opentelemetry-go/api/label/iterator_test.go

// Copyright The OpenTelemetry Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package label_test

import (
	"testing"

	"github.com/stretchr/testify/require"

	"go.opentelemetry.io/otel/api/key"
	"go.opentelemetry.io/otel/api/label"
)

func TestIterator(t *testing.T) {
	one := key.String("one", "1")
	two := key.Int("two", 2)
	lbl := label.NewSet(one, two)
	iter := lbl.Iter()
	require.Equal(t, 2, iter.Len())

	require.True(t, iter.Next())
	require.Equal(t, one, iter.Label())
	idx, attr := iter.IndexedLabel()
	require.Equal(t, 0, idx)
	require.Equal(t, one, attr)
	require.Equal(t, 2, iter.Len())

	require.True(t, iter.Next())
	require.Equal(t, two, iter.Label())
	idx, attr = iter.IndexedLabel()
	require.Equal(t, 1, idx)
	require.Equal(t, two, attr)
	require.Equal(t, 2, iter.Len())

	require.False(t, iter.Next())
	require.Equal(t, 2, iter.Len())
}

func TestEmptyIterator(t *testing.T) {
	lbl := label.NewSet()
	iter := lbl.Iter()
	require.Equal(t, 0, iter.Len())
	require.False(t, iter.Next())
}