with_mock_path function

Run the DBI queries in an alternate mock directory

When testing with dittodb, wrap your tests in with_mock_path({}) to use the database fixtures located in other directories. dittodb will look for fixtures in the directory specified by the user, which can be a temporary or permanent location.

with_mock_path(path, expr, replace = FALSE)

Arguments

• path: the alternate directory
• expr: the expression to execute
• replace: logical, should the path replace the current mock paths (TRUE) or should they be appended (to the beginning) of the current mock paths (default, FALSE)

Returns

nothing, called to execute the expression(s) in expr

Examples

# Only run if RSQLite and testthat are available
if (check_for_pkg("RSQLite", message) & check_for_pkg("testthat", message)) {
  with_mock_path(
    system.file("nycflight_mocks", package = "dittodb"),
    with_mock_db({
      con <- DBI::dbConnect(
        RSQLite::SQLite(),
        dbname = "nycflights"
      )

      one_airline <- dbGetQuery(
        con,
        "SELECT carrier, name FROM airlines LIMIT 1"
      )
      testthat::test_that("We get one airline", {
        testthat::expect_s3_class(one_airline, "data.frame")
        testthat::expect_equal(nrow(one_airline), 1)
        testthat::expect_equal(one_airline$carrier, "9E")
        testthat::expect_equal(one_airline$name, "Endeavor Air Inc.")
      })
      one_airline
    })
  )
}