You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: service_invocation_test.go
    path of file: ./repos/dapr/tests/e2e/service_invocation
    
    the code of the file until where you have to start completion: //go:build e2e
// +build e2e

/*
Copyright 2021 The Dapr 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 serviceinvocation_tests

import (
	"encoding/base64"
	"encoding/json"
	"fmt"
	"net/http"
	"os"
	"strings"
	"testing"

	guuid "github.com/google/uuid"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"

	diag "github.com/dapr/dapr/pkg/
    
func TestUppercaseMiddlewareServiceInvocation(t *testing.T) {
	testFn := func(targetApp string) func(t *testing.T) {
		return func(t *testing.T) {
			externalURL := tr.Platform.AcquireAppExternalURL(targetApp)
			require.NotEmpty(t, externalURL, "external URL must not be empty!")

			// This initial probe makes the test wait a little bit longer when needed,
			// making this test less flaky due to delays in the deployment.
			_, err := utils.HTTPGetNTimes(externalURL, numHealthChecks)
			require.NoError(t, err)

			t.Run("uppercase middleware should be applied", func(t *testing.T) {
				testMessage := guuid.New().String()
				body, err := json.Marshal(testCommandRequest{
					RemoteApp: "serviceinvocation-callee-2",
					Method:    "httptohttptest",
					Message:   &testMessage,
				})
				require.NoError(t, err)

				resp, err := utils.HTTPPost(
					fmt.Sprintf("%s/httptohttptest", externalURL), body)
				t.Log("checking err...")
				require.NoError(t, err)

				var appResp appResponse
				t.Logf("unmarshalling..%s\n", string(resp))
				err = json.Unmarshal(resp, &appResp)
				require.NoError(t, err)

				uppercaseMsg := strings.ToUpper(testMessage)
				require.Contains(t, appResp.Message, uppercaseMsg)
			})
		}
	}

	t.Run("serviceinvocation-caller", testFn("serviceinvocation-caller"))
}