Fix up date columns in R

fix_dates.R

df_messy_dates <- tribble(
  ~col1_dt, ~col2_dt, ~other_data,
  "2019-01-01", "2019-01-02", "a",
  "2019-01-03", "1/4/2019", "b",
  "01/05/2019", "2019-01-06", "c"
)

# A tibble: 3 x 3
#   col1_dt    col2_dt    other_data
#   <chr>      <chr>      <chr>     
# 1 2019-01-01 2019-01-02 a         
# 2 2019-01-03 1/4/2019   b         
# 3 01/05/2019 2019-01-06 c   

fn_date_fixer <- function(col) { 
  output <- c() 
  for(cell in col) { 
    if(is.na(cell) || cell == "") {
      # "" will cause `lubridate` to fail, so replace with NA
      output <- c(output, NA) 
    }
    else if(typeof(cell) == "character") { 
      parsed <- readr::parse_date(cell, format="%Y-%m-%d") 
      if(is.na(parsed)) { 
        parsed <- readr::parse_date(cell, format="%m/%d/%Y") 
      } 
      if(is.na(parsed)) { 
        stop(str_interp("Could not parse ${cell}")) 
      } 
      output <- c(output, parsed) 
    } 
    else { 
      output <- c(output, cell) 
    } 
  } 
  return(lubridate::as_date(output)) 
} 

df_clean_dates <- df_messy_dates %>% 
  mutate_at(
    vars(ends_with("_dt")),
    list( 
      ~ fn_date_fixer(.)
    )
  )

df_clean_dates

# A tibble: 3 x 3
#   col1_dt    col2_dt    other_data
#   <date>     <date>     <chr>     
# 1 2019-01-01 2019-01-02 a         
# 2 2019-01-03 2019-04-01 b         
# 3 2019-05-01 2019-01-06 c