[Fix #13751] Fix false positive in Layout/ExtraSpacing with ForceEqualSignAlignment: true for endless methods

dvandersluis · bbatsov · commit 3dc1694b3a4e · 2025-01-31T10:46:32.000+01:00
diff --git a/changelog/fix_fix_false_positive_in_layout_extra_spacing_with_20250130132538.md b/changelog/fix_fix_false_positive_in_layout_extra_spacing_with_20250130132538.md
@@ -0,0 +1 @@
+* [#13751](https://github.com/rubocop/rubocop/issues/13751): Fix false positive in `Layout/ExtraSpacing` with `ForceEqualSignAlignment: true` for endless methods. ([@dvandersluis][])
diff --git a/lib/rubocop/cop/mixin/preceding_following_alignment.rb b/lib/rubocop/cop/mixin/preceding_following_alignment.rb
@@ -4,6 +4,7 @@ module RuboCop
   module Cop
     # Common functionality for checking whether an AST node/token is aligned
     # with something on a preceding or following line
+    # rubocop:disable Metrics/ModuleLength
     module PrecedingFollowingAlignment
       # Tokens that end with an `=`, as well as `<<`, that can be aligned together:
       # `=`, `==`, `===`, `!=`, `<=`, `>=`, `<<` and operator assignment (`+=`, etc).
@@ -156,10 +157,14 @@ def assignment_tokens
         @assignment_tokens ||= begin
           tokens = processed_source.tokens.select(&:equal_sign?)
 
-          # we don't want to operate on equals signs which are part of an
-          #   optarg in a method definition
-          # e.g.: def method(optarg = default_val); end
-          tokens = remove_optarg_equals(tokens, processed_source)
+          # We don't want to operate on equals signs which are part of an `optarg` in a
+          # method definition, or the separator of an endless method definition.
+          # For example (the equals sign to ignore is highlighted with ^):
+          #     def method(optarg = default_val); end
+          #                       ^
+          #     def method = foo
+          #                ^
+          tokens = remove_equals_in_def(tokens, processed_source)
 
           # Only attempt to align the first = on each line
           Set.new(tokens.uniq(&:line))
@@ -195,11 +200,20 @@ def relevant_assignment_lines(line_range)
       # rubocop:enable Metrics/AbcSize, Metrics/CyclomaticComplexity
       # rubocop:enable Metrics/PerceivedComplexity, Metrics/MethodLength
 
-      def remove_optarg_equals(asgn_tokens, processed_source)
-        optargs    = processed_source.ast.each_node(:optarg)
-        optarg_eql = optargs.to_set { |o| o.loc.operator.begin_pos }
-        asgn_tokens.reject { |t| optarg_eql.include?(t.begin_pos) }
+      def remove_equals_in_def(asgn_tokens, processed_source)
+        nodes = processed_source.ast.each_node(:optarg, :def)
+        eqls_to_ignore = nodes.with_object([]) do |node, arr|
+          loc = if node.def_type?
+                  node.loc.assignment if node.endless?
+                else
+                  node.loc.operator
+                end
+          arr << loc.begin_pos if loc
+        end
+
+        asgn_tokens.reject { |t| eqls_to_ignore.include?(t.begin_pos) }
       end
     end
+    # rubocop:enable Metrics/ModuleLength
   end
 end
diff --git a/spec/rubocop/cop/layout/extra_spacing_spec.rb b/spec/rubocop/cop/layout/extra_spacing_spec.rb
@@ -628,6 +628,24 @@ def method(arg = 1)
         opt.ssh_config[e] = f
       RUBY
     end
+
+    context 'endless methods', :ruby30 do
+      it 'does not register an offense when not aligned' do
+        expect_no_offenses(<<~RUBY)
+          def deleted = do_something
+          def updated = do_something
+          def added = do_something
+        RUBY
+      end
+
+      it 'does not register an offense with optional values' do
+        expect_no_offenses(<<~RUBY)
+          def deleted(x = true) = do_something(x)
+          def updated(x = true) = do_something(x)
+          def added(x = true) = do_something(x)
+        RUBY
+      end
+    end
   end
 
   context 'when exactly two comments have extra spaces' do

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1 @@`
	`1`	+* [#13751](https://github.com/rubocop/rubocop/issues/13751): Fix false positive in `Layout/ExtraSpacing` with `ForceEqualSignAlignment: true` for endless methods. ([@dvandersluis][])