tests/testthat/test-expressions.R

In rbiogeme: Interface to 'Biogeme'

test_that("parameters and variables create expression objects", {
  parameter <- biogeme_beta("b_time", start = -1, lower = -10, upper = 0)
  time <- variable("TIME")

  expect_s3_class(parameter, "biogeme_beta")
  expect_s3_class(time, "biogeme_variable")
  expect_equal(parameter$name, "b_time")
  expect_equal(time$name, "TIME")
})

test_that("arithmetic creates a neutral expression tree", {
  expression <- biogeme_beta("b_time") * variable("TIME") + 3

  expect_s3_class(expression, "biogeme_expression")
  expect_equal(expression$kind, "binary")
  expect_equal(expression$operator, "+")
  expect_equal(format(expression), "((b_time * TIME) + 3)")
})

test_that("unary functions and numeric-left operators work", {
  expression <- 2 + exp(-biogeme_beta("x") / variable("income"))

  expect_s3_class(expression, "biogeme_expression")
  expect_equal(
    format(expression),
    "(2 + exp(((-x) / income)))"
  )
})

test_that("parameter validation catches malformed definitions", {
  expect_error(biogeme_beta("", start = 0), "name")
  expect_error(biogeme_beta("x", start = NA_real_), "finite")
  expect_error(biogeme_beta("x", start = 2, upper = 1), "upper")
  expect_error(biogeme_beta("x", lower = 2, upper = 1), "lower")
  expect_error(variable(NA_character_), "name")
})