From 0c673650626e89fafd4799aec618667dc24153e2 Mon Sep 17 00:00:00 2001
From: Joseph Hughes <josephhughes129@gmail.com>
Date: Mon, 5 Feb 2024 15:36:05 +0000
Subject: [PATCH] Update Statsd tag serializer to allow falsy values

This instead now ensures that we skip including the tag value only if:
- it is equal to 'nil'
- it when stringified is equal to 'nil'

The reasoning for this was to make it so falsy values (e.g. false) will now be
included in our tag content, instead of skipped.
---
 lib/datadog/statsd/serialization/tag_serializer.rb |  8 ++++----
 spec/statsd/serialization/tag_serializer_spec.rb   | 14 ++++++++++++++
 2 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/lib/datadog/statsd/serialization/tag_serializer.rb b/lib/datadog/statsd/serialization/tag_serializer.rb
index 95860df..b6dc9b1 100644
--- a/lib/datadog/statsd/serialization/tag_serializer.rb
+++ b/lib/datadog/statsd/serialization/tag_serializer.rb
@@ -59,10 +59,10 @@ def to_tags_list(tags)
           case tags
           when Hash
             tags.map do |name, value|
-              if value
-                escape_tag_content("#{name}:#{value}")
-              else
+              if value&.to_s.nil?
                 escape_tag_content(name)
+              else
+                escape_tag_content("#{name}:#{value}")
               end
             end
           when Array
@@ -75,7 +75,7 @@ def to_tags_list(tags)
         def escape_tag_content(tag)
           tag = tag.to_s
           return tag unless tag.include?('|')
-          tag.delete('|,')        
+          tag.delete('|,')
         end
 
         def dd_tags(env = ENV)
diff --git a/spec/statsd/serialization/tag_serializer_spec.rb b/spec/statsd/serialization/tag_serializer_spec.rb
index d45be5f..a07b27b 100644
--- a/spec/statsd/serialization/tag_serializer_spec.rb
+++ b/spec/statsd/serialization/tag_serializer_spec.rb
@@ -139,6 +139,20 @@
         expect(subject.format([tag])).to eq 'node:storage'
       end
 
+      it 'ignores nil values and formats all other falsy values correctly' do
+        message_tags_hash = {
+          empty_array: [],
+          missing: nil,
+          'empty_hash' => {},
+          blank: '',
+          :false_value => false,
+          'results in blank': double('some tag', to_s: ''),
+          'results in nil': double('some tag', to_s: nil),
+        }
+
+        expect(subject.format(message_tags_hash)).to eq 'empty_array:[],missing,empty_hash:{},blank:,false_value:false,results in blank:,results in nil'
+      end
+
       it 'formats frozen tags correctly' do
         expect(subject.format(['name:foobarfoo'.freeze])).to eq 'name:foobarfoo'
       end