4 files changed, 30 insertions, 14 deletions
diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md
index 291e5a2513..0e831bfb66 100644
--- a/activerecord/CHANGELOG.md
+++ b/activerecord/CHANGELOG.md
@@ -1,3 +1,9 @@
+*   Properly accept all valid JSON primitives in the JSON data type.
+
+    Fixes #24234
+
+    *Sean Griffin*
+
 *   MariaDB 5.3+ supports microsecond datetime precision.
 
     *Jeremy Daer*
diff --git a/activerecord/lib/active_record/type/internal/abstract_json.rb b/activerecord/lib/active_record/type/internal/abstract_json.rb
index 097d1bd363..513c938088 100644
--- a/activerecord/lib/active_record/type/internal/abstract_json.rb
+++ b/activerecord/lib/active_record/type/internal/abstract_json.rb
@@ -17,11 +17,7 @@ module ActiveRecord
         end
 
         def serialize(value)
-          if value.is_a?(::Array) || value.is_a?(::Hash)
-            ::ActiveSupport::JSON.encode(value)
-          else
-            value
-          end
+          ::ActiveSupport::JSON.encode(value)
         end
 
         def accessor
diff --git a/activerecord/test/cases/adapters/mysql2/json_test.rb b/activerecord/test/cases/adapters/mysql2/json_test.rb
index c8c933af5e..9c3fef1b59 100644
--- a/activerecord/test/cases/adapters/mysql2/json_test.rb
+++ b/activerecord/test/cases/adapters/mysql2/json_test.rb
@@ -161,12 +161,19 @@ class Mysql2JSONTest < ActiveRecord::Mysql2TestCase
     assert_not json.changed?
   end
 
-  def test_assigning_invalid_json
-    json = JsonDataType.new
+  def test_assigning_string_literal
+    json = JsonDataType.create(payload: "foo")
+    assert_equal "foo", json.payload
+  end
 
-    json.payload = 'foo'
+  def test_assigning_number
+    json = JsonDataType.create(payload: 1.234)
+    assert_equal 1.234, json.payload
+  end
 
-    assert_nil json.payload
+  def test_assigning_boolean
+    json = JsonDataType.create(payload: true)
+    assert_equal true, json.payload
   end
 end
 end
diff --git a/activerecord/test/cases/adapters/postgresql/json_test.rb b/activerecord/test/cases/adapters/postgresql/json_test.rb
index b3b121b4fb..663de680b5 100644
--- a/activerecord/test/cases/adapters/postgresql/json_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/json_test.rb
@@ -38,7 +38,7 @@ module PostgresqlJSONSharedTestCases
   end
 
   def test_default
-    @connection.add_column 'json_data_type', 'permissions', column_type, default: '{"users": "read", "posts": ["read", "write"]}'
+    @connection.add_column 'json_data_type', 'permissions', column_type, default: {"users": "read", "posts": ["read", "write"]}
     JsonDataType.reset_column_information
 
     assert_equal({"users"=>"read", "posts"=>["read", "write"]}, JsonDataType.column_defaults['permissions'])
@@ -178,12 +178,19 @@ module PostgresqlJSONSharedTestCases
     assert_not json.changed?
   end
 
-  def test_assigning_invalid_json
-    json = JsonDataType.new
+  def test_assigning_string_literal
+    json = JsonDataType.create(payload: "foo")
+    assert_equal "foo", json.payload
+  end
 
-    json.payload = 'foo'
+  def test_assigning_number
+    json = JsonDataType.create(payload: 1.234)
+    assert_equal 1.234, json.payload
+  end
 
-    assert_nil json.payload
+  def test_assigning_boolean
+    json = JsonDataType.create(payload: true)
+    assert_equal true, json.payload
   end
 end