Improve Config#server_url

- Don't include the db if it's `0`
- Show unix sockets with `unix://` scheme

Author: byroot

lib/redis_client/config.rb

@@ -124,10 +124,17 @@ def ssl_context
 
       def server_url
         if path
-          "#{path}/#{db}"
+          url = "unix://#{path}"
+          if db != 0
+            url = "#{url}?db=#{db}"
+          end
         else
-          "redis#{'s' if ssl?}://#{host}:#{port}/#{db}"
+          url = "redis#{'s' if ssl?}://#{host}:#{port}"
+          if db != 0
+            url = "#{url}/#{db}"
+          end
         end
+        url
       end
 
       private

test/redis_client/config_test.rb

@@ -198,13 +198,13 @@ def test_overriding
     end
 
     def test_server_url
-      assert_equal "redis://localhost:6379/0", Config.new.server_url
-      assert_equal "redis://localhost:6379/0", Config.new(username: "george", password: "hunter2").server_url
+      assert_equal "redis://localhost:6379", Config.new.server_url
+      assert_equal "redis://localhost:6379", Config.new(username: "george", password: "hunter2").server_url
       assert_equal "redis://localhost:6379/5", Config.new(db: 5).server_url
-      assert_equal "redis://example.com:8080/0", Config.new(host: "example.com", port: 8080).server_url
-      assert_equal "rediss://localhost:6379/0", Config.new(ssl: true).server_url
+      assert_equal "redis://example.com:8080", Config.new(host: "example.com", port: 8080).server_url
+      assert_equal "rediss://localhost:6379", Config.new(ssl: true).server_url
 
-      assert_equal "/var/redis/redis.sock/5", Config.new(path: "/var/redis/redis.sock", db: 5).server_url
+      assert_equal "unix:///var/redis/redis.sock?db=5", Config.new(path: "/var/redis/redis.sock", db: 5).server_url
     end
 
     def test_custom_field

test/redis_client/connection_test.rb

@@ -319,7 +319,7 @@ def test_protocol_error
         new_client(host: "127.0.0.1", port: port).call("PING")
       end
 
-      assert_match(%r{ \(rediss?://127.0.0.1:#{port}/0\)$}, error.message)
+      assert_match(%r{ \(rediss?://127.0.0.1:#{port}\)$}, error.message)
     ensure
       server_thread&.kill
     end
@@ -386,7 +386,7 @@ def test_reconnect_on_readonly
         client.call("SET", "foo", "bar")
       end
       refute_predicate client, :connected?
-      assert_match(%r{ \(rediss?://127.0.0.1:#{port}/0\)$}, error.message)
+      assert_match(%r{ \(rediss?://127.0.0.1:#{port}\)$}, error.message)
     ensure
       server_thread&.kill
     end

test/redis_client_test.rb

@@ -127,7 +127,7 @@ def test_measure_round_trip_delay
   end
 
   def test_server_url
-    assert_equal "redis://#{Servers::HOST}:#{Servers::REDIS_TCP_PORT}/0", @redis.server_url
+    assert_equal "redis://#{Servers::HOST}:#{Servers::REDIS_TCP_PORT}", @redis.server_url
   end
 
   def test_timeout