Fix improper syntax with spread operator (#9441)
Fix improper syntax with spread operator (#9441)

* Fix improper syntax with spread operator

currently the example shows incorrect JS syntax wherein an object is included within an object. 

this change fixes by using the spread operator `...`. 

it might be clearer to the user to not include `deleteDog` as a variable, but rather just put it directly into the mock results.

* Update docs/source/development-testing/testing.mdx

* Update docs/source/development-testing/testing.mdx

Co-authored-by: JV <80eeb13d076fdfeb5e381c8b50dd83e8d5b26f46@apollographql.com>
apollographql/apollo-client,apollographql/apollo-client