when to automate test cases code example

Example: test case should be automated

Tests that should not be automated:

Tests that you will only run only once.
The only exception to this rule is that
if you want to execute a test with a very large 
set of data, even if it’s only once,
then it makes sense to automate it.

Tests that need to be run ASAP Usually, 
a new feature which is developed requires
a quick feedback so testing it manually at first
making sense.