test(x/perp): Include checks for the queryResp.MarginRatioIndex in 'TestOpenPositionsAndCloseCmd'.

[Unique-Divine]

The Problem

A missing sdk.Dec field doesn't appear as a blank string; It ends up becoming zero, which can be misleading. Here's an example response from when a trader opened and then closed the position on a test chain.

{
  "block_number": 2830, 
  "margin_ratio_index": 0.0, 
  "margin_ratio_mark": 0.1, 
  "position": {
    "block_number": 2830, 
    "last_update_cumulative_premium_fraction": -174.20833333320226, 
    "margin": 1.0, 
    "open_notional": 10.0, 
    "pair": {"token0": "ubtc", "token1": "unusd"}, 
    "size": 0.000499999999999835, 
    "trader_address": "nibi1htxgm8eapmt23cmrh22lx4yy2ghfy8kkhsg8qr"},     
    "position_notional": 10.0, 
    "unrealized_pnl": 0.0
}

Notice that the margin ratio based on the index price, margin_ratio_index is zero because the test was run without a price feed.

How to Fix it - set gogoproto.nullable to true

According to the Protocol Buffer specification, you should be able to tell whether a field is set or unset. With the option nullable=false this feature is lost, since your non-nullable fields will always be set. It can be seen as a layer on top of Protocol Buffers, where before and after marshalling all non-nullable fields are set and they cannot be unset. - https://pkg.go.dev/github.com/gogo/protobuf/gogoproto

Tasks

• Fix this
• Test the fix