grpcproxy: add unit test for with client auth token

Signed-off-by: Kristoffer Johansson <[email protected]>

Author: krijohs

server/proxy/grpcproxy/util_test.go

@@ -0,0 +1,68 @@
+// Copyright 2025 The etcd 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 grpcproxy
+
+import (
+	"context"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"google.golang.org/grpc/metadata"
+
+	"go.etcd.io/etcd/api/v3/v3rpc/rpctypes"
+)
+
+func TestWithClientAuthToken(t *testing.T) {
+	tests := []struct {
+		name        string
+		initContext func() context.Context
+		want        string
+	}{
+		{
+			name: "with valid token",
+			initContext: func() context.Context {
+				md := metadata.Pairs(rpctypes.TokenFieldNameGRPC, "test-token-123")
+				return metadata.NewIncomingContext(t.Context(), md)
+			},
+			want: "test-token-123",
+		},
+		{
+			name: "without token",
+			initContext: func() context.Context {
+				return t.Context()
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			ctx := t.Context()
+			ctxWithToken := tt.initContext()
+
+			got := withClientAuthToken(ctx, ctxWithToken)
+
+			if tt.want == "" {
+				assert.Equal(t, ctx, got)
+				return
+			}
+
+			md, ok := metadata.FromOutgoingContext(got)
+			assert.True(t, ok)
+			tokens := md[rpctypes.TokenFieldNameGRPC]
+			assert.Len(t, tokens, 1)
+			assert.Equal(t, tt.want, tokens[0])
+		})
+	}
+}