transition expect_error() calls

* ...to snapshot when testing the error message
* ...to classed error when testing an error from another package or an error thrown from a widely-used helper
* ...to `expect_no_error()` (or no test) when `regex = NA`
* analogous story for `expect_warning()` and `expect_message()`.

tests/testthat/test-broom.R

@@ -165,8 +165,7 @@ test_that("augment fails if it can't preprocess `new_data`", {
 
   wf <- fit(wf, df)
 
-  # vctrs type error
-  expect_error(augment(wf, new_data))
+  expect_error(augment(wf, new_data), class = "vctrs_error_cast")
 })
 
 test_that("augment works with matrix compositions (#148)", {

tests/testthat/test-pre-action-case-weights.R

@@ -478,8 +478,7 @@ test_that("case weights `col` must exist in `data`", {
   wf <- add_formula(wf, mpg ~ .)
   wf <- add_case_weights(wf, foo)
 
-  # Tidyselect error
-  expect_error(fit(wf, mtcars))
+  expect_error(fit(wf, mtcars), class = "vctrs_error_subscript_oob")
 })
 
 test_that("case weights `col` can't select >1 columns in `data`", {

tests/testthat/test-pre-action-variables.R

@@ -168,8 +168,7 @@ test_that("`outcomes` are removed from set of possible `predictors` (#72)", {
 
   workflow2 <- add_variables(workflow, mpg, mpg)
 
-  # vctrs subscript error
-  expect_error(.fit_pre(workflow2, mtcars))
+  expect_error(.fit_pre(workflow2, mtcars), class = "vctrs_error_subscript_oob")
 })
 
 test_that("selecting no `outcomes` doesn't break selection of `predictors`", {

tests/testthat/test-predict.R

@@ -120,8 +120,9 @@ test_that("blueprint will get passed on to hardhat::forge()", {
   mod1 <- fit(workflow1, train)
   mod2 <- fit(workflow2, train)
 
+  # Warning from hardhat, so we don't snapshot it
   expect_warning(pred1 <- predict(mod1, test))
-  expect_warning(pred2 <- predict(mod2, test), NA)
+  expect_no_warning(pred2 <- predict(mod2, test))
 
   expect_identical(
     pred1[[".pred"]],