Converting Bash Option String to Unix Environment Variable Name using vscode snippet Transformation

I am working on a bash script snippet for the sheller extension where I need to convert a Bash option string entered by the user into a valid Unix environment variable name. For example, the user may enter an option string like "-my-option-name" or "--another_option=", and I need to transform it into a valid environment variable name like "MY_OPTION_NAME" or "ANOTHER_OPTION".

To clarify my requirements and provide a clear understanding of the desired transformation, I have created a JavaScript example on JSFiddle. You can find it here. The example showcases a table of different input strings and their expected output after the transformation.

The javascript function handling the transformation used in the fiddle.

function stripCapitalizeAndSnake(inputString) {
  const regex = /^-+(.*?)(?:=)?$/;
  const result = inputString.replace(regex, (_, selectedString) => {
    const transformedString = selectedString.replace(/-/g, '_');
    return transformedString.toUpperCase();
  });
  return result;
}

I am seeking guidance or preferably code examples on how to implement this transformation using snippet transforms in Visual Studio Code snippets.

> Thank you in advance for your assistance, especially if you have experience or knowledge about the vscode, code snippets and transformations!

Here is a simplified version of a snippet, which I hope someone can modify for the expected result.

Current snippet

{
    "OPTION TO ENVIRONMENT": {
        "prefix": "option to environment",
        "body": [
            "#!/usr/bin/env bash",
            "",
            "OPTION=\"${1:--quiet-mode}\"",
            "",
            "echo \"Option        :\${OPTION}\"",
            "echo \"Variable name :${1/^(\\-+)([^=]+)(=)?$/${2:/upcase}/}\""
        ],
        "description": "Convert bash option to a valid shell environment variable"
    }
}

Current Result

When triggering the snippet, and leaving the default value as is the Variable name is correct except for the fact that "-" is not replaced with "_" which is my problem.
"QUIET-MODE" needs to be transformed to "QUIET_MODE".

#!/usr/bin/env bash

OPTION="--quiet-mode"

echo "Option        :${OPTION}"
echo "Variable name :QUIET-MODE"

I have been trying to do this for a while now, so I ask you, do you know how to do this?

Ps.
Do you know of a better documentation about transformations, other than is mentioned here?

use the extension Hypersnips

you can add JavaScript to the snippet

It can be done with VSC standard snippets

• capture possible starting - characters, ignore in result
• capture all till - or =, UPCASE that group
• capture possible -, substitute with _
• capture possible =, ignore in result

apply these rules global/repeatedly

{
  "OPTION TO ENVIRONMENT": {
    "prefix": "option to environment",
    "body": [
        "#!/usr/bin/env bash",
        "",
        "OPTION=\"${1:--quiet-mode}\"",
        "",
        "echo \"Option        :\${OPTION}\"",
        "echo \"Variable name :${1/(^-+)?([^-=]+)(-?)(=?)/${2:/upcase}${3:+_}/g}\""
    ],
    "description": "Convert bash option to a valid shell environment variable"
}