tests/testthat/test-read-bitmap.R

In readbitmap: Simple Unified Interface to Read Bitmap Images (BMP,JPEG,PNG,TIFF)

context("Reading images with read.bitmap")

library(pixmap)
library(jpeg)
library(bmp)
library(png)
library(tiff)

test_that("read.bitmap can load real bmp, jpg, png, tif, tiff files", {
      imgfile="testdata/real.bmp"
      expect_that(read.bitmap(imgfile),
          equals(read.bmp(imgfile)),info='bmp problem')
      imgfile="testdata/real.jpg"
      expect_that(read.bitmap(imgfile),
          equals(readJPEG(imgfile)),info='jpg problem')
      imgfile="testdata/real.png"
      expect_that(read.bitmap(imgfile),
          equals(readPNG(imgfile)),info='png problem')
      imgfile="testdata/real.tif"
      expect_that(read.bitmap(imgfile),
                  equals(readTIFF(imgfile)),
                  info='tif problem')
      imgfile="testdata/real.tiff"
      expect_that(read.bitmap(imgfile),
                  equals(readTIFF(imgfile)),info='tif problem')
})

test_that("read.bitmap can load a bmp pretending to be a jpg", {
      jpgfile="testdata/bmp-pretending-to-be.jpg"
      bmp=read.bitmap(jpgfile)
      bmp2=read.bmp(jpgfile)
      expect_that(bmp,equals(bmp2))
    })

test_that("read.bitmap errors out loading fake bmp when identifying by extension", {
      jpgfile="testdata/bmp-pretending-to-be.jpg"
      expect_that(read.bitmap(jpgfile, IdentifyByExtension = TRUE),
          throws_error('Not a JPEG file'))
    })

test_that("read.bitmap errors out loading fake jpg when identifying by extension", {
  jpgfile="testdata/tiff-pretending-to-be.jpg"
  expect_that(read.bitmap(jpgfile, IdentifyByExtension = TRUE),
              throws_error('Not a JPEG file'))
})

test_that("read.bitmap errors out loading a pnm file (not implemented)", {
      imgfile="testdata/real.pnm"
      expect_that(read.bitmap(imgfile),throws_error())
      expect_that(read.bitmap(imgfile, IdentifyByExtension = TRUE),
          throws_error('does not appear to be a'))
    })

test_that("read.bitmap can load a real jpeg identified by extension", {
      jpgfile="testdata/real.jpg"
      expect_that(read.bitmap(jpgfile, IdentifyByExtension = TRUE),
          equals(readJPEG(jpgfile)))
    })

test_that("read.bitmap can load a real png identified by extension", {
      pngfile="testdata/real.png"
      expect_that(read.bitmap(pngfile, IdentifyByExtension = TRUE),
          equals(readPNG(pngfile)))
    })

test_that("read.bitmap can load a real bmp identified by extension", {
      imgfile="testdata/real.bmp"
      expect_that(read.bitmap(imgfile, IdentifyByExtension = TRUE),
          equals(read.bmp(imgfile)))
    })

test_that("read.bitmap can load a real tiff identified by extension", {
  imgfile="testdata/real.tif"
  expect_that(read.bitmap(imgfile, IdentifyByExtension = TRUE),
              equals(readTIFF(imgfile)))
  imgfile="testdata/real.tiff"
  expect_that(read.bitmap(imgfile, IdentifyByExtension = TRUE),
              equals(readTIFF(imgfile)))
})