entc/gen: add support for WithNamed<E> feature-flag (#2792)

* entc/gen: struct fields and methods for NamedEdge api

* entc/gen: generate WithNamedEdge methods for named-edges

* entc/gen: implement eager-loading for named-edges

* entc/gen: simplify eager-loading template

* entc/gen: drop support for unqiue edges in named-based loading

* all: codegen

* doc/website: named-edges feature-flag

* Update doc/md/eager-load.mdx

* Update doc/md/eager-load.mdx

examples/privacytenant/ent/group.go

@@ -45,8 +45,7 @@ type GroupEdges struct {
 func (e GroupEdges) TenantOrErr() (*Tenant, error) {
 	if e.loadedTypes[0] {
 		if e.Tenant == nil {
-			// The edge tenant was loaded in eager-loading,
-			// but was not found.
+			// Edge was loaded but was not found.
 			return nil, &NotFoundError{label: tenant.Label}
 		}
 		return e.Tenant, nil

examples/privacytenant/ent/group_query.go

@@ -31,7 +31,6 @@ type GroupQuery struct {
 	order      []OrderFunc
 	fields     []string
 	predicates []predicate.Group
-	// eager-loading edges.
 	withTenant *TenantQuery
 	withUsers  *UserQuery
 	// intermediate query (i.e. traversal path).

examples/privacytenant/ent/user.go

@@ -48,8 +48,7 @@ type UserEdges struct {
 func (e UserEdges) TenantOrErr() (*Tenant, error) {
 	if e.loadedTypes[0] {
 		if e.Tenant == nil {
-			// The edge tenant was loaded in eager-loading,
-			// but was not found.
+			// Edge was loaded but was not found.
 			return nil, &NotFoundError{label: tenant.Label}
 		}
 		return e.Tenant, nil

examples/privacytenant/ent/user_query.go

@@ -31,7 +31,6 @@ type UserQuery struct {
 	order      []OrderFunc
 	fields     []string
 	predicates []predicate.User
-	// eager-loading edges.
 	withTenant *TenantQuery
 	withGroups *GroupQuery
 	// intermediate query (i.e. traversal path).