Merge branch 'da-fix-json-cache-false-values' into 'master'

Parse the cached value when it is false on Gitlab::JsonCache#read

See merge request gitlab-org/gitlab-ce!30061

lib/gitlab/json_cache.rb

@@ -34,7 +34,7 @@ module Gitlab
 
     def read(key, klass = nil)
       value = backend.read(cache_key(key))
-      value = parse_value(value, klass) if value
+      value = parse_value(value, klass) unless value.nil?
       value
     end
 

spec/lib/gitlab/json_cache_spec.rb

@@ -129,19 +129,52 @@ describe Gitlab::JsonCache do
         .with(expanded_key)
         .and_return(nil)
 
+      expect(ActiveSupport::JSON).not_to receive(:decode)
       expect(cache.read(key)).to be_nil
     end
 
-    context 'when the cached value is a boolean' do
+    context 'when the cached value is true' do
       it 'parses the cached value' do
         allow(backend).to receive(:read)
           .with(expanded_key)
           .and_return(true)
 
+        expect(ActiveSupport::JSON).to receive(:decode).with("true").and_call_original
         expect(cache.read(key, BroadcastMessage)).to eq(true)
       end
     end
 
+    context 'when the cached value is false' do
+      it 'parses the cached value' do
+        allow(backend).to receive(:read)
+          .with(expanded_key)
+          .and_return(false)
+
+        expect(ActiveSupport::JSON).to receive(:decode).with("false").and_call_original
+        expect(cache.read(key, BroadcastMessage)).to eq(false)
+      end
+    end
+
+    context 'when the cached value is a JSON true value' do
+      it 'parses the cached value' do
+        allow(backend).to receive(:read)
+          .with(expanded_key)
+          .and_return("true")
+
+        expect(cache.read(key, BroadcastMessage)).to eq(true)
+      end
+    end
+
+    context 'when the cached value is a JSON false value' do
+      it 'parses the cached value' do
+        allow(backend).to receive(:read)
+          .with(expanded_key)
+          .and_return("false")
+
+        expect(cache.read(key, BroadcastMessage)).to eq(false)
+      end
+    end
+
     context 'when the cached value is a hash' do
       it 'parses the cached value' do
         allow(backend).to receive(:read)