Handle database tables?

[gadenbuie]

Maybe tblcheck should include some special handling for remote database tables. Here's a smaller example based on the Introduction to dbplyr • dbplyr:

library(dplyr)
con <- DBI::dbConnect(RSQLite::SQLite(), dbname = ":memory:")

copy_to(con, nycflights13::flights[1:100, ], "flights",
        temporary = FALSE, 
        indexes = list(
          c("year", "month", "day"), 
          "carrier", 
          "tailnum",
          "dest"
        )
)

Given a remote database table, flights_db, tbl_grade() errors because the expected object is not a data.frame.

flights_db <- tbl(con, "flights")

tblcheck::tbl_grade(flights_db, flights_db)
#> An error occurred in the grading code: Assertion on 'expected' failed: Must be of type 'data.frame', not 'tbl_SQLiteConnection/tbl_dbi/tbl_sql/tbl_lazy/tbl'.
#> <gradethis_graded: [Neutral]
#>   Uh-oh! We can't provide feedback at this time. Don't worry, it's not
#>   your fault! There's an issue behind-the-scenes with this exercise.
#> >

For now authors can collect(.result) and collect(.solution), but maybe tbl_grade() could handle this automatically. Alternatively, we could think about rendering the lazy tbl to SQL or doing something else to avoid having to collect the complete data...

flights <- collect(flights_db)
tblcheck::tbl_grade(flights, flights)