Handle arrow operator for attr_* and procs

lib/tapioca/gem/listeners/yard_doc.rb

@@ -69,7 +69,7 @@ def documentation_comments(name, sigs: [])
             .reject { |line| IGNORED_COMMENTS.any? { |comment| line.include?(comment) } }
             .map! do |line|
               if line.strip.start_with?(RBS_SIGNATURE_PREFIX)
-                rbs_sigs << RBI::RBSSig.new(line[1..].strip)
+                rbs_sigs << create_rbs_sig(line)
               else
                 comments << RBI::Comment.new(line)
               end
@@ -107,6 +107,25 @@ def documentation_comments(name, sigs: [])
           [comments, rbs_sigs]
         end
 
+        #: (String line) -> RBI::RBSSig
+        def create_rbs_sig(line)
+          sig = T.must(line[1..]).strip
+
+          # attr_* methods don't have to specify "->" in their signatures but since we convert it
+          # to a regular method definitions we need to have "->" to represent the return type.
+          # Also we need becareful of proc types since they contain a "->" already.
+          if !sig.include?("->")
+            sig = "-> #{sig}"
+          elsif sig.include?("^") # Proc type
+            # Check if there's a "->" that's not inside a proc type
+            # A proc type will have the form (^(Arg1, Arg2) -> ReturnType)
+            outer_arrow_present = !/\([^()]*->[^()]*\)/.match?(sig)
+            sig = "-> #{sig}" unless outer_arrow_present
+          end
+
+          RBI::RBSSig.new(sig)
+        end
+
         # @override
         #: (NodeAdded event) -> bool
         def ignore?(event)

spec/tapioca/gem/pipeline_spec.rb

@@ -4550,16 +4550,44 @@ def foo; end
 
           #: -> Integer
           def self.bar; end
+
+          #: Integer
+          attr_reader :baz
+
+          #: (^(Integer) -> String) -> void
+          attr_reader :qux
+
+          #: (^(Integer) -> String proc) -> void
+          def quux(proc); end
+
+          #: ((^(Integer) -> String proc) -> void) -> void
+          def corge(nested_proc); end
         end
       RUBY
 
       output = template(<<~RBI)
         # source://#{DEFAULT_GEM_NAME}//lib/foo.rb#1
         class Foo
+          # source://#{DEFAULT_GEM_NAME}//lib/foo.rb#9
+          #: -> Integer
+          def baz; end
+
+          # source://#{DEFAULT_GEM_NAME}//lib/foo.rb#18
+          #: ((^(Integer) -> String proc) -> void) -> void
+          def corge(nested_proc); end
+
           # source://#{DEFAULT_GEM_NAME}//lib/foo.rb#3
           #: -> String
           def foo; end
 
+          # source://#{DEFAULT_GEM_NAME}//lib/foo.rb#15
+          #: (^(Integer) -> String proc) -> void
+          def quux(proc); end
+
+          # source://#{DEFAULT_GEM_NAME}//lib/foo.rb#12
+          #: (^(Integer) -> String) -> void
+          def qux; end
+
           class << self
             # source://#{DEFAULT_GEM_NAME}//lib/foo.rb#6
             #: -> Integer