Use cli package for warnings and messages, drop assertthat

[peterdesmet]

Rather than constructing glue messages, use the cli package to format messages/formats: https://cli.r-lib.org/ While doing so:

• Drop use of assertthat
• Use error classes rather than always testing on the returned error message

add_resource()

• assert: valid resource name
• assert: already has that resource name
• assert: data must be dataframe or path
• assert: all arguments must be named
• assert: conflicting properties

check_package(): #165

• assert: has resources and directory
• assert: resources is list, directory is char
• assert: all resources have a name

check_path(): #164

• assert: absolute path
• assert: relative parent path
• assert: file exists at url
• assert: file exists at path

check_schema():

• assert: schema must be a list with property fields
• assert: All fields in schema must have property name.
• assert: All fields in schema must have valid type.
• assert: data must be a data frame containing data.
• assert: Field names in schema must match column names in data

create_schema()

• assert: data must be a data frame containing data.

get_resource()

• assert: is known resource name
• assert: resource has path or data

get_schema()

• assert: is tabular resource
• assert: has schema

read_package()

• assert: file is character
• assert: descriptor has resources
• message: give credit

read_resource()

• assert: can't find column
• assert: fields must have name

write_package()

• assert: package must have resources

write_resource()

• message: downloading file

overall

• Remove assertthat dependency
• Remove glue dependency
• All conditions use || or &&
• Make use of the words valid and invalid rather than correct and incorrect in tests
• Update NEWS.md
• Create new version

[peterdesmet]

As part of this, I wondered how to combine cli_abort() with assert_that(). Both already return a message, so wrapping cli_abort() in assert_that() (while it works), feels wrong:

library(assertthat)
library(cli)
x <- FALSE
assert_that(
  is.character(x),
  msg = cli::cli_abort("{.arg x} must be a character.") # A message call within a message call
)

Then I noticed that asserthat is actually not used in many Tidyverse packages (vroom, dplyr):

• stopifnot() seems to be used when no message is returned
• if() is used for other checks

That latter approach seems a bit harder to Cmd+F for assertions, but the code probably already contains other assertions that are not using assertthat anyway. So maybe we should drop it as a dependency and write assertions with cli_abort() cf. vroom:

if (!is.character(x)) {
  cli::cli_abort("{.arg x} must be a character.")
}

[peterdesmet]

Note also that vectors no longer need to be collapsed beforehand