How to test R package without returning error messages?

applying test() command on my R package returned error message: "No tests: no files in C:\Users\Administrator\Desktop\summarize.4.MSdata/tests/testthat match '^test.*.[rR]$'". then, when I moved "testthat.R" file to "testthat" directory, it returned another error message "Error: No tests found for summarize.4.MSdata Execution halted Exited with status 1."

thank you in advance.