test(internal/authflow): assert user-agent header is not modified/added

Signed-off-by: Babak K. Shandiz <babakks@github.com>

Author: babakks

internal/authflow/flow_test.go

@@ -10,34 +10,28 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
-func Test_getViewer_preservesUserAgent(t *testing.T) {
+func Test_getViewer_leavesUserAgent(t *testing.T) {
 	var receivedUA string
 	var receivedAuth string
 
-	// Outer transport sets User-Agent, simulating the factory-built client's header middleware.
-	// Inner transport captures headers as-received to verify they survived the wrapping.
 	plainClient := &http.Client{
 		Transport: &roundTripper{roundTrip: func(req *http.Request) (*http.Response, error) {
-			req.Header.Set("User-Agent", "GitHub CLI 1.2.3 Agent/copilot-cli")
-			return (&http.Client{
-				Transport: &roundTripper{roundTrip: func(req *http.Request) (*http.Response, error) {
-					receivedUA = req.Header.Get("User-Agent")
-					receivedAuth = req.Header.Get("Authorization")
-					return &http.Response{
-						StatusCode: 200,
-						Header:     http.Header{"Content-Type": []string{"application/json"}},
-						Body:       io.NopCloser(bytes.NewBufferString(`{"data":{"viewer":{"login":"monalisa"}}}`)),
-						Request:    req,
-					}, nil
-				}},
-			}).Transport.RoundTrip(req)
+			receivedUA = req.Header.Get("User-Agent")
+			receivedAuth = req.Header.Get("Authorization")
+
+			return &http.Response{
+				StatusCode: 200,
+				Header:     http.Header{"Content-Type": []string{"application/json"}},
+				Body:       io.NopCloser(bytes.NewBufferString(`{"data":{"viewer":{"login":"monalisa"}}}`)),
+				Request:    req,
+			}, nil
 		}},
 	}
 
 	login, err := getViewer(plainClient, "github.com", "test-token")
 	require.NoError(t, err)
 	assert.Equal(t, "monalisa", login)
-	assert.Equal(t, "GitHub CLI 1.2.3 Agent/copilot-cli", receivedUA)
+	assert.Empty(t, receivedUA, "User-Agent header should be left unset so that downstream transports can set it")
 	assert.Equal(t, "token test-token", receivedAuth)
 }