The function makeAssertCollection() returns a simple stack-like
closure you can pass to all functions of the assert*-family.
All messages get collected and can be reported with reportAssertions().
Alternatively, you can easily write your own report function or customize the the output of
the report function to a certain degree.
See the example on how to push custom messages or retrieve all stored messages.
makeAssertCollection()
reportAssertions(collection)[AssertCollection]
Object of type “AssertCollection” (constructed via makeAssertCollection).
makeAssertCollection() returns an object of class “AssertCollection” and
reportCollection returns invisibly TRUE if no error is thrown (i.e., no message was
collected).
x = "a"
coll = makeAssertCollection()
print(coll$isEmpty())
#> [1] TRUE
assertNumeric(x, add = coll)
coll$isEmpty()
#> [1] FALSE
coll$push("Custom error message")
coll$getMessages()
#> [1] "Variable 'x': Must be of type 'numeric', not 'character'."
#> [2] "Custom error message"
if (FALSE) {
reportAssertions(coll)
}