Restore RecordNotFound when *_ids= can't find records by ID

9c9fb19b changed the behaviour of the _ids= setters for associations to
raise an AssociationTypeMismatch when unknown IDs are given:

    Class: <ActiveRecord::AssociationTypeMismatch>
    Message: <"Developer(#43811860) expected, got NilClass(#16732720)">

This restores the original ActiveRecord::RecordNotFound exception with a
much clearer error message:

    Class: <ActiveRecord::RecordNotFound>
    Message: <"Couldn't find all Developers with 'id': (1, -9999) [WHERE \"contracts\".\"company_id\" = ?] (found 1 results, but was looking for 2)">

Fixes #25719

activerecord/CHANGELOG.md

+*   Raise ActiveRecord::RecordNotFound from collection `*_ids` setters
+    for unknown IDs with a better error message.
+
+    *Dominic Cleal*
+
 *   For PostgreSQL >= 9.4 use `pgcrypto`'s `gen_random_uuid()` instead of
     `uuid-ossp`'s UUID generation function.
 

activerecord/lib/active_record/associations/collection_association.rb

@@ -73,8 +73,12 @@ def ids_writer(ids)
         ids.map! { |i| pk_type.cast(i) }
         records = klass.where(reflection.association_primary_key => ids).index_by do |r|
           r.send(reflection.association_primary_key)
-        end.values_at(*ids)
-        replace(records)
+        end.values_at(*ids).compact
+        if records.size != ids.size
+          scope.raise_record_not_found_exception!(ids, records.size, ids.size, reflection.association_primary_key)
+        else
+          replace(records)
+        end
       end
 
       def reset

activerecord/lib/active_record/relation/finder_methods.rb

@@ -345,7 +345,7 @@ def exists?(conditions = :none)
     # of results obtained should be provided in the +result_size+ argument and
     # the expected number of results should be provided in the +expected_size+
     # argument.
-    def raise_record_not_found_exception!(ids = nil, result_size = nil, expected_size = nil) # :nodoc:
+    def raise_record_not_found_exception!(ids = nil, result_size = nil, expected_size = nil, key = primary_key) # :nodoc:
       conditions = arel.where_sql(@klass.arel_engine)
       conditions = " [#{conditions}]" if conditions
       name = @klass.name
@@ -355,10 +355,10 @@ def raise_record_not_found_exception!(ids = nil, result_size = nil, expected_siz
         error << " with#{conditions}" if conditions
         raise RecordNotFound.new(error, name)
       elsif Array(ids).size == 1
-        error = "Couldn't find #{name} with '#{primary_key}'=#{ids}#{conditions}"
-        raise RecordNotFound.new(error, name, primary_key, ids)
+        error = "Couldn't find #{name} with '#{key}'=#{ids}#{conditions}"
+        raise RecordNotFound.new(error, name, key, ids)
       else
-        error = "Couldn't find all #{name.pluralize} with '#{primary_key}': "
+        error = "Couldn't find all #{name.pluralize} with '#{key}': "
         error << "(#{ids.join(", ")})#{conditions} (found #{result_size} results, but was looking for #{expected_size})"
 
         raise RecordNotFound.new(error, name, primary_key, ids)

activerecord/test/cases/associations/has_many_through_associations_test.rb

@@ -886,7 +886,8 @@ def test_collection_singular_ids_setter_with_string_primary_keys
   def test_collection_singular_ids_setter_raises_exception_when_invalid_ids_set
     company = companies(:rails_core)
     ids = [Developer.first.id, -9999]
-    assert_raises(ActiveRecord::AssociationTypeMismatch) { company.developer_ids = ids }
+    e = assert_raises(ActiveRecord::RecordNotFound) { company.developer_ids = ids }
+    assert_match(/Couldn't find all Developers with 'id'/, e.message)
   end
 
   def test_build_a_model_from_hm_through_association_with_where_clause