Templated messages

[ramnathv]

@filipsch A lot of times I see custom messages that simply use a different template from the default and hence are NOT completely custom. Here is an example:

ex() %>%
  check_function('str_detect') %>%
  check_argument(
      'string',
      "Did you remember to specify the `string` argument in this call to `str_detect()`?") 
  ) %>%
  check_equal(
      incorrect_msg = "The `string` argument in your `str_detect()` call is incorrect.",
      append = FALSE 
  )

I see two ways we can make writing such messages a lot easier:

1 | Allow instructors to specify a template to these functions instead of a string. For example a glue template could be

Did you remember to specify the {arg} argument in this call to {fun}()?"

2 | We can predefine a set of templates in testwhat and randomly select one while reporting. This will possibly reduce SCT fatigue by adding variation to the messages at little cost. I am a big fan of this approach.

cc @martijnsublime @ncarchedi

[filipsch]

@ramnathv This is what you can already do in pythonwhat (although it's not actively documented), and it could make sense to do it in testwhat as well. Worth considering.

[ramnathv]

@filipsch Mm did not know about the hidden easter egg in pythonwhat :) I have not analyzed the data on custom messages yet, but it seems like most of the time they are just variants of a template.