You may have both stable and insiders releases of Visual Studio Code installed. If you're like me, you'll end up trying to open a file with the code command when you meant code-insiders. This little edit makes it so that the code script knows that and opens it in the right place for you.

1. Make sure to have installed the code and code-insiders command into your path by using the command palette
2. Edit the code command (e.g. code "$(which code)")
3. Add the following to the script, after the remote terminal handling but before everything else:

IS_VS_CODE_RUNNING="$(test "$(ps aux | grep "/[A]pplications/Visual Studio Code.app/Contents/MacOS/Electron")" && echo 1 || echo 0)"
IS_VS_CODE_INSIDERS_RUNNING="$(test "$(ps aux | grep "/[A]pplications/Visual Studio Code - Insiders.app/Contents/MacOS/Electron")" && echo 1 || echo 0)"

if [ $IS_VS_CODE_RUNNING -eq 0 ] && [ $IS_VS_CODE_INSIDERS_RUNNING -eq 1 ]; then
	# VS Code Insiders is running, so let's open it in there.
	code-insiders "$@"
	exit $?
fi

Now, if you are only running the Insiders version of Visual Studio Code, using the code command will be equivalent to running code-insiders.