feat: support starts_with and ends_with operators in local evaluation

.changeset/starts-with-ends-with-operators.md

@@ -0,0 +1,5 @@
+---
+"posthog-ruby": minor
+---
+
+Support the `starts_with`, `not_starts_with`, `ends_with`, and `not_ends_with` property filter operators in feature flag local evaluation. Matching is case-insensitive and mirrors `icontains`, so flags using these operators no longer fall back to remote evaluation.

lib/posthog/feature_flags.rb

@@ -654,6 +654,14 @@ def self.match_property(property, property_values, cohort_properties = {})
         override_value.to_s.downcase.include?(value.to_s.downcase)
       when 'not_icontains'
         !override_value.to_s.downcase.include?(value.to_s.downcase)
+      when 'starts_with'
+        override_value.to_s.downcase.start_with?(value.to_s.downcase)
+      when 'not_starts_with'
+        !override_value.to_s.downcase.start_with?(value.to_s.downcase)
+      when 'ends_with'
+        override_value.to_s.downcase.end_with?(value.to_s.downcase)
+      when 'not_ends_with'
+        !override_value.to_s.downcase.end_with?(value.to_s.downcase)
       when 'regex'
         PostHog::Utils.is_valid_regex(value.to_s) && !Regexp.new(value.to_s).match(override_value.to_s).nil?
       when 'not_regex'

spec/posthog/feature_flag_spec.rb

@@ -1475,6 +1475,77 @@ module PostHog
       expect(FeatureFlagsPoller.match_property(property_b, { 'key' => 'three' })).to be false
     end
 
+    it 'with operator starts_with' do
+      property_a = { 'key' => 'key', 'value' => 'Val', 'operator' => 'starts_with' }
+
+      expect(FeatureFlagsPoller.match_property(property_a, { 'key' => 'value' })).to be true
+      expect(FeatureFlagsPoller.match_property(property_a, { 'key' => 'VALUE' })).to be true
+      expect(FeatureFlagsPoller.match_property(property_a, { 'key' => 'vaLue4' })).to be true
+
+      expect(FeatureFlagsPoller.match_property(property_a, { 'key' => 'prevalue' })).to be false
+      expect(FeatureFlagsPoller.match_property(property_a, { 'key' => 'Alakazam' })).to be false
+      expect(FeatureFlagsPoller.match_property(property_a, { 'key' => '' })).to be false
+      expect(FeatureFlagsPoller.match_property(property_a, { 'key' => nil })).to be false
+      expect(FeatureFlagsPoller.match_property(property_a, { 'key' => 123 })).to be false
+
+      expect do
+        FeatureFlagsPoller.match_property(property_a, { 'key2' => 'value' })
+      end.to raise_error(InconclusiveMatchError)
+      expect { FeatureFlagsPoller.match_property(property_a, {}) }.to raise_error(InconclusiveMatchError)
+
+      property_b = { 'key' => 'key', 'value' => '3', 'operator' => 'starts_with' }
+
+      expect(FeatureFlagsPoller.match_property(property_b, { 'key' => '3' })).to be true
+      expect(FeatureFlagsPoller.match_property(property_b, { 'key' => 323 })).to be true
+
+      expect(FeatureFlagsPoller.match_property(property_b, { 'key' => 123 })).to be false
+      expect(FeatureFlagsPoller.match_property(property_b, { 'key' => 'val3' })).to be false
+
+      property_c = { 'key' => 'key', 'value' => 'Val', 'operator' => 'not_starts_with' }
+
+      expect(FeatureFlagsPoller.match_property(property_c, { 'key' => 'value' })).to be false
+      expect(FeatureFlagsPoller.match_property(property_c, { 'key' => 'VALUE' })).to be false
+
+      expect(FeatureFlagsPoller.match_property(property_c, { 'key' => 'prevalue' })).to be true
+      expect(FeatureFlagsPoller.match_property(property_c, { 'key' => 'Alakazam' })).to be true
+    end
+
+    it 'with operator ends_with' do
+      property_a = { 'key' => 'key', 'value' => 'lUe', 'operator' => 'ends_with' }
+
+      expect(FeatureFlagsPoller.match_property(property_a, { 'key' => 'value' })).to be true
+      expect(FeatureFlagsPoller.match_property(property_a, { 'key' => 'VALUE' })).to be true
+      expect(FeatureFlagsPoller.match_property(property_a, { 'key' => '343tfvalue' })).to be true
+
+      expect(FeatureFlagsPoller.match_property(property_a, { 'key' => 'value2' })).to be false
+      expect(FeatureFlagsPoller.match_property(property_a, { 'key' => 'Alakazam' })).to be false
+      expect(FeatureFlagsPoller.match_property(property_a, { 'key' => '' })).to be false
+      expect(FeatureFlagsPoller.match_property(property_a, { 'key' => nil })).to be false
+      expect(FeatureFlagsPoller.match_property(property_a, { 'key' => 123 })).to be false
+
+      expect do
+        FeatureFlagsPoller.match_property(property_a, { 'key2' => 'value' })
+      end.to raise_error(InconclusiveMatchError)
+      expect { FeatureFlagsPoller.match_property(property_a, {}) }.to raise_error(InconclusiveMatchError)
+
+      property_b = { 'key' => 'key', 'value' => '3', 'operator' => 'ends_with' }
+
+      expect(FeatureFlagsPoller.match_property(property_b, { 'key' => '3' })).to be true
+      expect(FeatureFlagsPoller.match_property(property_b, { 'key' => 323 })).to be true
+      expect(FeatureFlagsPoller.match_property(property_b, { 'key' => 13 })).to be true
+
+      expect(FeatureFlagsPoller.match_property(property_b, { 'key' => 321 })).to be false
+      expect(FeatureFlagsPoller.match_property(property_b, { 'key' => '3val' })).to be false
+
+      property_c = { 'key' => 'key', 'value' => 'lUe', 'operator' => 'not_ends_with' }
+
+      expect(FeatureFlagsPoller.match_property(property_c, { 'key' => 'value' })).to be false
+      expect(FeatureFlagsPoller.match_property(property_c, { 'key' => 'VALUE' })).to be false
+
+      expect(FeatureFlagsPoller.match_property(property_c, { 'key' => 'value2' })).to be true
+      expect(FeatureFlagsPoller.match_property(property_c, { 'key' => 'Alakazam' })).to be true
+    end
+
     it 'with operator regex' do
       property_a = { 'key' => 'key', 'value' => '\.com$', 'operator' => 'regex' }