add logic to support semver comparisons (#16)

Gemfile

@@ -3,3 +3,5 @@
 source 'http://rubygems.org'
 
 gemspec
+
+gem 'semver2', '~> 3.4', '>= 3.4.2'

Gemfile.lock

@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    eppo-server-sdk (0.2.3)
+    eppo-server-sdk (0.2.4)
       concurrent-ruby (~> 1.1, >= 1.1.9)
       faraday (~> 2.7, >= 2.7.1)
       faraday-retry (~> 2.0, >= 2.0.0)
@@ -12,18 +12,20 @@ GEM
     addressable (2.8.1)
       public_suffix (>= 2.0.2, < 6.0)
     ast (2.4.2)
-    concurrent-ruby (1.1.10)
+    concurrent-ruby (1.2.3)
     crack (0.4.5)
       rexml
     diff-lcs (1.5.0)
-    faraday (2.7.2)
-      faraday-net_http (>= 2.0, < 3.1)
-      ruby2_keywords (>= 0.0.4)
-    faraday-net_http (3.0.2)
-    faraday-retry (2.0.0)
+    faraday (2.9.0)
+      faraday-net_http (>= 2.0, < 3.2)
+    faraday-net_http (3.1.0)
+      net-http
+    faraday-retry (2.2.0)
       faraday (~> 2.0)
     hashdiff (1.0.1)
     jaro_winkler (1.5.6)
+    net-http (0.4.1)
+      uri
     parallel (1.22.1)
     parser (3.2.0.0)
       ast (~> 2.4.1)
@@ -53,8 +55,9 @@ GEM
       ruby-progressbar (~> 1.7)
       unicode-display_width (>= 1.4.0, < 2.0)
     ruby-progressbar (1.11.0)
-    ruby2_keywords (0.0.5)
+    semver2 (3.4.2)
     unicode-display_width (1.8.0)
+    uri (0.13.0)
     webmock (3.18.1)
       addressable (>= 2.8.0)
       crack (>= 0.3.2)
@@ -69,6 +72,7 @@ DEPENDENCIES
   rake (~> 13.0, >= 13.0.6)
   rspec (~> 3.12, >= 3.12.0)
   rubocop (~> 0.82.0)
+  semver2 (~> 3.4, >= 3.4.2)
   webmock (~> 3.18, >= 3.18.1)
 
 BUNDLED WITH

lib/eppo_client/rules.rb

@@ -1,5 +1,7 @@
 # frozen_string_literal: true
 
+require 'semver'
+
 # The helper module for rules
 module EppoClient
   module OperatorType
@@ -60,7 +62,12 @@ def evaluate_condition(subject_attributes, condition)
     when OperatorType::NOT_ONE_OF
       !condition.value.map(&:downcase).include?(subject_value.to_s.downcase)
     else
-      subject_value.is_a?(Numeric) && evaluate_numeric_condition(subject_value, condition)
+      # Numeric operator: value could be numeric or semver.
+      if subject_value.is_a?(Numeric)
+        evaluate_numeric_condition(subject_value, condition)
+      elsif valid_semver?(subject_value)
+        compare_semver(subject_value, condition.value, condition.operator)
+      end
     end
   end
   # rubocop:enable Metrics/AbcSize, Metrics/MethodLength
@@ -82,6 +89,31 @@ def evaluate_numeric_condition(subject_value, condition)
   end
   # rubocop:enable Metrics/MethodLength
 
+  # rubocop:disable Metrics/MethodLength
+  def compare_semver(attribute_value, condition_value, operator)
+    unless valid_semver?(attribute_value) && valid_semver?(condition_value)
+      return false
+    end
+
+    case operator
+    when OperatorType::GT
+      SemVer.parse(attribute_value) > SemVer.parse(condition_value)
+    when OperatorType::GTE
+      SemVer.parse(attribute_value) >= SemVer.parse(condition_value)
+    when OperatorType::LT
+      SemVer.parse(attribute_value) < SemVer.parse(condition_value)
+    when OperatorType::LTE
+      SemVer.parse(attribute_value) <= SemVer.parse(condition_value)
+    else
+      false
+    end
+  end
+  # rubocop:enable Metrics/MethodLength
+
+  def valid_semver?(string)
+    !SemVer.parse(string).nil?
+  end
+
   module_function :find_matching_rule, :matches_rule, :evaluate_condition,
-                  :evaluate_numeric_condition
+                  :evaluate_numeric_condition, :valid_semver?, :compare_semver
 end

lib/eppo_client/version.rb

@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module EppoClient
-  VERSION = '0.2.3'
+  VERSION = '0.2.4'
 end

spec/rules_spec.rb

@@ -16,6 +16,7 @@
 rule_with_empty_conditions = EppoClient::Rule.new(allocation_key: 'allocation', conditions: [])
 
 # rubocop:disable Metrics/BlockLength
+# rubocop:disable Layout/LineLength
 describe EppoClient::Rule do
   it 'tests find_matching_rule_when_no_rules_match' do
     subject_attributes = { 'age' => 20, 'country' => 'US' }
@@ -44,6 +45,40 @@
     expect(EppoClient.find_matching_rule({ 'age' => '99' }, [numeric_rule])).to be_nil
   end
 
+  it 'tests find matching rule for semver string' do
+    semver_greater_than_condition = EppoClient::Condition.new(
+      operator: EppoClient::OperatorType::GTE, value: '1.0.0', attribute: 'version'
+    )
+    semver_less_than_condition = EppoClient::Condition.new(
+      operator: EppoClient::OperatorType::LTE, value: '2.0.0', attribute: 'version'
+    )
+    semver_rule = EppoClient::Rule.new(
+      allocation_key: 'allocation',
+      conditions: [semver_less_than_condition, semver_greater_than_condition]
+    )
+
+    expect(EppoClient.find_matching_rule({ 'version' => '1.1.0' }, [semver_rule])).to be(semver_rule)
+    expect(EppoClient.find_matching_rule({ 'version' => '2.0.0' }, [semver_rule])).to be(semver_rule)
+    expect(EppoClient.find_matching_rule({ 'version' => '2.1.0' }, [semver_rule])).to be_nil
+  end
+
+  it 'tests find matching rule for semver string, ensuring it is not interpreted lexographically' do
+    semver_greater_than_condition = EppoClient::Condition.new(
+      operator: EppoClient::OperatorType::GTE, value: '1.2.3', attribute: 'version'
+    )
+
+    semver_less_than_condition = EppoClient::Condition.new(
+      operator: EppoClient::OperatorType::LTE, value: '1.15.0', attribute: 'version'
+    )
+
+    semver_rule = EppoClient::Rule.new(
+      allocation_key: 'allocation',
+      conditions: [semver_less_than_condition, semver_greater_than_condition]
+    )
+
+    expect(EppoClient.find_matching_rule({ 'version' => '1.12.0' }, [semver_rule])).to be(semver_rule)
+  end
+
   it 'tests find matching rule with numeric value and regex' do
     condition = EppoClient::Condition.new(
       operator: EppoClient::OperatorType::MATCHES, value: '[0-9]+', attribute: 'age'
@@ -138,3 +173,4 @@
   end
 end
 # rubocop:enable Metrics/BlockLength
+# rubocop:enable Layout/LineLength