Expectations: consistency

These functions test whether multiple conditions coexist.

expect_cond(cond1, cond2, data = get_testdata())

expect_base(
  var,
  base,
  miss = getOption("testdat.miss"),
  missing_valid = FALSE,
  data = get_testdata()
)

Arguments

cond1

<data-masking> First condition (antecedent) for consistency check.

cond2

<data-masking> Second condition (consequent) for consistency check.

data

A data frame to test. The global test data is used by default.

var

An unquoted column name to test.

base

<data-masking> The condition that determines which records should be non-missing.

miss

A vector of values to be treated as missing. The testdat.miss option is used by default.

missing_valid

Should missing values be treated as valid for records meeting the base condition? This allows 'one way' base checks. This is FALSE by default.

Value

expect_*() functions are mainly called for their side effects. The expectation signals its result (e.g. "success", "failure"), which is logged by the current test reporter. In a non-testing context the expectation will raise an error with class expectation_failure if it fails.

Functions

• expect_cond(): Checks the coexistence of two conditions. It can be read as "if cond1 then cond2".

• expect_base(): A special case that checks missing data against a specified condition. It can be read as "if base then var not missing, if not base then var missing".

See also

Other data expectations: datacomp-expectations, date-expectations, exclusivity-expectations, expect_depends(), generic-expectations, label-expectations, pattern-expectations, proportion-expectations, text-expectations, uniqueness-expectations, value-expectations

Examples

my_survey <- data.frame(
  resp_id = 1:5,
  q1a = c(0, 1, 0, 1, 0),
  q1b = c(NA, NA, NA, 1, 0), # Asked if q1a %in% 1
  q2a = c(90, 80, 60, 40, 90),
  q2b = c("", "", NA, "Some reason for low rating", "") # Asked if q2a < 50
)

# Check that q1b has a value if and only if q1a %in% 1
try(expect_base(q1b, q1a %in% 1, data = my_survey)) # Fails for resp_id 2 and 5
#> Error : `my_survey` has a base mismatch in variable `q1b`.
#> 1 cases have `q1a %in% 1` but `q1b` is missing.
#> 1 cases do not have `q1a %in% 1` but `q1b` is non missing.

# Check that q2b has a value if and only if q2a < 50
expect_base(q2b, q2a < 50, data = my_survey)

# Check that if q1a %in% 0 then q2a > 50 (but not vice-versa)
expect_cond(q1a %in% 0, q2a > 50, data = my_survey)