tests/testthat/test-fit.R

In tidymodels/workflows: Workflows

test_that("can `fit()` a workflow with a recipe", {
  rec <- recipes::recipe(mpg ~ cyl, mtcars)

  mod <- parsnip::linear_reg()
  mod <- parsnip::set_engine(mod, "lm")

  workflow <- workflow()
  workflow <- add_recipe(workflow, rec)
  workflow <- add_model(workflow, mod)

  result <- fit(workflow, mtcars)

  expect_is(result$fit$fit, "model_fit")

  expect_equal(
    coef(result$fit$fit$fit),
    coef(lm(formula = mpg ~ cyl, data = mtcars))
  )
})

test_that("can `fit()` a workflow with a formula", {
  mod <- parsnip::linear_reg()
  mod <- parsnip::set_engine(mod, "lm")

  workflow <- workflow()
  workflow <- add_formula(workflow, mpg ~ cyl)
  workflow <- add_model(workflow, mod)

  result <- fit(workflow, mtcars)

  expect_is(result$fit$fit, "model_fit")

  expect_equal(
    coef(result$fit$fit$fit),
    coef(lm(formula = mpg ~ cyl, data = mtcars))
  )
})

test_that("missing `data` argument has a nice error", {
  mod <- parsnip::linear_reg()
  mod <- parsnip::set_engine(mod, "lm")

  workflow <- workflow()
  workflow <- add_formula(workflow, mpg ~ cyl)
  workflow <- add_model(workflow, mod)

  expect_error(fit(workflow), "`data` must be provided to fit a workflow")
})

test_that("cannot fit without a pre stage", {
  mod <- parsnip::linear_reg()
  mod <- parsnip::set_engine(mod, "lm")

  workflow <- workflow()
  workflow <- add_model(workflow, mod)

  expect_error(fit(workflow, mtcars), "must have a formula or recipe")
})

test_that("cannot fit without a fit stage", {
  workflow <- workflow()
  workflow <- add_formula(workflow, mpg ~ cyl)

  expect_error(fit(workflow, mtcars), "must have a model")
})