Fix local_edition ambiguity in tests

This appears to cause errors when running tests within some interactive
sessions, e.g., from running tests (attaching `testthat`), then
`library(tidyverse)` (attaching `readr` and masking `local_edition` even if
`testthat` is re-`library`-ied in), then attempting to run tests again.

Author: lcbrooks

tests/testthat/test-epix_fill_through_version.R

@@ -11,9 +11,10 @@ test_that("epix_fill_through_version mirrors input when it is sufficiently up to
   # edition 3, which is based on `waldo::compare` rather than `base::identical`;
   # `waldo::compare` in waldo >=0.3.1 appears (as of 0.4.0) to compare R6
   # objects by contents rather than address (in a way that is tested but maybe
-  # not guaranteed via user docs). Use `local_edition` to ensure we use edition
-  # 3 here.
-  local_edition(3)
+  # not guaranteed via user docs). Use `testthat::local_edition` to ensure we
+  # use testthat edition 3 here (use `testthat::` to prevent ambiguity with
+  # `readr`).
+  testthat::local_edition(3)
   expect_identical(ea_orig, ea_trivial_fill_na1)
   expect_identical(ea_orig, ea_trivial_fill_na2)
   expect_identical(ea_orig, ea_trivial_fill_locf)
@@ -30,9 +31,9 @@ test_that("epix_fill_through_version can extend observed versions, gives expecte
   ea_fill_na = epix_fill_through_version(ea_orig, later_unobserved_version, "na")
   ea_fill_locf = epix_fill_through_version(ea_orig, later_unobserved_version, "locf")
 
-  # We use edition 3 features here, passing `ignore_attr` to `waldo::compare`.
-  # Ensure we are using edition 3:
-  local_edition(3)
+  # We use testthat edition 3 features here, passing `ignore_attr` to
+  # `waldo::compare`. Ensure we are using edition 3:
+  testthat::local_edition(3)
   withCallingHandlers({
     expect_identical(ea_fill_na$versions_end, later_unobserved_version)
     expect_identical(tibble::as_tibble(ea_fill_na$as_of(first_unobserved_version)),

tests/testthat/test-epix_merge.R

@@ -58,7 +58,7 @@ test_that("epix_merge merges and carries forward updates properly", {
   )
   # We rely on testthat edition 3 expect_identical using waldo, not identical. See
   # test-epix_fill_through_version.R comments for details.
-  local_edition(3)
+  testthat::local_edition(3)
   expect_identical(xy, xy_expected)
 })