Different output when using col_names and col_types w/ ignored col between dev and CRAN versions

[niheaven]

After updating to readr dev version, some behaviors change if I read a file without colnames and I want to specify some while ignoring other cols.

• With CRAN 1.4.0

sessioninfo::package_info("readr", dependencies = FALSE)
#>  package * version date       lib source        
#>  readr     1.4.0   2020-10-05 [1] CRAN (R 4.1.0)
#> 
#> [1] E:/Documents/R/win-library/4.1
#> [2] D:/Scoop/apps/r/4.1.0/library
x <- tibble::tribble(~x, ~y, ~z,
                     1, 2, 3,
                     4, 5, 6,
                     7, 8, 9)
readr::write_csv(x, "test.csv", col_names = FALSE)
readr::read_csv("test.csv",
                col_names = c("a", "b"),
                col_types = "-ii")
#> # A tibble: 3 x 2
#>       a     b
#>   <int> <int>
#> 1     2     3
#> 2     5     6
#> 3     8     9

• With dev

sessioninfo::package_info("readr", dependencies = FALSE)
#>  package * version    date       lib source                          
#>  readr     1.9.9.9000 2021-06-02 [1] Github (tidyverse/readr@df90fb9)
#> 
#> [1] E:/Documents/R/win-library/4.1
#> [2] D:/Scoop/apps/r/4.1.0/library
x <- tibble::tribble(~x, ~y, ~z,
                     1, 2, 3,
                     4, 5, 6,
                     7, 8, 9)
readr::write_csv(x, "test.csv", col_names = FALSE)
readr::read_csv("test.csv",
                col_names = c("a", "b"),
                col_types = "-ii")
#> # A tibble: 3 x 2
#>       b    X3
#>   <int> <int>
#> 1     2     3
#> 2     5     6
#> 3     8     9
readr::read_csv("test.csv",
                col_names = c("unused", "a", "b"),
                col_types = "-ii")
#> # A tibble: 3 x 2
#>       a     b
#>   <int> <int>
#> 1     2     3
#> 2     5     6
#> 3     8     9

As you can see, the recent version read correct column, but assigned incorrect names. If there is a little column, it's worth. But if there are lots of columns that only few of them is needed and I only want to assign names to these needed ones, 1.4.0's params are preferred.

I try to use new col_select param, but cannot find a way that behaves just like the former one.

[jimhester]

tidyverse/vroom#293 is tracking this issue, unfortunately it isn't entirely trivial to fix.

[niheaven]

Thanks, so now I'll mark my code with this notable change 😭