first pass of changes for resolving issue

Gemfile

@@ -11,3 +11,4 @@ gem 'rubocop', '1.44.1'
 
 gem 'simplecov', '~> 0.22.0'
 gem 'simplecov-lcov', '~> 0.8.0'
+gem 'redis', '>= 5.0.0'

lib/mock_redis/set_methods.rb

@@ -7,22 +7,16 @@ module SetMethods
     include UtilityMethods
 
     def sadd(key, members)
-      members_class = members.class
       members = Array(members).map(&:to_s)
       assert_has_args(members, 'sadd')
 
       with_set_at(key) do |s|
-        size_before = s.size
         if members.size > 1
-          members.reverse_each { |m| s << m }
-          s.size - size_before
+          size_after(s) { members.reverse_each { |m| s << m } }
+        elsif redis_gem_v5?
+          size_after(s) { s.add?(members.first) }
         else
-          added = !!s.add?(members.first)
-          if members_class == Array
-            s.size - size_before
-          else
-            added
-          end
+          !!s.add?(members.first)
         end
       end
     end
@@ -125,14 +119,13 @@ def srandmember(key, count = nil)
     end
 
     def srem(key, members)
+      members = Array(members).map(&:to_s)
+
       with_set_at(key) do |s|
-        if members.is_a?(Array)
-          orig_size = s.size
-          members = members.map(&:to_s)
-          s.delete_if { |m| members.include?(m) }
-          orig_size - s.size
+        if members.size > 1 || redis_gem_v5?
+          size_after(s) { s.delete_if { |m| members.include?(m) } }
         else
-          !!s.delete?(members.to_s)
+          !!s.delete?(members.first)
         end
       end
     end
@@ -190,9 +183,12 @@ def sety?(key)
     def assert_sety(key)
       unless sety?(key)
         # Not the most helpful error, but it's what redis-rb barfs up
-        raise Redis::CommandError,
-              'WRONGTYPE Operation against a key holding the wrong kind of value'
+        raise wrong_type_error, 'WRONGTYPE Operation against a key holding the wrong kind of value'
       end
     end
+
+    def wrong_type_error
+      redis_gem_v5? ? Redis::WrongTypeError : Redis::CommandError
+    end
   end
 end

lib/mock_redis/utility_methods.rb

@@ -74,5 +74,15 @@ def left_pad(str, size)
 
       str
     end
+
+    def redis_gem_v5?
+      Redis::VERSION.to_i == 5
+    end
+
+    def size_after(obj, &blk)
+      size_before = obj.size
+      yield
+      (obj.size - size_before).abs
+    end
   end
 end

spec/commands/srem_spec.rb

@@ -8,24 +8,31 @@
     @redises.sadd(@key, 'ernie')
   end
 
-  it 'returns true if member is in the set' do
-    expect(@redises.srem(@key, 'bert')).to eq(true)
-  end
+  context "adapts to redis-rd version 4 and 5 outputs" do
+    include MockRedis::UtilityMethods
+
+    let(:positive_response) { redis_gem_v5? ? 1 : true }
+    let(:negative_response) { redis_gem_v5? ? 0 : false }
+
+    it 'returns positive response if member is in the set' do
+      expect(@redises.srem(@key, 'bert')).to eq(positive_response)
+    end
 
-  it 'returns false if member is not in the set' do
-    expect(@redises.srem(@key, 'cookiemonster')).to eq(false)
+    it 'returns negative response if member is not in the set' do
+      expect(@redises.srem(@key, 'cookiemonster')).to eq(negative_response)
+    end
+
+    it 'stringifies member' do
+      @redises.sadd(@key, '1')
+      expect(@redises.srem(@key, 1)).to eq(positive_response)
+    end
   end
 
   it 'removes member from the set' do
     @redises.srem(@key, 'ernie')
     expect(@redises.smembers(@key)).to eq(['bert'])
   end
 
-  it 'stringifies member' do
-    @redises.sadd(@key, '1')
-    expect(@redises.srem(@key, 1)).to eq(true)
-  end
-
   it 'cleans up empty sets' do
     @redises.smembers(@key).each { |m| @redises.srem(@key, m) }
     expect(@redises.get(@key)).to be_nil

spec/support/redis_multiplexer.rb

@@ -10,7 +10,7 @@ class RedisMultiplexer < BlankSlate
   def initialize(*a)
     super()
     @mock_redis = MockRedis.new(*a)
-    Redis.exists_returns_integer = true
+    configure_redis
     @real_redis = Redis.new(*a)
     _gsub_clear
   end
@@ -55,25 +55,25 @@ def _gsub_clear
     elsif !equalish?(mock_retval, real_retval) && !mock_error && !real_error
       # no exceptions, just different behavior
       raise MismatchedResponse,
-        "Mock failure: responses not equal.\n" \
-        "Redis.#{method}(#{args.inspect}) returned #{real_retval.inspect}\n" \
-        "MockRedis.#{method}(#{args.inspect}) returned #{mock_retval.inspect}\n"
+            "Mock failure: responses not equal.\n" \
+              "Redis.#{method}(#{args.inspect}) returned #{real_retval.inspect}\n" \
+              "MockRedis.#{method}(#{args.inspect}) returned #{mock_retval.inspect}\n"
     elsif !mock_error && real_error
       raise MismatchedResponse,
-        "Mock failure: didn't raise an error when it should have.\n" \
-        "Redis.#{method}(#{args.inspect}) raised #{real_error.inspect}\n" \
-        "MockRedis.#{method}(#{args.inspect}) raised nothing " \
-        "and returned #{mock_retval.inspect}"
+            "Mock failure: didn't raise an error when it should have.\n" \
+              "Redis.#{method}(#{args.inspect}) raised #{real_error.inspect}\n" \
+              "MockRedis.#{method}(#{args.inspect}) raised nothing " \
+              "and returned #{mock_retval.inspect}"
     elsif !real_error && mock_error
       raise MismatchedResponse,
-        "Mock failure: raised an error when it shouldn't have.\n" \
-        "Redis.#{method}(#{args.inspect}) returned #{real_retval.inspect}\n" \
-        "MockRedis.#{method}(#{args.inspect}) raised #{mock_error.inspect}"
+            "Mock failure: raised an error when it shouldn't have.\n" \
+              "Redis.#{method}(#{args.inspect}) returned #{real_retval.inspect}\n" \
+              "MockRedis.#{method}(#{args.inspect}) raised #{mock_error.inspect}"
     elsif mock_error && real_error && !equalish?(mock_error, real_error)
       raise MismatchedResponse,
-        "Mock failure: raised the wrong error.\n" \
-        "Redis.#{method}(#{args.inspect}) raised #{real_error.inspect}\n" \
-        "MockRedis.#{method}(#{args.inspect}) raised #{mock_error.inspect}"
+            "Mock failure: raised the wrong error.\n" \
+              "Redis.#{method}(#{args.inspect}) raised #{real_error.inspect}\n" \
+              "MockRedis.#{method}(#{args.inspect}) raised #{mock_error.inspect}"
     end
 
     raise mock_error if mock_error
@@ -121,4 +121,15 @@ def catch_errors
   rescue StandardError => e
     [nil, e]
   end
+
+  private
+
+  def configure_redis
+    case Redis::VERSION.to_i
+    when 5
+      # do nothing
+    else
+      Redis.exists_returns_integer = true
+    end
+  end
 end

spec/support/shared_examples/does_not_cleanup_empty_strings.rb

@@ -3,12 +3,12 @@
     key = 'mock-redis-test:not-a-string'
 
     method = method_from_description(example)
-    args = args_for_method(method).unshift(key)
+    args = [key, args_for_method(method)]
 
     @redises.set(key, '')
     expect do
       @redises.send(method, *args)
-    end.to raise_error(defined?(default_error) ? default_error : RuntimeError)
+    end.to raise_error(defined?(default_error) ? default_error : Redis::BaseError)
     expect(@redises.get(key)).to eq('')
   end
 end

spec/support/shared_examples/only_operates_on_sets.rb

@@ -3,12 +3,12 @@
     key = 'mock-redis-test:set-only'
 
     method = method_from_description(example)
-    args = args_for_method(method).unshift(key)
+    args = [key, args_for_method(method)]
 
     @redises.set(key, 1)
     expect do
       @redises.send(method, *args)
-    end.to raise_error(RuntimeError)
+    end.to raise_error(Redis::BaseError)
   end
 
   it_should_behave_like 'does not remove empty strings on error'