Add deprecator-only overload for assert_deprecated

This commits adds a deprecator-only overload for `assert_deprecated`.
For example, `assert_deprecated(/./, deprecator)` can now be written as
`assert_deprecated(deprecator)`.

This is part of an initiative to move away from the top-level
`ActiveSupport::Deprecation` API, towards per-library deprecator
instances.  See also rails#46000 and its follow-ups.

activesupport/lib/active_support/testing/deprecation.rb

@@ -5,6 +5,13 @@
 module ActiveSupport
   module Testing
     module Deprecation
+      ##
+      # :call-seq:
+      #   assert_deprecated(&block)
+      #   assert_deprecated(match, &block)
+      #   assert_deprecated(deprecator, &block)
+      #   assert_deprecated(match, deprecator, &block)
+      #
       # Asserts that a matching deprecation warning was emitted by the given deprecator during the execution of the yielded block.
       #
       #   assert_deprecated(/foo/, CustomDeprecator) do
@@ -19,7 +26,7 @@ module Deprecation
       #
       # If the +match+ is omitted (or explicitly +nil+), any deprecation warning will match.
       #
-      #   assert_deprecated(nil, CustomDeprecator) do
+      #   assert_deprecated(CustomDeprecator) do
       #     CustomDeprecator.warn "foo should no longer be used"
       #   end
       #
@@ -29,6 +36,7 @@ module Deprecation
       #     ActiveSupport::Deprecation.warn "foo should no longer be used"
       #   end
       def assert_deprecated(match = nil, deprecator = nil, &block)
+        match, deprecator = nil, match if match.is_a?(ActiveSupport::Deprecation)
         result, warnings = collect_deprecations(deprecator, &block)
         assert !warnings.empty?, "Expected a deprecation warning within the block but received none"
         if match

activesupport/test/deprecation/deprecators_test.rb

@@ -125,6 +125,6 @@ def assert_silencing(deprecator)
     end
 
     def assert_not_silencing(deprecator)
-      assert_deprecated(/./, deprecator) { deprecator.warn }
+      assert_deprecated(deprecator) { deprecator.warn }
     end
 end

activesupport/test/deprecation_test.rb

@@ -33,6 +33,10 @@ def setup
     assert_deprecated(/fubar/, @deprecator) do
       @deprecator.warn("using fubar is deprecated")
     end
+
+    assert_deprecated(@deprecator) do
+      @deprecator.warn("whatever")
+    end
   end
 
   test "assert_not_deprecated" do
@@ -303,7 +307,7 @@ def setup
 
   test "assert_deprecated raises when no deprecation warning" do
     assert_raises(Minitest::Assertion) do
-      assert_deprecated(/./, @deprecator) { 1 + 1 }
+      assert_deprecated(@deprecator) { 1 + 1 }
     end
   end
 
@@ -347,7 +351,7 @@ def setup
       assert_not_deprecated(@deprecator) { @deprecator.warn }
     end
 
-    assert_deprecated(/./, @deprecator) { @deprecator.warn }
+    assert_deprecated(@deprecator) { @deprecator.warn }
 
     @deprecator.silenced = true
     assert @deprecator.silenced
@@ -364,21 +368,21 @@ def setup
       @deprecator.silence { raise }
     end
 
-    assert_deprecated(/./, @deprecator) { @deprecator.warn }
+    assert_deprecated(@deprecator) { @deprecator.warn }
   end
 
   test "silence only affects the current thread" do
     @deprecator.silence do
       assert_not_deprecated(@deprecator) { @deprecator.warn }
 
       Thread.new do
-        assert_deprecated(/./, @deprecator) { @deprecator.warn }
+        assert_deprecated(@deprecator) { @deprecator.warn }
 
         @deprecator.silence do
           assert_not_deprecated(@deprecator) { @deprecator.warn }
         end
 
-        assert_deprecated(/./, @deprecator) { @deprecator.warn }
+        assert_deprecated(@deprecator) { @deprecator.warn }
       end.join
 
       assert_not_deprecated(@deprecator) { @deprecator.warn }
@@ -389,8 +393,8 @@ def setup
     klass = Class.new(Deprecatee)
     klass.deprecate :fubar, :fubar=, deprecator: @deprecator
 
-    assert_deprecated(/./, @deprecator) { klass.new.fubar }
-    assert_deprecated(/./, @deprecator) { klass.new.fubar = :foo }
+    assert_deprecated(@deprecator) { klass.new.fubar }
+    assert_deprecated(@deprecator) { klass.new.fubar = :foo }
   end
 
   test "Module::deprecate with alternative method" do
@@ -583,10 +587,10 @@ def method
 
   test "disallowed_warnings with the default warning message" do
     @deprecator.disallowed_warnings = :all
-    assert_disallowed(/./, @deprecator) { @deprecator.warn }
+    assert_disallowed(@deprecator) { @deprecator.warn }
 
     @deprecator.disallowed_warnings = ["fubar"]
-    assert_deprecated(/./, @deprecator) { @deprecator.warn }
+    assert_deprecated(@deprecator) { @deprecator.warn }
   end
 
   test "disallowed_behavior callbacks" do
@@ -600,10 +604,10 @@ def method
   test "allow" do
     @deprecator.disallowed_warnings = :all
 
-    assert_disallowed(/./, @deprecator) { @deprecator.warn }
+    assert_disallowed(@deprecator) { @deprecator.warn }
 
     @deprecator.allow do
-      assert_deprecated(/./, @deprecator) { @deprecator.warn }
+      assert_deprecated(@deprecator) { @deprecator.warn }
     end
   end
 
@@ -641,29 +645,29 @@ def method
     @deprecator.disallowed_warnings = :all
 
     @deprecator.allow do
-      assert_deprecated(/./, @deprecator) { @deprecator.warn }
+      assert_deprecated(@deprecator) { @deprecator.warn }
     end
 
-    assert_disallowed(/./, @deprecator) { @deprecator.warn }
+    assert_disallowed(@deprecator) { @deprecator.warn }
   end
 
   test "allow only affects the current thread" do
     @deprecator.disallowed_warnings = :all
 
     @deprecator.allow do
-      assert_deprecated(/./, @deprecator) { @deprecator.warn }
+      assert_deprecated(@deprecator) { @deprecator.warn }
 
       Thread.new do
-        assert_disallowed(/./, @deprecator) { @deprecator.warn }
+        assert_disallowed(@deprecator) { @deprecator.warn }
 
         @deprecator.allow do
-          assert_deprecated(/./, @deprecator) { @deprecator.warn }
+          assert_deprecated(@deprecator) { @deprecator.warn }
         end
 
-        assert_disallowed(/./, @deprecator) { @deprecator.warn }
+        assert_disallowed(@deprecator) { @deprecator.warn }
       end.join
 
-      assert_deprecated(/./, @deprecator) { @deprecator.warn }
+      assert_deprecated(@deprecator) { @deprecator.warn }
     end
   end
 
@@ -695,11 +699,11 @@ def method
     @deprecator.disallowed_warnings = :all
 
     @deprecator.allow(:all) do
-      assert_deprecated(/./, @deprecator) { @deprecator.warn }
+      assert_deprecated(@deprecator) { @deprecator.warn }
     end
 
     @deprecator.allow(["fubar"]) do
-      assert_disallowed(/./, @deprecator) { @deprecator.warn }
+      assert_disallowed(@deprecator) { @deprecator.warn }
     end
   end
 
@@ -736,6 +740,7 @@ def with_rails_logger(logger)
 
     # a la collect_deprecations
     def collect_disallowed(deprecator)
+      deprecator ||= ActiveSupport::Deprecation
       original_disallowed_behavior = deprecator.disallowed_behavior
       disallowed = []
       deprecator.disallowed_behavior = proc { |message| disallowed << message }
@@ -746,7 +751,8 @@ def collect_disallowed(deprecator)
     end
 
     # a la assert_deprecated
-    def assert_disallowed(match = nil, deprecator = ActiveSupport::Deprecation, &block)
+    def assert_disallowed(match = nil, deprecator = nil, &block)
+      match, deprecator = nil, match if match.is_a?(ActiveSupport::Deprecation)
       result, disallowed = collect_disallowed(deprecator, &block)
       assert_not_empty disallowed, "Expected a disallowed deprecation within the block but received none"
       if match