insist_rows: Raises error if dynamically created predicate is FALSE for...
In lorenzwalthert/assertr: Assertive Programming for R Analysis Pipelines

Description Usage Arguments Details Value Note See Also Examples

Meant for use in a data analysis pipeline, this function applies a function to a data frame that reduces each row to a single value. Then, a predicate generating function is applied to row reduction values. It will then use these predicates to check each of the row reduction values. If any of these predicate applications yield FALSE, this function will raise an error, effectively terminating the pipeline early. If there are no FALSEs, this function will just return the data that it was supplied for further use in later parts of the pipeline.

insist_rows(data, row_reduction_fn, predicate_generator, ...,
  success_fun = success_continue, error_fun = error_stop)

insist_rows_(data, row_reduction_fn, predicate_generator, ..., .dots,
  success_fun = success_continue, error_fun = error_stop)

`data`	A data frame
`row_reduction_fn`	A function that returns a value for each row of the provided data frame
`predicate_generator`	A function that is applied to the results of the row reduction function. This will produce, a true predicate function to be applied to every element in the vector that the row reduction function returns.
`...`	Comma separated list of unquoted expressions. Uses dplyr's `select` to select columns from data.
`success_fun`	Function to call if assertion passes. Defaults to returning `data`.
`error_fun`	Function to call if assertion fails. Defaults to printing a summary of all errors.
`.dots`	Use insist_rows_() to select columns using standard evaluation.

For examples of possible choices for the success_fun and error_fun parameters, run help("success_and_error_functions")

By default, the data is returned if dynamically created predicate assertion is TRUE and and error is thrown if not. If a non-default success_fun or error_fun is used, the return values of these function will be returned.

See vignette("assertr") for how to use this in context

insist assert_rows assert verify

# returns mtcars
insist_rows(mtcars, maha_dist, within_n_mads(30), mpg:carb)

# equivalent using standard evaluation
insist_rows_(mtcars, maha_dist, within_n_mads(30), "mpg:carb")


library(magrittr)                    # for piping operator

mtcars %>%
  insist_rows(maha_dist, within_n_mads(10), vs:am)
  # anything here will run

## Not run: 
mtcars %>%
  insist_rows(maha_dist, within_n_mads(1), everything())
  # the assertion is untrue so
  # nothing here will run
## End(Not run)