Expectations: exclusivity

expect_exclusive tests that vars are exclusive - that, if any one of vars is set to exc_val, no other column in vars or var_set is also set to exc_val.

expect_exclusive(vars, var_set, exc_val = 1, flt = TRUE, data = get_testdata())

Arguments

vars

<tidy-select> A set of columns to test.

var_set

<tidy-select> The full set of columns to check against. This should include all columns specified in the vars argument.

exc_val

The value that flags a variable as "selected" (default: 1)

flt

<data-masking> A filter specifying a subset of the data frame to test.

data

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

Details

This expectation is designed to check exclusivity in survey multiple response sets, where one response is only valid on its own.

See the example data set below:

• No record should have q10_98, "None of the above", selected while also having any other response selected, so we refer to this as an "exclusive" response.

• expect_exclusive() checks whether q10_98 "None of the above" or q10_99 "Don't know", the exclusive responses, have been selected alongside any other q10_* response.

• The expectation fails, since the first record has both q10_1 and q10_98 selected.

See also

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

Examples

my_q_block <- data.frame(
  resp_id = 1:5, # Unique to respondent
  q10_1  = c(1, 1, 0, 0, 0),
  q10_2  = c(0, 1, 0, 0, 0),
  q10_3  = c(0, 0, 1, 0, 0),
  q10_98 = c(1, 0, 0, 1, 0), # None of the above
  q10_99 = c(0, 0, 0, 0, 1)  # Item not answered
)

# Make sure that if "None of the above" and "Item skipped" are selected
# none of the other question options are selected:
try(
expect_exclusive(
  c(q10_98, q10_99),
  starts_with("q10_"),
  data = my_q_block
)
)
#> Error : `my_q_block` has 1 records with non-exclusive values in variables `q10_98, q10_99` in variable set `starts_with("q10_")`.
#> Filter: None