Adds expect_that() to undesirable functions linter

NEWS.md

@@ -96,6 +96,8 @@
    + No longer lints undesirable symbols if they are used as names in `$` extractions (#1050, @AshesITR)
    + Added more explanation why certain functions might be undesirable and what alternatives to use;
      ditto for `undesirable_operator_linter()` (#1133, #1146, #1159, @AshesITR)
+   + Added `testthat::expect_that()`, which has been deprecated since the 3rd edition of `{testthat}` 
+     package (#1377, @patilindrajeets)
 * `assignment_linter()` (#915, @MichaelChirico)
    + Right assignments are now linted by default (`->` and `->>`)
    + New argument `allow_cascading_assign` (`TRUE` by default) toggles whether to lint `<<-` and `->>`

R/expect_identical_linter.R

@@ -17,7 +17,7 @@
 #'   1. A named argument is set (e.g. `ignore_attr` or `tolerance`)
 #'   2. Comparison is made to an explicit decimal, e.g.
 #'      `expect_equal(x, 1.0)` (implicitly setting `tolerance`)
-#'   3. `...` is passed (wrapper functions whcih might set
+#'   3. `...` is passed (wrapper functions which might set
 #'      arguments such as `ignore_attr` or `tolerance`)
 #'
 #' @evalRd rd_tags("expect_identical_linter")

R/zzz.R

@@ -55,6 +55,10 @@ default_linters <- modify_defaults(
 #'  * [debugonce()] is only useful for interactive debugging. It should be removed.
 #'  * [detach()] modifies the global search path. Detaching environments from the search path is rarely necessary in
 #'    production code.
+#'  * [testthat::expect_that()] is an old style of writing tests that is no
+#'  longer encouraged, and is deprecated in the 3rd edition of {testthat}
+#'  package. Use specific expect_ functions, e.g. [testthat::expect_equal()] or
+#'  [testthat::expect_s3_class()], instead.
 #'  * [ifelse()] isn't type stable. Use an `if`/`else` block for scalar logic, or use
 #'    `dplyr::if_else()`/`data.table::fifelse()` for type stable vectorized logic.
 #'  * [.libPaths()] permanently modifies the library location. Use [withr::with_libpaths()] for a temporary change
@@ -106,6 +110,11 @@ all_undesirable_functions <- modify_defaults(
   "debugonce" = "It is only useful for interactive debugging. It should be removed.",
   "detach" = paste("It modifies the global search path. Detaching environments from the search path",
                    "is rarely necessary in production code."),
+  "expect_that" = paste("testthat::expect_that() is an old style of writing tests",
+                        "that is no longer encouraged, and is deprecated",
+                        "in the 3rd edition of {testthat} package.",
+                        "Use specific expect_ functions, e.g. testthat::expect_equal() or",
+                        "testthat::expect_s3_class(), instead."),
   "ifelse" = paste("It isn't type stable. Use an `if`/`else` block for scalar logic, or use",
                    "dplyr::if_else()/data.table::fifelse() for type stable vectorized logic."),
   ".libPaths" = paste("It permanently modifies the library location. Use withr::with_libpaths()",
@@ -147,6 +156,7 @@ default_undesirable_functions <- all_undesirable_functions[names(all_undesirable
   "debugcall",
   "debugonce",
   "detach",
+  "expect_that",
   ".libPaths",
   "library",
   "mapply",

tests/testthat/test-undesirable_function_linter.R

@@ -1,4 +1,4 @@
-test_that("linter returns correct linting", {
+test_that("linter returns correct linting for undesirable functions", {
   linter <- undesirable_function_linter(fun = c("return" = NA, "log10" = "use log()"))
   msg_return <- "Function \"return\" is undesirable.$"
   msg_log10 <- "Function \"log10\" is undesirable. As an alternative, use log\\(\\)."