NA and NULL literal mutators

Returns a ready-made list of na_literal() mutators covering common swaps between NA, NULL, and the typed NA variants (NA_real_, NA_integer_, NA_character_).

Usage

na_literals()

Value

A list of na_literal() mutators.

Details

Use on any file that handles missing values or nullable results. A surviving mutant typically means tests never distinguish NA from NULL, or never check which typed NA is returned — adding expect_true(is.na(x)) and expect_equal(class(x), "numeric") style assertions kills it.

See also

vignette("mutators", package = "muttest") for the full mutator table.

vignette("interpreting-results", package = "muttest") for how to diagnose survivors and fix the underlying test weakness.

Examples

na_literals()
#> [[1]]
#> Mutator: NA → NULL
#> Query: (na) @value
#> 
#> [[2]]
#> Mutator: NULL → NA
#> Query: (null) @value
#> 
#> [[3]]
#> Mutator: NA → NA_real_
#> Query: (na) @value
#> 
#> [[4]]
#> Mutator: NA_real_ → NA
#> Query: (na) @value
#> 
#> [[5]]
#> Mutator: NA → NA_integer_
#> Query: (na) @value
#> 
#> [[6]]
#> Mutator: NA_integer_ → NA
#> Query: (na) @value
#> 
#> [[7]]
#> Mutator: NA → NA_character_
#> Query: (na) @value
#> 
#> [[8]]
#> Mutator: NA_character_ → NA
#> Query: (na) @value
#> 

if (FALSE) { # \dontrun{
plan <- muttest_plan(
  source_files = "R/missing.R",
  mutators = na_literals()
)
muttest(plan, "tests/testthat")
} # }