[Fix #4882] Use IndentationWidth of Layout/Tab for other cops

* Metrics/LineLength
* Style/IfUnlessModifier

CHANGELOG.md

@@ -30,6 +30,7 @@
 * [#5990](https://github.com/bbatsov/rubocop/pull/5990): Drop support for MRI 2.1. ([@drenmi][])
 * [#3299](https://github.com/bbatsov/rubocop/issues/3299): `Lint/UselessAccessModifier` now warns when `private_class_method` is used without arguments. ([@Darhazer][])
 * [#6026](https://github.com/rubocop-hq/rubocop/pull/6026): Exclude `refine` by default from `Metrics/BlockLength` cop. ([@kddeisz][])
+* [#4882](https://github.com/bbatsov/rubocop/issues/4882): Use `IndentationWidth` of `Layout/Tab` for other cops. ([@AlexWayfer][])
 
 ## 0.57.2 (2018-06-12)
 

lib/rubocop/cop/metrics/line_length.rb

@@ -7,6 +7,8 @@ module Cop
     module Metrics
       # This cop checks the length of lines in the source code.
       # The maximum length is configurable.
+      # The tab size is configured in the `IndentationWidth`
+      # of the `Layout/Tab` cop.
       class LineLength < Cop
         include ConfigurableMax
         include IgnoredPattern
@@ -23,8 +25,24 @@ def investigate(processed_source)
 
         private
 
+        def tab_indentation_width
+          config.for_cop('Layout/Tab')['IndentationWidth']
+        end
+
+        def line_length(line)
+          if tab_indentation_width
+            line = line.gsub("\t", ' ' * tab_indentation_width)
+          end
+          line.length
+        end
+
+        def highligh_start(line)
+          return max unless tab_indentation_width
+          max - (tab_indentation_width - 1) * line.count("\t")
+        end
+
         def check_line(line, index, heredocs)
-          return if line.length <= max
+          return if line_length(line) <= max
           return if ignored_line?(line, index, heredocs)
 
           if ignore_cop_directives? && directive_on_source_line?(index)
@@ -33,7 +51,10 @@ def check_line(line, index, heredocs)
           return check_uri_line(line, index) if allow_uri?
 
           register_offense(
-            source_range(processed_source.buffer, index + 1, 0...line.length),
+            source_range(
+              processed_source.buffer, index,
+              highligh_start(line)...line_length(line)
+            ),
             line
           )
         end
@@ -44,10 +65,10 @@ def ignored_line?(line, index, heredocs)
         end
 
         def register_offense(loc, line)
-          message = format(MSG, length: line.length, max: max)
+          message = format(MSG, length: line_length(line), max: max)
 
           add_offense(nil, location: loc, message: message) do
-            self.max = line.length
+            self.max = line_length(line)
           end
         end
 
@@ -59,7 +80,7 @@ def excess_range(uri_range, line, index)
                                end
 
           source_range(processed_source.buffer, index + 1,
-                       excessive_position...(line.length))
+                       excessive_position...(line_length(line)))
         end
 
         def max
@@ -100,7 +121,8 @@ def ignore_cop_directives?
 
         def allowed_uri_position?(line, uri_range)
           uri_range.begin < max &&
-            (uri_range.end == line.length || uri_range.end == line.length - 1)
+            (uri_range.end == line_length(line) ||
+             uri_range.end == line_length(line) - 1)
         end
 
         def find_excessive_uri_range(line)

lib/rubocop/cop/mixin/statement_modifier.rb

@@ -39,7 +39,7 @@ def modifier_fits_on_single_line?(node)
       end
 
       def length_in_modifier_form(node, cond, body_length)
-        indentation = node.loc.keyword.column
+        indentation = node.loc.keyword.column * indentation_multiplier
         kw_length = node.loc.keyword.size
         cond_length = cond.source_range.size
         space = 1
@@ -49,6 +49,11 @@ def length_in_modifier_form(node, cond, body_length)
       def max_line_length
         config.for_cop('Metrics/LineLength')['Max']
       end
+
+      def indentation_multiplier
+        return 1 if config.for_cop('Layout/Tab')['Enabled']
+        config.for_cop('Layout/Tab')['IndentationWidth']
+      end
     end
   end
 end

lib/rubocop/cop/style/if_unless_modifier.rb

@@ -5,7 +5,8 @@ module Cop
     module Style
       # Checks for if and unless statements that would fit on one line
       # if written as a modifier if/unless. The maximum line length is
-      # configured in the `Metrics/LineLength` cop.
+      # configured in the `Metrics/LineLength` cop. The tab size is configured
+      # in the `IndentationWidth` of the `Layout/Tab` cop.
       #
       # @example
       #   # bad

manual/cops_metrics.md

@@ -113,6 +113,8 @@ Enabled | No
 
 This cop checks the length of lines in the source code.
 The maximum length is configurable.
+The tab size is configured in the `IndentationWidth`
+of the `Layout/Tab` cop.
 
 ### Configurable attributes
 

manual/cops_style.md

@@ -2376,7 +2376,8 @@ Enabled | Yes
 
 Checks for if and unless statements that would fit on one line
 if written as a modifier if/unless. The maximum line length is
-configured in the `Metrics/LineLength` cop.
+configured in the `Metrics/LineLength` cop. The tab size is configured
+in the `IndentationWidth` of the `Layout/Tab` cop.
 
 ### Examples
 

spec/rubocop/cop/metrics/line_length_spec.rb

@@ -205,6 +205,13 @@ def test_some_other_long_test_description_which_exceeds_length
         inspect_source(source)
         expect(cop.offenses.size).to eq(1)
       end
+
+      it 'highlights excessive characters' do
+        inspect_source(source)
+        expect(cop.highlights).to eq(
+          ['061837309890f04ab08c']
+        )
+      end
     end
   end
 
@@ -334,4 +341,40 @@ def method_definition_that_is_just_under_the_line_length_limit(foo) # rubocop:di
       end
     end
   end
+
+  context 'affecting by IndentationWidth from Layout\Tab' do
+    let(:config) do
+      RuboCop::Config.new(
+        'Layout/IndentationWidth' => {
+          'Width' => 1
+        },
+        'Layout/Tab' => {
+          'Enabled' => false,
+          'IndentationWidth' => 2
+        },
+        'Metrics/LineLength' => {
+          'Max' => 80
+        }
+      )
+    end
+
+    it "registers an offense for a line that's including 1 tab with size 2" \
+       ' and 79 other characters' do
+      inspect_source("\t" + '#' * 79)
+      expect(cop.offenses.size).to eq(1)
+      expect(cop.offenses.first.message).to eq('Line is too long. [81/80]')
+      expect(cop.config_to_allow_offenses).to eq('Max' => 81)
+    end
+
+    it 'highlights excessive characters' do
+      inspect_source("\t" + '#' * 78 + 'abc')
+      expect(cop.highlights).to eq(['abc'])
+    end
+
+    it "accepts a line that's including 1 tab with size 2" \
+       ' and 78 other characters' do
+      inspect_source("\t" + '#' * 78)
+      expect(cop.offenses.empty?).to be(true)
+    end
+  end
 end

spec/rubocop/cop/style/if_unless_modifier_spec.rb

@@ -348,4 +348,62 @@
       RUBY
     end
   end
+
+  context 'with disabled Layout/Tab cop' do
+    let(:config) do
+      RuboCop::Config.new(
+        'Layout/IndentationWidth' => {
+          'Width' => 1
+        },
+        'Layout/Tab' => {
+          'Enabled' => false,
+          'IndentationWidth' => 2
+        },
+        'Metrics/LineLength' => { 'Max' => 80 }
+      )
+    end
+
+    context 'with tabs indentation' do
+      let(:source) do
+        # Empty lines should make no difference.
+        <<-RUBY
+						if #{condition}
+							#{body}
+						end
+        RUBY
+      end
+
+      let(:body) { 'b' * 38 }
+
+      context 'it fits on one line' do
+        let(:condition) { 'a' * 26 }
+
+        it 'registers an offense' do
+          # This if statement fits exactly on one line if written as a
+          # modifier.
+          expect("#{body} if #{condition}".length).to eq(68)
+
+          inspect_source(source)
+          expect(cop.messages).to eq(
+            ['Favor modifier `if` usage when having a single-line' \
+             ' body. Another good alternative is the usage of control flow' \
+             ' `&&`/`||`.']
+          )
+        end
+      end
+
+      context "it doesn't fit on one line" do
+        let(:condition) { 'a' * 27 }
+
+        it "doesn't register an offense" do
+          # This if statement fits exactly on one line if written as a
+          # modifier.
+          expect("#{body} if #{condition}".length).to eq(69)
+
+          inspect_source(source)
+          expect(cop.offenses.empty?).to be(true)
+        end
+      end
+    end
+  end
 end