Fix TestGettingTrackingData flakiness (open-telemetry#27927)

**Description:**
Fix flakiness in the
`TestGettingTrackingData/Timeout_waiting_for_response` test. The root
cause of the issue is that the `client` and `server` are connected to
same pipe and if the server attempts to read after the client is closed
it reports error EOF and the test code expects no error from the read
operation. The issue is not specific to Windows. The fix was to give
control to each test case of the read and write functions so this type
of synchronization issue can be properly handled while keeping the test
code coverage.

**Link to tracking Issue:**
Fix open-telemetry#25188

**Testing:**
Multiple local runs with various cpu settings.

**Documentation:** N/A

Co-authored-by: Alex Boten <[email protected]>

receiver/chronyreceiver/internal/chrony/client_test.go

@@ -17,7 +17,7 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
-func newMockConn(tb testing.TB, handler func(net.Conn) error) net.Conn {
+func newMockConn(tb testing.TB, serverReaderFn, serverWriterFn func(net.Conn) error) net.Conn {
 	client, server := net.Pipe()
 
 	var wg sync.WaitGroup
@@ -32,8 +32,19 @@ func newMockConn(tb testing.TB, handler func(net.Conn) error) net.Conn {
 	go func() {
 		defer wg.Done()
 
-		assert.NoError(tb, binary.Read(server, binary.BigEndian, &requestTrackingContent{}), "Must not error when reading binary data")
-		assert.NoError(tb, handler(server), "Must not error when processing request")
+		if serverReaderFn == nil {
+			serverReaderFn = func(conn net.Conn) error {
+				return binary.Read(conn, binary.BigEndian, &requestTrackingContent{})
+			}
+		}
+		assert.NoError(tb, serverReaderFn(server), "Must not error when reading binary data")
+
+		if serverWriterFn == nil {
+			serverWriterFn = func(conn net.Conn) error {
+				return nil
+			}
+		}
+		assert.NoError(tb, serverWriterFn(server), "Must not error when processing request")
 	}()
 	return client
 }
@@ -74,17 +85,18 @@ func TestGettingTrackingData(t *testing.T) {
 	t.Parallel()
 
 	tests := []struct {
-		scenario string
-		handler  func(conn net.Conn) error
-		dialTime time.Duration
-		timeout  time.Duration
-		data     *Tracking
-		err      error
+		scenario       string
+		serverReaderFn func(conn net.Conn) error
+		serverWriterFn func(conn net.Conn) error
+		dialTime       time.Duration
+		timeout        time.Duration
+		data           *Tracking
+		err            error
 	}{
 		{
 			scenario: "Successful read binary from socket",
 			timeout:  10 * time.Second,
-			handler: func(conn net.Conn) error {
+			serverWriterFn: func(conn net.Conn) error {
 				type response struct {
 					ReplyHead
 					replyTrackingContent
@@ -142,15 +154,15 @@ func TestGettingTrackingData(t *testing.T) {
 			scenario: "Timeout waiting for dial",
 			timeout:  10 * time.Millisecond,
 			dialTime: 100 * time.Millisecond,
-			handler: func(conn net.Conn) error {
+			serverReaderFn: func(conn net.Conn) error {
 				return nil
 			},
 			err: os.ErrDeadlineExceeded,
 		},
 		{
 			scenario: "Timeout waiting for response",
 			timeout:  10 * time.Millisecond,
-			handler: func(conn net.Conn) error {
+			serverReaderFn: func(conn net.Conn) error {
 				time.Sleep(100 * time.Millisecond)
 				return nil
 			},
@@ -160,7 +172,7 @@ func TestGettingTrackingData(t *testing.T) {
 			scenario: "Timeout waiting for response because of slow dial",
 			timeout:  100 * time.Millisecond,
 			dialTime: 90 * time.Millisecond,
-			handler: func(conn net.Conn) error {
+			serverWriterFn: func(conn net.Conn) error {
 				time.Sleep(20 * time.Millisecond)
 				return nil
 			},
@@ -169,7 +181,7 @@ func TestGettingTrackingData(t *testing.T) {
 		{
 			scenario: "invalid status returned",
 			timeout:  5 * time.Second,
-			handler: func(conn net.Conn) error {
+			serverWriterFn: func(conn net.Conn) error {
 				resp := &ReplyHead{
 					Version: 6,
 					Status:  1,
@@ -182,7 +194,7 @@ func TestGettingTrackingData(t *testing.T) {
 		{
 			scenario: "invalid status command",
 			timeout:  5 * time.Second,
-			handler: func(conn net.Conn) error {
+			serverWriterFn: func(conn net.Conn) error {
 				resp := &ReplyHead{
 					Version: 6,
 					Status:  successfulRequest,
@@ -205,7 +217,7 @@ func TestGettingTrackingData(t *testing.T) {
 						return nil, os.ErrDeadlineExceeded
 					}
 
-					return newMockConn(t, tc.handler), nil
+					return newMockConn(t, tc.serverReaderFn, tc.serverWriterFn), nil
 				}
 			})
 			require.NoError(t, err, "Must not error when creating client")