Fix floating formatting

lib/m3u8/attribute_formatter.rb

@@ -1,5 +1,7 @@
 # frozen_string_literal: true
 
+require 'bigdecimal'
+
 module M3u8
   # Shared helpers for formatting HLS tag attributes
   module AttributeFormatter
@@ -26,5 +28,20 @@ def unquoted_format(key, value)
     def boolean_format(key, value)
       "#{key}=#{value == true ? 'YES' : 'NO'}" unless value.nil?
     end
+
+    # Format a decimal attribute, ensuring it formatted as a floating-point
+    # number or integer
+    # @param number [Float, Integer, nil] the number to format
+    # @return [String, nil] formatted string or nil when value is nil
+    def decimal_format(number)
+      case number
+      when nil
+        nil
+      when Float
+        BigDecimal(number).to_s('F')
+      else
+        number.to_s
+      end
+    end
   end
 end

lib/m3u8/date_range_item.rb

@@ -131,8 +131,8 @@ def formatted_attributes
        quoted_format('CLASS', class_name),
        %(START-DATE="#{start_date}"),
        quoted_format('END-DATE', end_date),
-       unquoted_format('DURATION', duration),
-       unquoted_format('PLANNED-DURATION', planned_duration),
+       unquoted_format('DURATION', decimal_format(duration)),
+       unquoted_format('PLANNED-DURATION', decimal_format(planned_duration)),
        client_attributes_format,
        interstitial_formats,
        unquoted_format('SCTE35-CMD', scte35_cmd),
@@ -147,7 +147,7 @@ def client_attributes_format
 
       client_attributes.map do |attribute|
         value = attribute.last
-        fmt = decimal?(value) ? value : %("#{value}")
+        fmt = decimal?(value) ? decimal_format(value) : %("#{value}")
         "#{attribute.first}=#{fmt}"
       end
     end
@@ -166,8 +166,8 @@ def decimal?(value)
     def interstitial_formats
       [quoted_format('X-ASSET-URI', asset_uri),
        quoted_format('X-ASSET-LIST', asset_list),
-       unquoted_format('X-RESUME-OFFSET', resume_offset),
-       unquoted_format('X-PLAYOUT-LIMIT', playout_limit),
+       unquoted_format('X-RESUME-OFFSET', decimal_format(resume_offset)),
+       unquoted_format('X-PLAYOUT-LIMIT', decimal_format(playout_limit)),
        quoted_format('X-RESTRICT', restrict),
        quoted_format('X-SNAP', snap),
        quoted_format('X-TIMELINE-OCCUPIES', timeline_occupies),

lib/m3u8/part_item.rb

@@ -45,7 +45,7 @@ def to_s
     private
 
     def formatted_attributes
-      [unquoted_format('DURATION', duration),
+      [unquoted_format('DURATION', decimal_format(duration)),
        quoted_format('URI', uri),
        independent_format,
        quoted_format('BYTERANGE', byterange),

lib/m3u8/segment_item.rb

@@ -5,6 +5,7 @@ module M3u8
   # optionally allowing an EXT-X-BYTERANGE tag to be set.
   class SegmentItem
     include M3u8
+    include AttributeFormatter
 
     # @return [Float, nil] segment duration in seconds
     # @return [String, nil] segment URI
@@ -32,7 +33,7 @@ def self.parse(text)
     # Render as an m3u8 EXTINF tag with segment URI.
     # @return [String]
     def to_s
-      "#EXTINF:#{duration},#{comment}#{byterange_format}" \
+      "#EXTINF:#{decimal_format(duration)},#{comment}#{byterange_format}" \
         "\n#{date_format}#{segment}"
     end
 

m3u8.gemspec

@@ -22,6 +22,7 @@ Gem::Specification.new do |spec|
   spec.files         = `git ls-files -z`.split("\x0")
                                         .grep_v(/\A(CLAUDE|AGENTS)\.md\z/)
   spec.executables   = spec.files.grep(%r{^bin/}) { |f| File.basename(f) }
+  spec.add_dependency 'bigdecimal'
   spec.require_paths = ['lib']
 
 end

spec/lib/m3u8/date_range_item_spec.rb

@@ -172,6 +172,26 @@
       expect(item.to_s).to eq(expected)
     end
 
+    it 'should render small float values as floating-point number instead of scientific notation' do
+      options = { id: 'test_id', start_date: '2014-03-05T11:15:00Z',
+                  duration: 0.00001,
+                  planned_duration: 0.00002,
+                  resume_offset: 0.00003,
+                  playout_limit: 0.00004,
+                  client_attributes: { 'X-CUSTOM' => 0.00005 } }
+      item = described_class.new(options)
+
+      expected = '#EXT-X-DATERANGE:ID="test_id",' \
+                 'START-DATE="2014-03-05T11:15:00Z",' \
+                 'DURATION=0.00001,' \
+                 'PLANNED-DURATION=0.00002,' \
+                 'X-CUSTOM=0.00005,' \
+                 'X-RESUME-OFFSET=0.00003,' \
+                 'X-PLAYOUT-LIMIT=0.00004'
+
+      expect(item.to_s).to eq(expected)
+    end
+
     it 'should ignore optional attributes' do
       options = { id: 'test_id', start_date: '2014-03-05T11:15:00Z' }
       item = described_class.new(options)

spec/lib/m3u8/part_item_spec.rb

@@ -56,5 +56,12 @@
       expected = '#EXT-X-PART:DURATION=1.5,URI="part1.ts"'
       expect(item.to_s).to eq(expected)
     end
+
+    it 'should render small float values as floating-point number instead of scientific notation' do
+      options = { duration: 0.00001, uri: 'part1.ts' }
+      item = described_class.new(options)
+      expected = '#EXT-X-PART:DURATION=0.00001,URI="part1.ts"'
+      expect(item.to_s).to eq(expected)
+    end
   end
 end

spec/lib/m3u8/segment_item_spec.rb

@@ -89,4 +89,15 @@
                'segment.aac'
     expect(output).to eq expected
   end
+
+  it 'converts very small durations to floating point' do
+    time = Time.iso8601('2020-11-25T20:27:00Z')
+    hash = { duration: 0.000001, segment: 'test.ts', program_date_time: time }
+    item = M3u8::SegmentItem.new(hash)
+    output = item.to_s
+    expected = "#EXTINF:0.000001,\n" \
+               "#EXT-X-PROGRAM-DATE-TIME:2020-11-25T20:27:00Z\n" \
+               'test.ts'
+    expect(output).to eq expected
+  end
 end