r - 使用匹配时 dplyr 与 testthat 包发生冲突

Question

我收到错误，因为 testthat::matches 与 dplyr::matches 冲突，我想知道如何使用 testthat::test_file 检查包含对 matches() 调用的函数，而无需在函数体中指定 dplyr::matches。

例如:

> testthat::test_file('tmp_fn_testthat_test.R')

Attaching package: ‘testthat’

The following object is masked from ‘package:dplyr’:

    matches

The following object is masked from ‘package:purrr’:

    is_null

 Show Traceback

 Rerun with Debug
 Error in -matches("tmp") : invalid argument to unary operator In addition: Warning message:
package ‘testthat’ was built under R version 3.2.5 

DONE =========================================================================================================================================

可以通过将以下代码保存在工作目录中名为 tmp_fn_testthat_test.R 的文件中并运行命令 testthat::test_file('tmp_fn_testthat_test_20161115.R') 来重现此错误。请注意，在未加载 testthat 时获取或运行 expect_equal 命令会使测试通过。

tmp_fn <- function() {
    tmp_df <- data.frame(tmp_a = 1, tmp_b = 2)

    tmp_df %>%
        select(-matches('tmp')) %>%
        ncol


}

testthat::expect_equal(tmp_fn(), 0)

Answer 1

This is a known issue dplyr 0.5。推荐的解决方案是使用显式命名空间前缀:dplyr::matches。