Deprecate implicit coercion of `ActiveSupport::Duration`

Currently `ActiveSupport::Duration` implicitly converts to a seconds
value when used in a calculation except for the explicit examples of
addition and subtraction where the duration is the receiver, e.g:

    >> 2 * 1.day
    => 172800

This results in lots of confusion especially when using durations
with dates because adding/subtracting a value from a date treats
integers as a day and not a second, e.g:

    >> Date.today
    => Wed, 01 Mar 2017
    >> Date.today + 2 * 1.day
    => Mon, 10 Apr 2490

To fix this we're implementing `coerce` so that we can provide a
deprecation warning with the intent of removing the implicit coercion
in Rails 5.2, e.g:

    >> 2 * 1.day
    DEPRECATION WARNING: Implicit coercion of ActiveSupport::Duration
    to a Numeric is deprecated and will raise a TypeError in Rails 5.2.
    => 172800

In Rails 5.2 it will raise `TypeError`, e.g:

    >> 2 * 1.day
    TypeError: ActiveSupport::Duration can't be coerced into Integer

This is the same behavior as with other types in Ruby, e.g:

    >> 2 * "foo"
    TypeError: String can't be coerced into Integer
    >> "foo" * 2
    => "foofoo"

As part of this deprecation add `*` and `/` methods to `AS::Duration`
so that calculations that keep the duration as the receiver work
correctly whether the final receiver is a `Date` or `Time`, e.g:

    >> Date.today
    => Wed, 01 Mar 2017
    >> Date.today + 1.day * 2
    => Fri, 03 Mar 2017

Fixes #27457.

1 files changed, 1 insertions, 1 deletions

diff --git a/actionview/test/template/date_helper_test.rb b/actionview/test/template/date_helper_test.rb
index bfd3ecd6fd..d257147e1f 100644
--- a/actionview/test/template/date_helper_test.rb
+++ b/actionview/test/template/date_helper_test.rb
@@ -832,7 +832,7 @@ class DateHelperTest < ActionView::TestCase
 
   def test_select_date_with_too_big_range_between_start_year_and_end_year
     assert_raise(ArgumentError) { select_date(Time.mktime(2003, 8, 16), start_year: 2000, end_year: 20000, prefix: "date[first]", order: [:month, :day, :year]) }
-    assert_raise(ArgumentError) { select_date(Time.mktime(2003, 8, 16), start_year: Date.today.year - 100.years, end_year: 2000, prefix: "date[first]", order: [:month, :day, :year]) }
+    assert_raise(ArgumentError) { select_date(Time.mktime(2003, 8, 16), start_year: 100, end_year: 2000, prefix: "date[first]", order: [:month, :day, :year]) }
   end
 
   def test_select_date_can_have_more_then_1000_years_interval_if_forced_via_parameter