examples: make examples testable

examples/o2obidi/example_test.go

@@ -0,0 +1,85 @@
+// Copyright 2019-present Facebook Inc. All rights reserved.
+// This source code is licensed under the Apache 2.0 license found
+// in the LICENSE file in the root directory of this source tree.
+
+package main
+
+import (
+	"context"
+	"fmt"
+	"log"
+
+	"github.com/facebookincubator/ent/examples/o2obidi/ent"
+	"github.com/facebookincubator/ent/examples/o2obidi/ent/user"
+
+	_ "github.com/mattn/go-sqlite3"
+)
+
+func Example_O2OBidi() {
+	client, err := ent.Open("sqlite3", "file:ent?mode=memory&cache=shared&_fk=1")
+	if err != nil {
+		log.Fatalf("failed opening connection to sqlite: %v", err)
+	}
+	defer client.Close()
+	ctx := context.Background()
+	// Run the auto migration tool.
+	if err := client.Schema.Create(ctx); err != nil {
+		log.Fatalf("failed creating schema resources: %v", err)
+	}
+	if err := Do(ctx, client); err != nil {
+		log.Fatal(err)
+	}
+	// Output:
+	// a8m
+	// nati
+	// 2
+	// nati
+}
+
+func Do(ctx context.Context, client *ent.Client) error {
+	a8m, err := client.User.
+		Create().
+		SetAge(30).
+		SetName("a8m").
+		Save(ctx)
+	if err != nil {
+		return fmt.Errorf("creating user: %v", err)
+	}
+	nati, err := client.User.
+		Create().
+		SetAge(28).
+		SetName("nati").
+		SetSpouse(a8m).
+		Save(ctx)
+	if err != nil {
+		return fmt.Errorf("creating user: %v", err)
+	}
+
+	// Query the spouse edge.
+	// Unlike `Only`, `OnlyX` panics if an error occurs.
+	spouse := nati.QuerySpouse().OnlyX(ctx)
+	fmt.Println(spouse.Name)
+	// Output: a8m
+
+	spouse = a8m.QuerySpouse().OnlyX(ctx)
+	fmt.Println(spouse.Name)
+	// Output: nati
+
+	// Query how many users have a spouse.
+	// Unlike `Count`, `CountX` panics if an error occurs.
+	count := client.User.
+		Query().
+		Where(user.HasSpouse()).
+		CountX(ctx)
+	fmt.Println(count)
+	// Output: 2
+
+	// Get the user, that has a spouse with name="a8m".
+	spouse = client.User.
+		Query().
+		Where(user.HasSpouseWith(user.Name("a8m"))).
+		OnlyX(ctx)
+	fmt.Println(spouse.Name)
+	// Output: nati
+	return nil
+}