Make object format less fragile

Matrices inherit from arrays in R-devel.

cran-comments.md

@@ -1,3 +1,7 @@
+This is a resubmission that fixes a failure on R-devel.
+
+---
+
 ## Test environments
 
 * local: darwin15.6.0-3.6.0

tests/testthat/test-object-format.R

@@ -1,32 +1,9 @@
 test_that("format has nice defaults for bare vectors", {
-  expect_equal(
-    call_to_format(x <- list(a = 1, b = 2)),
-    "An object of class \\code{list} of length 2."
-  )
-})
-
-test_that("format defaults for S3 objects", {
-  expect_equal(
-    call_to_format(x <- ordered(letters[1:5])),
-    "An object of class \\code{ordered} (inherits from \\code{factor}) of length 5."
-  )
-})
-
-test_that("format has nice defaults for matrices and arrays", {
-  expect_equal(
-    call_to_format(x <- diag(10)),
-    "An object of class \\code{matrix} with 10 rows and 10 columns."
-  )
-
-  expect_equal(
-    call_to_format(x <- array(1:27, dim = c(3, 3, 3))),
-    "An object of class \\code{array} of dimension 3 x 3 x 3."
-  )
-})
-
-test_that("format has nice defaults for data frames", {
-  expect_equal(
-    call_to_format(x <- data.frame(a = 1, b = 2)),
-    "An object of class \\code{data.frame} with 1 rows and 2 columns."
-  )
+  verify_output(test_path("test-object-format.txt"), {
+    call_to_format(x <- list(a = 1, b = 2))
+    call_to_format(x <- ordered(letters[1:5]))
+    call_to_format(x <- diag(10))
+    call_to_format(x <- array(1:27, dim = c(3, 3, 3)))
+    call_to_format(x <- data.frame(a = 1, b = 2))
+  })
 })

tests/testthat/test-object-format.txt

@@ -0,0 +1,15 @@
+> call_to_format(x <- list(a = 1, b = 2))
+[1] "An object of class \\code{list} of length 2."
+
+> call_to_format(x <- ordered(letters[1:5]))
+[1] "An object of class \\code{ordered} (inherits from \\code{factor}) of length 5."
+
+> call_to_format(x <- diag(10))
+[1] "An object of class \\code{matrix} with 10 rows and 10 columns."
+
+> call_to_format(x <- array(1:27, dim = c(3, 3, 3)))
+[1] "An object of class \\code{array} of dimension 3 x 3 x 3."
+
+> call_to_format(x <- data.frame(a = 1, b = 2))
+[1] "An object of class \\code{data.frame} with 1 rows and 2 columns."
+