tests/testthat/test-rgbmanipulation.R

In UBC-MDS/InstaRF: Image Processing

context("test-rgbmanipulation")

# Copyright 2018 Betty Zhou
# This script contains tests for the RGB_manipulation function

#library(testthat)
#library(png)
#library(InstaRF)
#library(testit)

# test input: colour image
test_img_RGB_manipulation_input <- array(c(c(12, 24, 48,
                                             12, 24, 48,
                                             12, 24, 48),   #R
                                           c(2, 6, 1,
                                             2, 6, 1,
                                             2, 6, 1),   #G
                                           c(51, 12, 24,
                                             51, 12, 24,
                                             51, 12, 24)),  #B
                                         dim = c(3,3,3))

writePNG(test_img_RGB_manipulation_input/255, testthat::test_path("test_img/test_img_RGB_manipulation_input.png"))

# test output: RGB_manipulated image

test_img_RGB_manipulation_ex_output = array(c(c(36, 72, 144,
                                                36, 72, 144,
                                                36, 72, 144),  #R
                                              c(6, 18, 3,
                                                6, 18, 3,
                                                6, 18, 3),   #G
                                              c(153, 36, 72,
                                                153, 36, 72,
                                                153, 36, 72)),  #B
                                            dim = c(3,3,3))

writePNG(test_img_RGB_manipulation_ex_output/255, "test_img/test_img_RGB_manipulation_ex_output.png")

# Check whether RGB_manipulation function is working properly

test_that('function is working properly',{
  RGB_manipulation("test_img/test_img_RGB_manipulation_input.png", R= 3L, G=3L, B=3L, "test_img/RGB_manipulation_output.png")
  RGB_manipulation_output <- readPNG("test_img/RGB_manipulation_output.png") * 255
  expect_equal(RGB_manipulation_output, test_img_RGB_manipulation_ex_output, tolerance = 1e-5)
})

#Handling the exceptions with RGB_manipulation_filter()
test_that('function input is the right type',{
  RGB_manipulation_output <- readPNG("test_img/RGB_manipulation_output.png") * 255
  expect_is(RGB_manipulation_output, 'array')
})

test_that('function output is the right type',{
  RGB_manipulation_output <- readPNG("test_img/RGB_manipulation_output.png") * 255
  expect_is(RGB_manipulation_output, 'array')
})

test_that('function input path is incorrect',{
  expect_error(RGB_manipulation(1234, R= 1L, G=2L, B=3L, "tests/test_img/RGB_manipulation_output.png"))
})

test_that('input type is incorrect',{
  expect_error(RGB_manipulation("tests/test.txt", R= 1L, G=2L, B=3L, "tests/test_img/RGB_manipulation_output.png"))
})

test_that('function input path is incorrect',{
  expect_error(RGB_manipulation("./1234/123.png", R= 1L, G=2L, B=3L, "tests/test_img/RGB_manipulation_output.png"))
})

test_that('function output path is incorrect',{
  expect_error(RGB_manipulation("tests/test_img/test_img_RGB_manipulation_input.png", R= 1L, G=2L, B=3L, 1234))
})