Fix computing Timestamps in Ruby

messages/CHANGELOG.md

@@ -17,6 +17,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Fixed
 
+* [Ruby] Fix computing of Timestamp (see [cucumber-ruby#1438](https://github.com/cucumber/cucumber-ruby/issues/1438))
+
 ## [12.2.0] - 2020-06-26
 
 ### Added

messages/ruby/lib/cucumber/messages/time_conversion.rb

@@ -4,12 +4,14 @@ module TimeConversion
       NANOSECONDS_PER_SECOND = 1000000000
 
       def time_to_timestamp(time)
-        rational = time.to_r
-        Timestamp.new(seconds: rational.numerator, nanos: rational.denominator)
+        Timestamp.new(
+          seconds: time.to_i,
+          nanos: time.nsec
+        )
       end
 
       def timestamp_to_time(timestamp)
-        Time.at(Rational(timestamp.seconds, timestamp.nanos))
+        Time.at(timestamp.seconds + timestamp.nanos.to_f / NANOSECONDS_PER_SECOND)
       end
 
       def seconds_to_duration(seconds_float)

messages/ruby/spec/cucumber/messages/time_conversion_spec.rb

@@ -10,7 +10,7 @@ module Messages
         timestamp = time_to_timestamp(time)
         time_again = timestamp_to_time(timestamp)
 
-        expect(time_again).to eq(time)
+        expect(time).to be_within(0.000001).of(time_again)
       end
 
       it 'converts to and from seconds duration' do