In choogland/christinehoogland.pkg: Certification Level 2 - Developer - Exam

library(testthat)
library(assertthat)
library(dplyr)

Function bmi

This function returns the Body Mass Index of an individual (https://en.wikipedia.org/wiki/Body_mass_index).

The function must take 2 parameters, the mass in kg and the height in meter. It returns the result of the operation mass/(height * height).

#' bmi Body Mass Index of an individual
#'
#' @param mass in kg
#' @param height in m
#' @return bmi as mass/(height * height)
#' @importFrom assertthat assert_that
#' @importFrom dplyr mutate
#' @export
#'
#' @examples
bmi <- function(mass, height) {
  if(!(is.na(mass)|(is.numeric(mass)&mass>0))) {stop("mass should be numeric and >0")}
  if(!(is.na(height)|(is.numeric(height)&height>0))) {stop("height should be numeric and >0")}
  bmi <- NA
  if (!is.na(mass)&!is.na(height)) {
    bmi <- mass/(height * height)
  }
  return(bmi)
}

bmi(mass = 80, height = 1.80)
bmi(mass = NA, height = 1.80)
bmi(mass = 80, height = NA)
bmi(mass = NA, height = NA)

library(dplyr)
test_that("bmi works", {

  test_that("1. not numeric", {
    expect_error(bmi(mass = 'toto', height = 1.80))
  })

  test_that("2. NA ok", {
    expect_equal(bmi(mass = NA, height = 1.80),NA)
  })

})

# Run but keep eval=FALSE to avoid infinite loop
# Execute in the console directly
fusen::inflate(flat_file = "dev/flat_minimal.Rmd", vignette_name = "Minimal")