From 959602c6ccae03d4f0f15cef5ab1ded6c6d2300f Mon Sep 17 00:00:00 2001
From: "Thomas, Jason" <jmthomas@ball.com>
Date: Wed, 24 Jun 2020 09:32:27 -0600
Subject: [PATCH 1/3] XADD maxlen 0 creates empty stream

---
 lib/mock_redis/stream.rb   | 6 +++++-
 spec/commands/xadd_spec.rb | 6 ++++++
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/lib/mock_redis/stream.rb b/lib/mock_redis/stream.rb
index 05b3f269..2848813c 100644
--- a/lib/mock_redis/stream.rb
+++ b/lib/mock_redis/stream.rb
@@ -37,7 +37,11 @@ def add(id, values)
     def trim(count)
       deleted = @members.size - count
       if deleted > 0
-        @members = @members.to_a[-count..-1].to_set
+        if count == 0
+          @members = Set.new
+        else
+          @members = @members.to_a[-count..-1].to_set
+        end
         deleted
       else
         0
diff --git a/spec/commands/xadd_spec.rb b/spec/commands/xadd_spec.rb
index 14f2336e..7d993c51 100644
--- a/spec/commands/xadd_spec.rb
+++ b/spec/commands/xadd_spec.rb
@@ -112,4 +112,10 @@
       ]
     )
   end
+
+  it 'creates an empty stream with maxlen of 0' do
+    @redises.xadd(@key, { key: 'value' }, maxlen: 0)
+    expect(@redises.xlen(@key)).to eq 0
+    expect(@redises.xrange(@key, '-', '+')).to eq([])
+  end
 end

From 0997dad3725713a50dd07efb19b90d383d0cacf0 Mon Sep 17 00:00:00 2001
From: "Thomas, Jason" <jmthomas@ball.com>
Date: Wed, 24 Jun 2020 09:36:26 -0600
Subject: [PATCH 2/3] Rubocop

---
 lib/mock_redis/stream.rb | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/lib/mock_redis/stream.rb b/lib/mock_redis/stream.rb
index 2848813c..5cce8298 100644
--- a/lib/mock_redis/stream.rb
+++ b/lib/mock_redis/stream.rb
@@ -37,11 +37,11 @@ def add(id, values)
     def trim(count)
       deleted = @members.size - count
       if deleted > 0
-        if count == 0
-          @members = Set.new
-        else
-          @members = @members.to_a[-count..-1].to_set
-        end
+        @members = if count == 0
+                     Set.new
+                   else
+                     @members.to_a[-count..-1].to_set
+                   end
         deleted
       else
         0

From df27aac15137028e481ac78b87053715215d0b26 Mon Sep 17 00:00:00 2001
From: "Thomas, Jason" <jmthomas@ball.com>
Date: Wed, 24 Jun 2020 15:13:55 -0600
Subject: [PATCH 3/3] Ignore emptry streams on cleanup

---
 lib/mock_redis/utility_methods.rb |  2 +-
 spec/commands/del_spec.rb         | 15 +++++++++++++++
 spec/commands/xadd_spec.rb        |  1 +
 3 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/lib/mock_redis/utility_methods.rb b/lib/mock_redis/utility_methods.rb
index 4e7238b4..47f18493 100644
--- a/lib/mock_redis/utility_methods.rb
+++ b/lib/mock_redis/utility_methods.rb
@@ -18,7 +18,7 @@ def primitive?(value)
     end
 
     def clean_up_empties_at(key)
-      if data[key]&.empty? && data[key] != ''
+      if data[key]&.empty? && data[key] != '' && !data[key].is_a?(Stream)
         del(key)
       end
     end
diff --git a/spec/commands/del_spec.rb b/spec/commands/del_spec.rb
index 27b15daa..36816314 100644
--- a/spec/commands/del_spec.rb
+++ b/spec/commands/del_spec.rb
@@ -1,6 +1,14 @@
 require 'spec_helper'
 
 describe '#del(key [, key, ...])' do
+  before :all do
+    sleep 1 - (Time.now.to_f % 1)
+  end
+
+  before :each do
+    @redises._gsub(/\d{3}-\d/, '...-.')
+  end
+
   it 'returns the number of keys deleted' do
     @redises.set('mock-redis-test:1', 1)
     @redises.set('mock-redis-test:2', 1)
@@ -32,4 +40,11 @@
   it 'raises an error if an empty array is given' do
     expect { @redises.del [] }.to raise_error Redis::CommandError
   end
+
+  it 'removes a stream key' do
+    @redises.xadd('mock-redis-stream', { key: 'value' }, maxlen: 0)
+    expect(@redises.exists?('mock-redis-stream')).to eq true
+    @redises.del('mock-redis-stream')
+    expect(@redises.exists?('mock-redis-stream')).to eq false
+  end
 end
diff --git a/spec/commands/xadd_spec.rb b/spec/commands/xadd_spec.rb
index 7d993c51..5e204779 100644
--- a/spec/commands/xadd_spec.rb
+++ b/spec/commands/xadd_spec.rb
@@ -117,5 +117,6 @@
     @redises.xadd(@key, { key: 'value' }, maxlen: 0)
     expect(@redises.xlen(@key)).to eq 0
     expect(@redises.xrange(@key, '-', '+')).to eq([])
+    expect(@redises.exists?(@key)).to eq true
   end
 end