Recommend to unset associative array variable before declaration to avoid conversion

[pothos]

For new checks and feature suggestions

• https://www.shellcheck.net/ (i.e. the latest commit) currently gives no useful warnings about this
• [ x I searched through https://github.com/koalaman/shellcheck/issues and didn't find anything related

Here's a snippet or screenshot that shows the problem:

#!/bin/bash
myarr="z"
declare -A myarr
myarr[a]=x
echo "${!myarr[@]}"
echo "${myarr[@]}"

This outputs

0 a
z x

because myarr is converted from a string z to having (0, z) as key-value pair

Here's what shellcheck currently says:

nothing

Here's what I wanted or expected to see:

recommendation: use 'unset' before 'declare' to avoid conversion of existing variable contents