Merge pull request #28 from launchdarkly/eb/sc-136142/jruby-zero-delay

fix error when delay is zero in JRuby

Author: eli-darkly

lib/ld-eventsource/impl/backoff.rb

@@ -41,7 +41,11 @@ def next_interval
         @last_good_time = nil
         target = ([@base_interval * (2 ** @attempts), @max_interval].min).to_f
         @attempts += 1
-        (target / 2) + @jitter_rand.rand(target / 2)
+        if target == 0
+          0  # in some Ruby versions it's illegal to call rand(0)
+        else
+          (target / 2) + @jitter_rand.rand(target / 2)
+        end
       end
 
       #

spec/backoff_spec.rb

@@ -47,6 +47,17 @@ module Impl
         expect(interval).to be <= (initial * 2)
         expect(interval).to be >= initial
       end
+
+      it "always returns zero if the initial delay is zero" do
+        initial = 0
+        max = 60
+        b = Backoff.new(initial, max)
+        
+        for i in 1..6 do
+          interval = b.next_interval
+          expect(interval).to eq(0)
+        end
+      end
     end
   end
 end