AppleScript to create a new file in Finder (to be used in Automator)

automator_new_file.scpt

-- AppleScript to create a new file in Finder
--
-- Use it in Automator, with the following configuration:
-- - Service receives: no input
-- - In: Finder.app
--
-- References:
--  - http://apple.stackexchange.com/a/129702
--  - http://stackoverflow.com/a/6125252/2530295
--  - http://www.russellbeattie.com/blog/fun-with-the-os-x-finder-and-applescript
--
-- Know bugs
-- - When create/delete in desktop, after some time, the file is showed again and after deleted (it works, but it's strange)

set file_name to "untitled"
set file_ext to ".txt"
set is_desktop to false

-- get folder path and if we're in desktop (no folder opened)
try
    tell application "Finder"
        set this_folder to (folder of the front Finder window) as alias
    end tell
on error
    -- no open folder windows
    set this_folder to path to desktop folder as alias
    set is_desktop to true
end try

-- get the new file name (do not override an already existing file)
tell application "System Events"
    set file_list to get the name of every disk item of this_folder
end tell
set new_file to file_name & file_ext
set x to 1
repeat
    if new_file is in file_list then
        set new_file to file_name & " " & x & file_ext
        set x to x + 1
    else
        exit repeat
    end if
end repeat

-- create and select the new file
tell application "Finder"
    
    activate
    set the_file to make new file at folder this_folder with properties {name:new_file}
    if is_desktop is false then
        reveal the_file
    else
        select window of desktop
        set selection to the_file
        delay 0.1
    end if
end tell

-- press enter (rename)
tell application "System Events"
    tell process "Finder"
        keystroke return
    end tell
end tell

Open Automator and create a Service;

There is no "Service" in Catalina, but there is a "Quick Action"

The version to open file in default text editor.

-- AppleScript to create a new file in Finder
--
-- Use it in Automator, with the following configuration:
-- - Service receives: no input
-- - In: Finder.app
--
-- References:
--  - http://apple.stackexchange.com/a/129702
--  - http://stackoverflow.com/a/6125252/2530295
--  - http://www.russellbeattie.com/blog/fun-with-the-os-x-finder-and-applescript
--
-- Know bugs
-- - When create/delete in desktop, after some time, the file is showed again and after deleted (it works, but it's strange)

set file_name to "untitled"
set file_ext to ".txt"
set is_desktop to false

-- get folder path and if we're in desktop (no folder opened)
try
    tell application "Finder"
        set this_folder to (folder of the front Finder window) as alias
    end tell
on error
    -- no open folder windows
    set this_folder to path to desktop folder as alias
    set is_desktop to true
end try

-- get the new file name (do not override an already existing file)
tell application "System Events"
    set file_list to get the name of every disk item of this_folder
end tell
set new_file to file_name & file_ext
set x to 1
repeat
    if new_file is in file_list then
        set new_file to file_name & " " & x & file_ext
        set x to x + 1
    else
        exit repeat
    end if
end repeat

-- create and select the new file
tell application "Finder"
    
    activate
    set the_file to make new file at folder this_folder with properties {name:new_file}
    if is_desktop is false then
        reveal the_file
		delay 0.1
        open the_file
    else
        select window of desktop
        set selection to the_file
        delay 0.1
    end if
end tell

Add delay 0.3 line after reveal the_file to fix rename focus for newest macOS. You also need to allow Finder in security setings for Accessibility tab.