Fix counter increment for Ruby 2.x

Adding default values to arguments in 7df0d8e broke these methods in Ruby 2.x due to the differences in keyword arguments handling in Ruby 2.x that were fixed in Ruby 3.x

See https://www.ruby-lang.org/en/news/2019/12/12/separation-of-positional-and-keyword-arguments-in-ruby-3-0/ for more details

Fixes #40

CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ## Unreleased
 
+### Fixed
+
+- Compatibility with Ruby 2.x, broken in 0.13.0 due to differences of keywords handling in Ruby 2.x for case when method has arguments with default values. [@Envek]
+
 ## 0.13.0 - 2024-10-02
 
 ### Added

lib/yabeda.rb

@@ -13,6 +13,8 @@
 module Yabeda
   include DSL
 
+  EMPTY_TAGS = {}.freeze
+
   class << self
     extend Forwardable
 

lib/yabeda/counter.rb

@@ -3,7 +3,12 @@
 module Yabeda
   # Growing-only counter
   class Counter < Metric
-    def increment(tags = {}, by: 1)
+    # @overload increment(tags = {}, by: 1)
+    #   Increment the counter for given set of tags by the given increment value
+    #   @param tags Hash{Symbol=>#to_s} tags to identify the counter
+    #   @param by [Integer] strictly positive increment value
+    def increment(*args)
+      tags, by = self.class.parse_args(*args)
       all_tags = ::Yabeda::Tags.build(tags, group)
       values[all_tags] += by
       adapters.each_value do |adapter|
@@ -15,5 +20,25 @@ def increment(tags = {}, by: 1)
     def values
       @values ||= Concurrent::Hash.new(0)
     end
+
+    # @api private
+    # rubocop:disable Metrics/MethodLength
+    def self.parse_args(*args)
+      case args.size
+      when 0 # increment()
+        [EMPTY_TAGS, 1]
+      when 1 # increment(by: 5) or increment(tags)
+        if args[0].key?(:by)
+          [EMPTY_TAGS, args.fetch(:by)]
+        else
+          [args[0], 1]
+        end
+      when 2 # increment(tags, by: 5)
+        [args[0], args[1].fetch(:by, 1)]
+      else
+        raise ArgumentError, "wrong number of arguments (given #{args.size}, expected 0..2)"
+      end
+    end
+    # rubocop:enable Metrics/MethodLength
   end
 end

lib/yabeda/gauge.rb

@@ -12,11 +12,21 @@ def set(tags, value)
       value
     end
 
-    def increment(tags = {}, by: 1)
+    # @overload increment(tags = {}, by: 1)
+    #   Convenience method to increment current gauge value for given set of tags by the given increment value
+    #   @param tags Hash{Symbol=>#to_s} tags to identify the gauge
+    #   @param by [Integer] increment value
+    def increment(*args)
+      tags, by = Counter.parse_args(*args)
       set(tags, get(tags).to_i + by)
     end
 
-    def decrement(tags = {}, by: 1)
+    # @overload decrement(tags = {}, by: 1)
+    #   Convenience method to decrement current gauge value for given set of tags by the given decrement value
+    #   @param tags Hash{Symbol=>#to_s} tags to identify the gauge
+    #   @param by [Integer] decrement value
+    def decrement(*args)
+      tags, by = Counter.parse_args(*args)
       set(tags, get(tags).to_i - by)
     end
   end