Problem with multiValueQueryStringParameters and queryStringParameters when Array are indexed

[throrin19]

Describe the bug
When we try to send Data to our API using query String with indexed array (default in axios), We don't have same thing than non indexed array :

Query parameters without indexed array :

http://localhost:8000?lite=true&measures[]=[%22TE%22,%22lavabo%22]&measures[]=[%22FL%22,%22lavabo%22]&measures[]=[%22VO%22,%22lavabo%22]&measures[]=[%22TE%22,%22lavab%22]

• Result in Middy:
  • queryStringParameters :

    {"lite":"true", "measures[]":"[\"TE\",\"lavab\"]"}
    

  • multiValueQueryStringParameters :

    {"lite":["true"],"measures[]":["[\"TE\",\"lavabo\"]","[\"FL\",\"lavabo\"]","[\"VO\",\"lavabo\"]","[\"TE\",\"lavab\"]"]}
    

Query parameters with indexed array :

http://localhost:8000?lite=true&measures[0][0]=TE&measures[0][1]=lavab&measures[1][0]=VO&measures[1][1]=lavabo

• Result in Middy:
  • queryStringParameters :

    {"lite":"true","measures[0][0]":"TE","measures[0][1]":"lavabo","measures[1][0]":"FL","measures[1][1]":"lavabo" }
    

  • multiValueQueryStringParameters :

    {"lite":["true"],"measures[0][0]":["TE"],"measures[0][1]":["lavabo"],"measures[1][0]":["FL"],"measures[1][1]":["lavabo"]}
    

To Reproduce
How to reproduce the behaviour:

1. Launch a request with non indexed array
2. Launch a request with indexed array

Expected behaviour
Same result between indexed and non indexed array : multiValueQueryStringParameters with correct values.

Environment (please complete the following information):

• Node.js: 20.18.0
• Middy: 5.5.1
• AWS SDK: 3.682.0

Additional context
In local we launch it with serverless-offline

[willfarrell]

Without middy, do you get the expected results from requests to lambda & serverless-offline? As far as I know, middy never modifies multiValueQueryStringParameters.