In VSCode snippets how do you use transform to lowercase just the first letter of a value? - visual-studio-code

Question

I've just started getting into vsCode snippets. They seem really handy.
Is there a way to ensure that what a user entered at a tabstop starts with a lowercase value.
Here's my test case/ sandbox :
"junk": {
"prefix": "junk",
"body": [
"original:${1:type some string here then tab}",
"lower:${1/(.*)/${1:/downcase}/}",
"upper:${1/(.*)/${1:/upcase}/}",
"capitalized:${1/(.*)/${1:/capitalize}/}",
"camel:${1/(.*)/${1:/camelcase}/}",
"pascal:${1/(.*)/${1:/pascalcase}/}",
],
"description": "junk"
}
and here's what it produces:
original:SomeValue
lower:somevalue
upper:SOMEVALUE
capitalized:SomeValue
camel:somevalue
pascal:Somevalue
"camel" is pretty close but I want to preserve the capital if the user entered a camelcase value.
I just want the first character lower no matter what.

Answer 1

The answer is:
${1/(.)(.*)/${1:/downcase}$2/}

Answer 2

Just to clarify, if you look at this commit: https://github.com/microsoft/vscode/commit/3d6389bb336b8ca9b12bc1e772f7056d5c03d3ee
function _toCamelCase(value: string): string {
const match = value.match(/[a-z0-9]+/gi);
console.log(match)
if (!match) {
return value;
}
return match.map((word, index) => {
if (index === 0) {
return word.toLowerCase();
} else {
return word.charAt(0).toUpperCase()
+ word.substr(1).toLowerCase();
}
})
.join('');
}
the camelcase transform is intended for input like
some-value
some_value
some.value
I think any non [a-z0-9]/i will work as the separator between words. So your case of SomeValue is not the intended use of camelcase: according to the function above the entire SomeValue is one match (the match is case-insensitve) and then that entire word is lowercased.