Regression testing Issue [make installcheck]

For the regression tests:

The code for the makefile is:

EXTENSION = my_extension
DATA = my_extension--1.0.sql
REGRESS = my_extension--regress.sql

PG_CONFIG  ?= pg_config
PGXS := $(shell $(PG_CONFIG) --pgxs)
include $(PGXS)

Regression testing SQL file my_extension--regress.sql:

-- regression test script for my_extension

-- Create the my_table table
CREATE TABLE my_table (
  id SERIAL PRIMARY KEY,
  name VARCHAR(100) NOT NULL
);

-- Test the my_function function
SELECT my_function();

-- Verify the data in the my_table table
SELECT * FROM my_table;

After running make installcheck on my_extension getting error:

Tried to set the environment variable PGUSER PGUSER=postgres make installcheck

Got the error:

echo "+++ regress install-check in  +++" && /Users/spartacus/.pgenv/pgsql-15.0/lib/pgxs/src/makefiles/../../src/test/regress/pg_regress --inputdir=./ --bindir='/Users/spartacus/.pgenv/pgsql-15.0/bin'    --dbname=contrib_regression my_extension--regress
+++ regress install-check in  +++
(using postmaster on Unix socket, default port)
============== dropping database "contrib_regression" ==============
SET
DROP DATABASE
============== creating database "contrib_regression" ==============
CREATE DATABASE
ALTER DATABASE
ALTER DATABASE
ALTER DATABASE
ALTER DATABASE
ALTER DATABASE
ALTER DATABASE
============== running regression test queries        ==============
test my_extension--regress        ... diff: /Users/spartacus/Desktop/GSoC/CODE/my_extension/expected/my_extension--regress.out: No such file or directory
diff command failed with status 512: diff  "/Users/spartacus/Desktop/GSoC/CODE/my_extension/expected/my_extension--regress.out" "/Users/spartacus/Desktop/GSoC/CODE/my_extension/results/my_extension--regress.out" > "/Users/spartacus/Desktop/GSoC/CODE/my_extension/results/my_extension--regress.out.diff"
make: *** [installcheck] Error 2

Link to the Github issue: https://github.com/IshaanAdarsh/Postgres-extension-tutorial/issues/15 (for more details and the extension code)

You need to provide expected/my_extension--regress.out so that the regression tests have something to compare the actual results with.

Typically, you proceed like this:

• run the regression tests and get the error message you see

• look at results/my_extension--regress.out and see if the output is as it should be

• if you are happy with the results, copy results/my_extension--regress.out to expected/my_extension--regress.out