Inform the user about how gradethis interprets piped code

Creates a warning message when user code contains the %>%. When feedback is automatically generated via code_feedback() or in grade_this_code(), this message attempts to contextualize feedback that might make more sense when referenced against an un-piped version of the student's code.

Usage

pipe_warning(message = getOption("gradethis.pipe_warning"), .user_code = NULL)

Arguments

message: A glue string containing the message. The default value is set with the gradethis.pipe_warning option.
.user_code: The user's submitted code, found in env if NULL

Value

Returns a string containing the pipe warning message, or an empty string if the .user_code does not contain a pipe, if the .user_code is also empty, or if the message is NULL.

Options

gradethis.pipe_warning: The default pipe warning message is set via this option.

Glue Variables

The following variables may be used in the glue-able message:

.user_code: The student's original submitted code.
.user_code_unpiped: The unpiped version of the student's submitted code.

Examples

# The default `pipe_warning()` message:
getOption("gradethis.pipe_warning")
#> [1] "I see that you are using pipe operators (e.g. %>%), so I want to let you know that this is how I am interpreting your code before I check it:\n\n```r\n{.user_code_unpiped}\n```\n\n"

# Let's consider two versions of the user code
user_code <-  "penguins %>% pull(year) %>% min(year)"
user_code_unpiped <- "min(pull(penguins, year), year)"

# A `pipe_warning()` is created when the user's code contains `%>%`
pipe_warning(.user_code = user_code)
#> I see that you are using pipe operators (e.g. %>%), so I want to let you know that this is how I am interpreting your code before I check it:
#> 
#> ```r
#> min(pull(penguins, year), year)
#> ```
#> 
#> 

# And no message is created when the user's code in un-piped
pipe_warning(.user_code = user_code_unpiped)
#> [1] ""

# Typically, this warning is only introduced when giving code feedback
# for an incorrect submission. Here we didn't expect `year` in `min()`.
submission <- mock_this_exercise(
  .user_code = !!user_code,
  .solution_code = "penguins %>% pull(year) %>% min()"
)

grade_this_code()(submission)
#> <gradethis_graded_this_code: [Incorrect]
#>   I see that you are using pipe operators (e.g. %>%), so I want
#>   to let you know that this is how I am interpreting your code
#>   before I check it:
#> 
#>   ```r
#>   min(pull(penguins, year), year)
#>   ```
#> 
#>   I did not expect your call to `min()` to include `year`. You
#>   may have included an unnecessary argument, or you may have left
#>   out or misspelled an important argument name. But no need to
#>   fret, try it again.
#> >