Add support for NaN in RESP3 protocol

Fix: #143

This was initially missing from the spec and added about a
year ago: redis/redis-specifications#10

CHANGELOG.md

@@ -1,5 +1,8 @@
 # Unreleased
 
+- Add support for `NaN` in RESP3 protocol doubles.
+  This was initially missing from the spec and added about a year ago.
+
 # 0.17.0
 
 - Adds `sentinel_username` and `sentinel_password` options for `RedisClient#sentinel`

hiredis-client/ext/redis_client/hiredis/vendor/read.c

@@ -303,6 +303,9 @@ static int processLineItem(redisReader *r) {
                     d = INFINITY; /* Positive infinite. */
                 } else if (strcasecmp(buf,",-inf") == 0) {
                     d = -INFINITY; /* Negative infinite. */
+                } else if ((len == 3 && strcasecmp(buf,"nan") == 0) ||
+                            (len == 4 && strcasecmp(buf, "-nan") == 0)) {
+                     d = NAN; /* nan. */
                 } else {
                     d = strtod((char*)buf,&eptr);
                     if (buf[0] == '\0' || eptr[0] != '\0' || isnan(d)) {

lib/redis_client/ruby_connection/resp3.rb

@@ -175,6 +175,8 @@ def parse_integer(io)
 
     def parse_double(io)
       case value = io.gets_chomp
+      when "nan"
+        Float::NAN
       when "inf"
         Float::INFINITY
       when "-inf"

test/redis_client/resp3_test.rb

@@ -90,6 +90,9 @@ def test_load_double
       assert_parses(-42.42, ",-42.42\r\n")
       assert_parses Float::INFINITY, ",inf\r\n"
       assert_parses(-Float::INFINITY, ",-inf\r\n")
+      assert_parses(nil, ",nan\r\n") do |actual|
+        assert_predicate actual, :nan?
+      end
     end
 
     def test_load_null
@@ -132,10 +135,13 @@ def test_load_verbatim_string
     def assert_parses(expected, payload)
       raw_io = StringIO.new(payload.b)
       io = RedisClient::RubyConnection::BufferedIO.new(raw_io, read_timeout: 1, write_timeout: 1)
-      if expected.nil?
-        assert_nil RESP3.load(io)
+      actual = RESP3.load(io)
+      if block_given?
+        yield actual
+      elsif expected.nil?
+        assert_nil actual
       else
-        assert_equal(expected, RESP3.load(io))
+        assert_equal(expected, actual)
       end
 
       assert io.eof?, "Expected IO to be fully consumed: #{raw_io.read.inspect}"