Boolean literal mutators

Returns a ready-made list of boolean_literal() mutators covering all canonical flips: TRUE/FALSE and T/F.

Usage

boolean_literals()

Value

A list of boolean_literal() mutators.

Details

Use on any file that passes or returns boolean flags. A surviving mutant from this preset typically means a test checks a side effect of the flag (e.g. the branch taken) rather than the flag value itself — adding expect_true()/expect_false() on the return value 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

boolean_literals()
#> [[1]]
#> Mutator: TRUE → FALSE
#> Query: (true) @value
#> 
#> [[2]]
#> Mutator: FALSE → TRUE
#> Query: (false) @value
#> 
#> [[3]]
#> Mutator: T → F
#> Query: (identifier) @value (#eq? @value "T")
#> 
#> [[4]]
#> Mutator: F → T
#> Query: (identifier) @value (#eq? @value "F")
#> 

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