inst/tinytest/test_dropj_grep.R

In DavidJesse21/data.table.utils: Extra Functions for the data.table Package

dt_check = data.table::as.data.table(iris)

# Test sanity checks ----

# `DT` needs to be a data.table
df_test = iris
expect_error(dropj_grep(df_test, "^Sepal"))
expect_error(
  dropj_grep(list(a = 1, b = 2,), "a")
)

# `pattern` must be a string (i.e. character vector of length one)
expect_error(dropj_grep(dt_check, c("^Sepal", "^Petal")))
expect_error(dropj_grep(dt_check, 3L))


# Test normal functionality ----

dt1 = data.table::copy(dt_check)
dropj_grep(dt1, "^Sepal")
expect_false(any(
  c("Sepal.Length", "Sepal.Width") %in% colnames(dt1)
))
expect_true(all(
  c("Petal.Length", "Petal.Width", "Species") %in% colnames(dt1)
))

# Case: no pattern matching
dt2 = data.table::copy(dt_check)
expect_message(dropj_grep(dt2, "^sepal_"))

# Invisible return and chaining works
dt3 = data.table::copy(dt_check)
expect_true(
  inherits(dropj_grep(dt3, "^Sepal"), "data.table")
)

dt4 = data.table::copy(dt_check)
dt4 = dropj_grep(dt4, "^Sepal")[1:10]
expect_true(inherits(dt4, "data.table"))
expect_equal(nrow(dt4), 10)


rm(dt_check, df_test, dt1, dt2, dt3, dt4)