Remove the extension of filename and convert camelCase to snake case using regex vscode snippets?

Question

I need to create many files on same structure. The modules exported and filename have some relation. I have to convert. Example input and outputs.

startNewGame.ts => start-new-game
gameOver.ts => game-over
ALongNameForAFile.ts=> a-long-name-for-file
short.ts => short

My current regex is

${TM_FILENAME/([A-Z])/-${1:/downcase}/g}

For now I am only able to remove change capital letter so small and add -. There are two problems

• I am unable to remove .ts
• There is extra - in the start.

Note: I am using this in vscode snippets

Answer 1

You were close on removing the file name extension: use TM_FILENAME_BASE instead. See vscode snippet variables.

"filename change": {
  "prefix": "_co",
  "body": [
    "${TM_FILENAME_BASE/(^[A-Z])|([A-Z])/${2:+-}${2:/downcase}${1:/downcase}/g}",
  ],
  "description": ""
},

Since the leading - only happens when there is a capital letter at the start, I found it easiest to handle that case separately. So the regex is now:

(^[A-Z])|([A-Z]) // the order is important.

${2:+-} is a conditional, add the - only if there is a capture group 2.