effective regression test code example

Example 1: how to create test plan for regression test

in Jira test plan is nothing but grouping tests
(and labeling them )so that they are regression,
smoke or both. All you need to do is create
a test plan name is Regression and add tests
to this test plan by linking those tests with
the test plan you have just created.
So question which scenario goes to regression:
we decide it together as a team, mostly
positive scenarios go to regression,
the ones that needs repeated execution,
retesting once a new build is added.

Example 2: effective regression test

The regression tests should be wide and 
detailed enough to allow catching defects.
You can also eliminate duplicate test
cases, merge test cases and automated tests as feasible.