tarantool> t = require('tap').test('123')
TAP version 13
---
...

tarantool> t:is_deeply({a = box.NULL}, {})
ok - nil
---
- true
...

tarantool> t:is_deeply({}, {a = box.NULL})
not ok - nil
  ---
  filename: builtin/box/console.lua
  trace:
  - line: -1
    source: =[C]
    filename: eval
    what: C
    namewhat: global
    name: pcall
    src: '[C]'
  - line: 130
    source: '@builtin/box/console.lua'
    filename: builtin/box/console.lua
    what: Lua
    namewhat: method
    name: eval
    src: builtin/box/console.lua
  - line: 395
    source: '@builtin/box/console.lua'
    filename: builtin/box/console.lua
    what: Lua
    namewhat: upvalue
    name: repl
    src: builtin/box/console.lua
  - line: 440
    source: '@builtin/box/console.lua'
    filename: builtin/box/console.lua
    what: Lua
    namewhat: 
    src: builtin/box/console.lua
  line: 440
  expected: key a
  got: nil
  ...
---
- false
...