added tests

tests/testthat/test_x3p_crop.R

@@ -5,8 +5,18 @@ test_that("x3p_crop works as expected", {
   # crop to same size
   expect_silent(tmp <- x3ptest_mask %>% x3p_crop(width=6,height=7))
   expect_equal(tmp$general.info$Comment, "cropped from location (1,1)")
+  # offset element should have been added
+  expect_contains(names(tmp), "offset")
+  # offset should have two rows and five columns
+  expect_identical(dim(tmp$offset), c(2L,5L))
+
   # try to crop to larger size
-  expect_warning(tmp <- x3ptest_mask %>% x3p_crop(width=10,height=10))
+  expect_warning(tmp <- x3ptest_mask %>% x3p_crop(2, 2, width=10,height=10))
+  expect_warning(tmp <- tmp %>% x3p_crop(1, 1, width=10,height=10))
+  # second crop should preserve starting location within x3ptest_mask: 
+  expect_equal(tmp$offset$xmin[1], 2)
+  expect_equal(tmp$offset$ymin[1], 2)
+
   # crop to smaller size
   expect_silent(tmp <- x3ptest_mask %>% x3p_crop(width=4,height=4))