Add initial tests for point_offset

R/util-point_offset.r

@@ -66,8 +66,11 @@ point_offset <- function(lon = NA, lat = NA, offsetDist = NA, offsetDir = NA,
 
     lat2 <- 180/pi * lat2
 
-    coords <- matrix(c(lon2, lat2), ncol = 2)
-    colnames(coords) <- c('lon', 'lat')
+    coords <- matrix(
+      c(lon2, lat2),
+      ncol = 2,
+      dimnames = list(NULL, c('lon', 'lat'))
+    )
 
     return(coords)
   }

tests/testthat/test-point_offset.R

@@ -0,0 +1,69 @@
+test_that("Returns named matrix", {
+  expect_type(point_offset(lon = -83.0, lat = 44.0), 'double')
+  expect_vector(point_offset(lon = -83.0, lat = 44.0))
+
+  # No inputs
+  expect_type(point_offset(), 'double')
+
+  expect_identical(
+    colnames(point_offset(lon = -83.0, lat = 44.0)),
+    c('lon', 'lat')
+  )
+})
+
+
+
+
+test_that("Converts feet to meters", {
+  expect_equal(
+    point_offset(lon = -83.0, lat = 44.0, offsetDist = 100,
+                 offsetDir = 'NE', distUnit = 'ft'),
+    matrix(c(-82.99973, 44.00019),
+           ncol = 2,
+           dimnames = list(NULL, c('lon', 'lat'))),
+    tolerance = 1e-5
+  )
+
+  expect_false(
+    identical(
+      point_offset(lon = -83.0, lat = 44.0, offsetDist = 100,
+                   offsetDir = 'NE', distUnit = 'm'),
+      point_offset(lon = -83.0, lat = 44.0, offsetDist = 100,
+                   offsetDir = 'NE', distUnit = 'ft')
+    )
+  )
+})
+
+
+
+
+test_that("Errors with wrong units", {
+  expect_error(
+    point_offset(lon = -83.0, lat = 44.0, offsetDist = 100,
+                 offsetDir = 'NE', distUnit = 'km'),
+    "Input attribute 'dirUnit' must be 'm' \\(meters\\) or 'ft' \\(feet\\)\\."
+  )
+})
+
+
+
+
+test_that("No input returns NA", {
+  # No distance
+  expect_true(
+    all(
+      is.na(
+        point_offset(lon = -83.0, lat = 44.0, offsetDir = 'NE')
+      )
+    )
+  )
+
+  # No direction
+  expect_true(
+    all(
+      is.na(
+        point_offset(lon = -83.0, lat = 44.0, offsetDist = 100)
+      )
+    )
+  )
+})