Merge pull request #21801 from mattermost/MM-48125-downgrade-to-starter-email-says-upgrade-with-billing-start-date

- Ensure upgrade emails are not sent out when downgrading to the starter/free plan by checking if the new subscription's product SKU is cloud-starter.

api4/cloud.go

@@ -96,6 +96,8 @@ func getSubscription(c *Context, w http.ResponseWriter, r *http.Request) {
 }
 
 func changeSubscription(c *Context, w http.ResponseWriter, r *http.Request) {
+	userId := c.AppContext.Session().UserId
+
 	if !c.App.Channels().License().IsCloud() {
 		c.Err = model.NewAppError("Api4.changeSubscription", "api.cloud.license_error", nil, "", http.StatusInternalServerError)
 		return
@@ -118,13 +120,13 @@ func changeSubscription(c *Context, w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	currentSubscription, appErr := c.App.Cloud().GetSubscription(c.AppContext.Session().UserId)
+	currentSubscription, appErr := c.App.Cloud().GetSubscription(userId)
 	if appErr != nil {
 		c.Err = model.NewAppError("Api4.changeSubscription", "api.cloud.app_error", nil, "", http.StatusInternalServerError).Wrap(appErr)
 		return
 	}
 
-	changedSub, err := c.App.Cloud().ChangeSubscription(c.AppContext.Session().UserId, currentSubscription.ID, subscriptionChange)
+	changedSub, err := c.App.Cloud().ChangeSubscription(userId, currentSubscription.ID, subscriptionChange)
 	if err != nil {
 		c.Err = model.NewAppError("Api4.changeSubscription", "api.cloud.app_error", nil, "", http.StatusInternalServerError).Wrap(err)
 		return
@@ -141,6 +143,11 @@ func changeSubscription(c *Context, w http.ResponseWriter, r *http.Request) {
 		c.Logger.Error("Error finding the new cloud product", mlog.Err(err))
 	}
 
+	if product.SKU == string(model.SkuCloudStarter) {
+		w.Write(json)
+		return
+	}
+
 	isYearly := product.IsYearly()
 
 	// Log failures for purchase confirmation email, but don't show an error to the user so as not to confuse them

model/cloud.go

@@ -42,6 +42,20 @@ const (
 	SubscriptionFamilyOnPrem = SubscriptionFamily("on-prem")
 )
 
+type ProductSku string
+
+const (
+	SkuStarterGov        = ProductSku("starter-gov")
+	SkuProfessionalGov   = ProductSku("professional-gov")
+	SkuEnterpriseGov     = ProductSku("enterprise-gov")
+	SkuStarter           = ProductSku("starter")
+	SkuProfessional      = ProductSku("professional")
+	SkuEnterprise        = ProductSku("enterprise")
+	SkuCloudStarter      = ProductSku("cloud-starter")
+	SkuCloudProfessional = ProductSku("cloud-professional")
+	SkuCloudEnterprise   = ProductSku("cloud-enterprise")
+)
+
 // Product model represents a product on the cloud system.
 type Product struct {
 	ID                string             `json:"id"`