blob: a9b23e46275d3f6232424afd06ba6c10c60e76ba [file] [log] [blame]
// Copyright 2020 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build !disable_events
package event_test
import (
"context"
"fmt"
"testing"
"github.com/google/go-cmp/cmp"
"golang.org/x/exp/event"
"golang.org/x/exp/event/keys"
)
func TestClone(t *testing.T) {
var labels []event.Label
for i := 0; i < 5; i++ { // one greater than len(Builder.labels)
labels = append(labels, keys.Int(fmt.Sprintf("l%d", i)).Of(i))
}
ctx := event.WithExporter(context.Background(), event.NewExporter(nil))
b1 := event.To(ctx)
b1.With(labels[0]).With(labels[1])
check(t, b1, labels[:2])
b2 := b1.Clone()
check(t, b1, labels[:2])
check(t, b2, labels[:2])
b2.With(labels[2])
check(t, b1, labels[:2])
check(t, b2, labels[:3])
// Force a new backing array for b.Event.Labels.
for i := 3; i < len(labels); i++ {
b2.With(labels[i])
}
check(t, b1, labels[:2])
check(t, b2, labels)
b2.Log("") // put b2 back in the pool.
b2 = event.To(ctx)
check(t, b1, labels[:2])
check(t, b2, []event.Label{})
b2.With(labels[3]).With(labels[4])
check(t, b1, labels[:2])
check(t, b2, labels[3:5])
}
func check(t *testing.T, b event.Builder, want []event.Label) {
t.Helper()
if got := b.Event().Labels; !cmp.Equal(got, want, cmp.Comparer(valueEqual)) {
t.Fatalf("got %v, want %v", got, want)
}
}
func valueEqual(l1, l2 event.Value) bool {
return fmt.Sprint(l1) == fmt.Sprint(l2)
}
func TestTraceBuilder(t *testing.T) {
// Verify that the context returned from the handler is also returned from Start,
// and is the context passed to End.
ctx := event.WithExporter(context.Background(), event.NewExporter(&testTraceHandler{t}))
ctx, end := event.To(ctx).Start("s")
val := ctx.Value("x")
if val != 1 {
t.Fatal("context not returned from Start")
}
end()
}
type testTraceHandler struct {
t *testing.T
}
func (*testTraceHandler) Start(ctx context.Context, _ *event.Event) context.Context {
return context.WithValue(ctx, "x", 1)
}
func (t *testTraceHandler) End(ctx context.Context, _ *event.Event) {
val := ctx.Value("x")
if val != 1 {
t.t.Fatal("Start context not passed to End")
}
}