[Feature]: Automatable mode for authentication for theme dev command #695
Description
What area(s) will this request affect?
Theme
What type of change do you want to see?
Substantial change to existing feature
Overview
It would be great if the shopify theme dev command could have a mode that made it easier to include it in a watch-style build script.
This could either be in the form of it taking the --password flag, or another flag to kick off the authentication flow automatically if the user is logged out, skipping the keypress, like Shopify CLI v2, or it accepting SHOPIFY_CLI_THEME_TOKEN, or some other form of authentication token, like the other commands in v3 and like ThemeKit.
Motivation
Currently, shopify theme dev does not accept the --password flag nor does it read the SHOPIFY_CLI_THEME_TOKEN variable from the environment. Additionally, unlike Shopify CLI v2, it does not kick off the authentication flow automatically but instead waits for a keypress from the user.
This makes it challenging to use shopify theme dev in a watch-style continuous build script, as allowing stdin through makes things complicated.
It would be great if the command had an automation-friendly mode.