Test Exemplars and CardinalityLimit

sdk/metric/internal/x/x_test.go

@@ -0,0 +1,94 @@
+// 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 x
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestExemplars(t *testing.T) {
+	const key = "OTEL_GO_X_EXEMPLAR"
+	require.Equal(t, key, Exemplars.Key())
+
+	t.Run("true", func(t *testing.T) {
+		t.Setenv(key, "true")
+		assert.True(t, Exemplars.Enabled())
+
+		v, ok := Exemplars.Lookup()
+		assert.True(t, ok)
+		assert.Equal(t, "true", v)
+	})
+
+	t.Run("false", func(t *testing.T) {
+		t.Setenv(key, "false")
+		assert.False(t, Exemplars.Enabled())
+
+		v, ok := Exemplars.Lookup()
+		assert.False(t, ok)
+		assert.Equal(t, "", v)
+	})
+
+	t.Run("empty", func(t *testing.T) {
+		assert.False(t, Exemplars.Enabled())
+
+		v, ok := Exemplars.Lookup()
+		assert.False(t, ok)
+		assert.Equal(t, "", v)
+	})
+}
+
+func TestCardinalityLimit(t *testing.T) {
+	const key = "OTEL_GO_X_CARDINALITY_LIMIT"
+	require.Equal(t, key, CardinalityLimit.Key())
+
+	t.Run("100", func(t *testing.T) {
+		t.Setenv(key, "100")
+		assert.True(t, CardinalityLimit.Enabled())
+
+		v, ok := CardinalityLimit.Lookup()
+		assert.True(t, ok)
+		assert.Equal(t, 100, v)
+	})
+
+	t.Run("-1", func(t *testing.T) {
+		t.Setenv(key, "-1")
+		assert.True(t, CardinalityLimit.Enabled())
+
+		v, ok := CardinalityLimit.Lookup()
+		assert.True(t, ok)
+		assert.Equal(t, -1, v)
+	})
+
+	t.Run("false", func(t *testing.T) {
+		t.Setenv(key, "false")
+		assert.False(t, CardinalityLimit.Enabled())
+
+		v, ok := CardinalityLimit.Lookup()
+		assert.False(t, ok)
+		assert.Equal(t, 0, v)
+	})
+
+	t.Run("empty", func(t *testing.T) {
+		t.Setenv(key, "false")
+		assert.False(t, CardinalityLimit.Enabled())
+
+		v, ok := CardinalityLimit.Lookup()
+		assert.False(t, ok)
+		assert.Equal(t, 0, v)
+	})
+}