.rb
new file mode 100644
index 000000000000..8275c7b6c087
--- /dev/null
+++ b/spec/rubocop/cop/style/space_inside_percent_literal_delimiters_spec.rb
@@ -0,0 +1,100 @@
+# encoding: utf-8
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe RuboCop::Cop::Style::SpaceInsidePercentLiteralDelimiters do
+  subject(:cop) { described_class.new }
+
+  %w(i I w W x).each do |type|
+    [%w({ }), %w{( )}, %w([ ]), %w(! !)].each do |(ldelim, rdelim)|
+      context "for #{type} type and #{[ldelim, rdelim]} delimiters" do
+        define_method(:example) do |content|
+          ['%', type, ldelim, content, rdelim].join
+        end
+
+        def expect_corrected(source, expected)
+          expect(autocorrect_source(cop, source)).to eq expected
+        end
+
+        it 'registers an offense for unnecessary spaces' do
+          source = example(' 1 2  ')
+          inspect_source(cop, source)
+          expect(cop.offenses.size).to eq(2)
+          expect(cop.messages.uniq).to eq([described_class::MSG])
+          expect(cop.highlights).to eq([' ', '  '])
+          expect_corrected(source, example('1 2'))
+        end
+
+        it 'registers an offense for spaces after first delimiter' do
+          source = example(' 1 2')
+          inspect_source(cop, source)
+          expect(cop.offenses.size).to eq(1)
+          expect_corrected(source, example('1 2'))
+        end
+
+        it 'registers an offense for spaces before final delimiter' do
+          source = example('1 2 ')
+          inspect_source(cop, source)
+          expect(cop.offenses.size).to eq(1)
+          expect_corrected(source, example('1 2'))
+        end
+
+        it 'registers an offense for literals with escaped and other spaces' do
+          source = example(' \ a b c\  ')
+          inspect_source(cop, source)
+          expect(cop.offenses.size).to eq(2)
+          expect_corrected(source, example('\ a b c\ '))
+        end
+
+        it 'accepts literals without additional spaces' do
+          inspect_source(cop, example('a b c'))
+          expect(cop.messages).to be_empty
+        end
+
+        it 'accepts literals with escaped spaces' do
+          inspect_source(cop, example('\ a b c\ '))
+          expect(cop.messages).to be_empty
+        end
+
+        it 'accepts multi-line literals' do
+          inspect_source(cop, ["%#{type}(",
+                               '  a',
+                               '  b',
+                               '  c',
+                               ')'])
+          expect(cop.messages).to be_empty
+        end
+
+        it 'accepts multi-line literals within a method' do
+          inspect_source(cop, ['def foo',
+                               "  %#{type}(",
+                               '    a',
+                               '    b',
+                               '    c',
+                               '  )',
+                               'end'])
+          expect(cop.messages).to be_empty
+        end
+
+        it 'accepts newlines and additional following alignment spaces' do
+          inspect_source(cop, ["%#{type}(a b",
+                               '   c)'])
+          expect(cop.messages).to be_empty
+        end
+
+        it 'accepts spaces between entries' do
+          inspect_source(cop, example('a  b  c'))
+          expect(cop.messages).to be_empty
+        end
+      end
+    end
+  end
+
+  it 'accepts other percent literals' do
+    %w(q r s).each do |type|
+      inspect_source(cop, "%#{type}( a  b c )")
+      expect(cop.messages).to be_empty
+    end
+  end
+end