TECH-15245: alias unpack to table.unpack

CHANGELOG.md

@@ -4,6 +4,10 @@ Inspired by [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 Note: this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.3.1] - not released
+### Added
+- Added support for `unpack` as an alias for `table.unpack` to ensure compatability for old lua scripts running on new lua versions (> 5.1).
+
 ## [0.3.0] - 2024-10-15
 ### Changed
 - Use Digest::SHA1 instead of Digest::SHA256 for hex_digest.

Gemfile.lock

@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    mock_redis_lua_extension2 (0.3.0)
+    mock_redis_lua_extension2 (0.3.1.pre.0)
       mock_redis
       rufus-lua
 
@@ -10,7 +10,7 @@ GEM
   specs:
     coderay (1.1.3)
     diff-lcs (1.3)
-    ffi (1.17.0)
+    ffi (1.17.1)
     method_source (1.1.0)
     mock_redis (0.28.0)
       ruby2_keywords

lib/mock_redis_lua_extension.rb

@@ -82,6 +82,8 @@ def eval(script, keys=nil, argv=nil, **args)
     lua_state = Rufus::Lua::State.new
     setup_keys_and_argv(lua_state, keys, argv, args)
 
+    lua_state.eval('unpack = table.unpack')
+
     lua_state.function 'redis.call' do |cmd, *args|
       lua_bound_redis_call(cmd, *args)
     end

lib/mock_redis_lua_extension/version.rb

@@ -1,3 +1,3 @@
 module MockRedisLuaExtension
-  VERSION = "0.3.0".freeze
+  VERSION = "0.3.1.pre.0".freeze
 end

spec/mock_redis_lua_extension_spec.rb

@@ -75,6 +75,19 @@
         result = redis.eval('return KEYS[1]', keys: [:stuff])
         expect(result).to eq('stuff')
       end
+
+      it 'supports the unpack function, as equivalent to table.unpack' do
+        unpack_lua_script = '
+          local t = {1, 2, 3, 4, 5}
+          return {unpack(t, 2, 4)}
+        '.strip
+        table_unpack_lua_script = '
+          local t = {1, 2, 3, 4, 5}
+          return {table.unpack(t, 2, 4)}
+        '.strip
+        expect(redis.eval(unpack_lua_script)).to eq([2, 3, 4])
+        expect(redis.eval(table_unpack_lua_script)).to eq([2, 3, 4])
+      end
     end
 
     context 'marshalling lua args to redis.call' do