MemoizedValue memoizes nil results (#2053)

I moved the existing `subject` into the test because it didn't make sense for the second test I added.

1 files changed, 13 insertions, 3 deletions

diff --git a/spec/config/memoized_value_spec.rb b/spec/config/memoized_value_spec.rb
index 22e278dc..9b8ab864 100644
--- a/spec/config/memoized_value_spec.rb
+++ b/spec/config/memoized_value_spec.rb
@@ -2,10 +2,20 @@
 
 RSpec.describe Pry::Config::MemoizedValue do
   describe "#call" do
-    subject { described_class.new { rand } }
-
     it "memoizes the result of call" do
-      expect(subject.call).to eq(subject.call)
+      instance = described_class.new { rand }
+      expect(instance.call).to eq(instance.call)
+    end
+
+    it "doesn't conflate falsiness with unmemoizedness" do
+      count = 0
+      instance = described_class.new do
+        count += 1
+        nil
+      end
+      expect(instance.call).to eq nil
+      expect(instance.call).to eq nil
+      expect(count).to eq 1
     end
   end
 end