fix race in windows test

Author: evict

internal/batches/service/remote_windows_test.go

@@ -44,10 +44,15 @@ func TestService_UploadBatchSpecWorkspaceFiles_Windows_Path(t *testing.T) {
 	svc := service.New(&service.Opts{Client: client})
 
 	// Body will get set with the body argument to NewHTTPRequest
+	// We must consume the pipe reader synchronously to avoid a data race between
+	// the goroutine writing to the pipe and testify/mock inspecting arguments via reflection.
+	var bodyContent bytes.Buffer
 	req := httptest.NewRequest(http.MethodPost, "http://fake.com/.api/files/batch-changes/123", nil)
 	client.On("NewHTTPRequest", mock.Anything, http.MethodPost, ".api/files/batch-changes/123", mock.Anything).
 		Run(func(args mock.Arguments) {
-			req.Body = args[3].(*io.PipeReader)
+			pipeReader := args[3].(*io.PipeReader)
+			io.Copy(&bodyContent, pipeReader)
+			req.Body = io.NopCloser(&bodyContent)
 		}).
 		Return(req, nil).
 		Once()