Logical operator mutators

Returns a ready-made list of operator() mutators covering short-circuit (&&/||) and vectorised (&/|) logical operator swaps.

Usage

logical_operators()

Value

A list of operator() mutators.

Details

Use on any file with compound conditions (if (a && b)). A surviving mutant from this preset typically means test inputs are symmetric — both flags TRUE or both FALSE. Adding a test with one flag TRUE and the other FALSE exposes the difference between && and || and kills the mutant.

See also

vignette("mutators", package = "muttest") for the full operator table and a worked example showing the symmetric-input pattern.

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

Examples

logical_operators()
#> [[1]]
#> Mutator: && → ||
#> Query: (binary_operator
#>       lhs: (_) @lhs
#>       operator: _ @operator
#>       rhs: (_) @rhs
#>       (#eq? @operator "&&")
#>     )
#> 
#> [[2]]
#> Mutator: || → &&
#> Query: (binary_operator
#>       lhs: (_) @lhs
#>       operator: _ @operator
#>       rhs: (_) @rhs
#>       (#eq? @operator "||")
#>     )
#> 
#> [[3]]
#> Mutator: & → |
#> Query: (binary_operator
#>       lhs: (_) @lhs
#>       operator: _ @operator
#>       rhs: (_) @rhs
#>       (#eq? @operator "&")
#>     )
#> 
#> [[4]]
#> Mutator: | → &
#> Query: (binary_operator
#>       lhs: (_) @lhs
#>       operator: _ @operator
#>       rhs: (_) @rhs
#>       (#eq? @operator "|")
#>     )
#> 

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