Feature/add constrain to spa

This is the link to the Trello card

energy_selfconsumption/models/supply_point_assignation.py

-from odoo import fields, models, api
+from odoo import api, fields, models,  _
 from odoo.exceptions import ValidationError
 
 
 class SupplyPointAssignation(models.Model):
-    _name = 'energy_selfconsumption.supply_point_assignation'
-    _description = 'Supply Point Assignation'
+    _name = "energy_selfconsumption.supply_point_assignation"
+    _description = "Supply Point Assignation"
 
-    @api.depends('distribution_table_id')
+    @api.depends("distribution_table_id")
     def _compute_supply_point_filtered_ids(self):
         '''
         List of supply point of partners subscribed to the project and not in the list of the distribution table to
@@ -16,9 +16,10 @@ class SupplyPointAssignation(models.Model):
         '''
         for record in self:
             record.supply_point_filtered_ids = \
-                record.distribution_table_id.selfconsumption_project_id.inscription_ids.mapped('partner_id.supply_ids') \
-                    .filtered_domain([('id', 'not in', record.distribution_table_id.supply_point_assignation_ids.mapped(
-                    'supply_point_id.id'))])
+                record.distribution_table_id.selfconsumption_project_id.inscription_ids.mapped("partner_id.supply_ids") \
+                    .filtered_domain([("id", "not in", record.distribution_table_id.supply_point_assignation_ids.mapped(
+                    "supply_point_id.id"))])
+
 
     distribution_table_id = fields.Many2one(
         "energy_selfconsumption.distribution_table", required=True
@@ -41,18 +42,21 @@ class SupplyPointAssignation(models.Model):
         related="distribution_table_id.coefficient_is_valid"
     )
 
-    supply_point_filtered_ids = fields.One2many('energy_selfconsumption.supply_point',
+
+    supply_point_filtered_ids = fields.One2many("energy_selfconsumption.supply_point",
                                                 compute=_compute_supply_point_filtered_ids, readonly=True)
     company_id = fields.Many2one(
         "res.company", default=lambda self: self.env.company, readonly=True
     )
-    @api.constrains('coefficient')
+    @api.constrains("coefficient", "owner_id")
     def constraint_coefficient(self):
         for record in self:
+            if record.owner_id and not record.owner_id.member:
+                raise ValidationError(_("The selected partner is not a member"))
             if record.coefficient < 0:
-                raise ValidationError("Coefficient can't be negative.")
+                raise ValidationError(_("Coefficient can't be negative."))
 
-    @api.onchange('coefficient')
+    @api.onchange("coefficient")
     def _onchange_coefficient(self):
         if self.coefficient < 0:
             self.coefficient = -self.coefficient