Update stream ID regex to support '('

lib/mock_redis/stream.rb

@@ -49,9 +49,15 @@ def range(start, finish, reversed, *opts_in)
       opts = options opts_in, ['count']
       start_id = MockRedis::Stream::Id.new(start)
       finish_id = MockRedis::Stream::Id.new(finish, sequence: Float::INFINITY)
-      items = members
-              .select { |m| (start_id <= m[0]) && (finish_id >= m[0]) }
-              .map { |m| [m[0].to_s, m[1]] }
+      if start_id.exclusive
+        items = members
+                .select { |m| (start_id < m[0]) && (finish_id >= m[0]) }
+                .map { |m| [m[0].to_s, m[1]] }
+      else
+        items = members
+                .select { |m| (start_id <= m[0]) && (finish_id >= m[0]) }
+                .map { |m| [m[0].to_s, m[1]] }
+      end
       items.reverse! if reversed
       return items.first(opts['count'].to_i) if opts.key?('count')
       items

lib/mock_redis/stream/id.rb

@@ -3,9 +3,10 @@ class Stream
     class Id
       include Comparable
 
-      attr_accessor :timestamp, :sequence
+      attr_accessor :timestamp, :sequence, :exclusive
 
       def initialize(id, min: nil, sequence: 0)
+        @exclusive = false
         case id
         when '*'
           @timestamp = (Time.now.to_f * 1000).to_i
@@ -20,8 +21,12 @@ def initialize(id, min: nil, sequence: 0)
           @timestamp = @sequence = Float::INFINITY
         else
           if id.is_a? String
-            (_, @timestamp, @sequence) = id.match(/^(\d+)-?(\d+)?$/)
-                                           .to_a
+            # See https://redis.io/topics/streams-intro
+            # Ids are a unix timestamp in milliseconds followed by an
+            # optional dash sequence number, e.g. -0. They can also optionally
+            # be prefixed with '(' to change the XRANGE to exclusive.
+            (_, @timestamp, @sequence) = id.match(/^\(?(\d+)-?(\d+)?$/).to_a
+            @exclusive = true if id[0] == '('
             if @timestamp.nil?
               raise Redis::CommandError,
                     'ERR Invalid stream ID specified as stream command argument'

spec/commands/xrange_spec.rb

@@ -79,13 +79,23 @@
       )
     end
 
-    it 'returns entries with both a lower and an upper limit' do
-      expect(@redises.xrange(@key, '1234567891239-0', '1234567891285-0')).to eq(
+    it 'returns entries with both a lower and an upper limit inclusive' do
+      expect(@redises.xrange(@key, '1234567891245-0', '1234567891278-0')).to eq(
         [
           ['1234567891245-0', { 'key2' => 'value2' }],
           ['1234567891245-1', { 'key3' => 'value3' }],
+          ['1234567891278-0', { 'key4' => 'value4' }]
+        ]
+      )
+    end
+
+    it 'returns entries with both a lower and an upper limit exclusive' do
+      expect(@redises.xrange(@key, '(1234567891245-0', '1234567891285-1')).to eq(
+        [
+          # We no longer get '1234567891245-0'
+          ['1234567891245-1', { 'key3' => 'value3' }],
           ['1234567891278-0', { 'key4' => 'value4' }],
-          ['1234567891278-1', { 'key5' => 'value5' }]
+          ['1234567891278-1', { 'key5' => 'value5' }] # Note sequence -1
         ]
       )
     end