[18.0][FIX] fieldservice_sale: preserve FSM template type

[fsmw]

Fixes #1398

Summary

• Preserve the FSM template on sale-level generated orders when a single template is selected.
• Copy the template's type to the generated FSM order when the selected templates resolve to one type.
• Add regression coverage for sale order confirmation creating an FSM order with template and type.

Verification

• pre-commit run --files fieldservice_sale/models/sale_order.py fieldservice_sale/tests/test_fsm_sale_common.py fieldservice_sale/tests/test_fsm_sale_order.py
• /home/fsmw/dev/smwlab/.venv/bin/python /home/fsmw/dev/smwlab/OCB/odoo-bin --addons-path=/home/fsmw/dev/smwlab/OCB/odoo/addons,/home/fsmw/dev/smwlab/OCB/addons,/home/fsmw/dev/smwlab/oca-fsmw/field-service -d test_fieldservice_sale_template_type_green3 --init=fieldservice_sale --test-enable --stop-after-init --test-tags /fieldservice_sale --http-port=18073

[OCA-git-bot]

Hi @wolfhall, @brian10048, @max3903,
some modules you are maintaining are being modified, check this out!

[fsmw]

The current failing test job is unrelated to this PR's fieldservice_sale changes. I reproduced the fieldservice_kanban_info failures on clean upstream/18.0 and opened a separate targeted fix in #1533.

[fsmw]

CI should now be green after #1533 merged (fixes the upstream date-test flakiness). This is a focused [FIX] preserving FSM template types on SO lines. Ready for review when possible!

[rrebollo]

@fsmw Please do a rebase — the red tests might turn green afterward.

[rrebollo]

Functional and code review: It's working really well.
From a technical perspective, I would personally suggest refactoring to simplify the template_ids approach. Please consider it.

[rrebollo]

I did my research. The template_ids keyword argument is misleading. Look at how it's used: the fsm_order_template_id field on sale.order is a many2one, so it always points to a single record — not many.

If You go this way You would need to refactor almost all the method here.

I might be wrong, so please review and consider this. You could even correct it in

field-service/fieldservice_sale/models/sale_order.py

Lines 102 to 122 in 9560bf6

	def _field_service_generate_sale_fsm_orders(self, new_fsm_sol):
	"""
	Generate the FSM Order for this sale order if it doesn't exist.
	"""
	self.ensure_one()
	new_fsm_orders = self.env["fsm.order"]
	if new_fsm_sol:
	fsm_by_sale = self.env["fsm.order"].search(
	[("sale_id", "=", self.id), ("sale_line_id", "=", False)]
	)
	if not fsm_by_sale:
	templates = new_fsm_sol.product_id.fsm_order_template_id
	vals = self._prepare_fsm_values(
	so_id=self.id, template_ids=templates.ids
	)
	fsm_by_sale = self.env["fsm.order"].sudo().create(vals)
	new_fsm_orders |= fsm_by_sale
	new_fsm_sol.write({"fsm_order_id": fsm_by_sale.id})
	return new_fsm_orders

[rrebollo]

Originally, it was way too complicated for no reason at all.

[rrebollo]

Suggested change

	new_fsm_sol.write({"fsm_order_id": fsm_by_sale.id})
	new_fsm_sol.fsm_order_id = fsm_by_sale.id