Add empty file check

Author: ndavidova

tmt/tests/container/sanity/upgrade/upgrade.sh

@@ -29,8 +29,8 @@ su - postgres -c "
 echo \"User switched\";
 
 createdb testdb;
-psql -U postgres -d testdb -c \"create table users (id serial primary key, name text)\";
-psql -U postgres -d testdb -c \"insert into users (name) values ('Alice'), ('Bob'), ('Celine')\"
+psql -h /tmp  -U postgres -d testdb -c \"create table users (id serial primary key, name text)\";
+psql -h /tmp -U postgres -d testdb -c \"insert into users (name) values ('Alice'), ('Bob'), ('Celine')\"
 "
 su - postgres -c '
 psql -U postgres -d testdb -c "select * from users"
@@ -39,6 +39,8 @@ psql -U postgres -d testdb -c "select * from users"
 echo "Expected:"
 cat expected.txt
 
+test $(wc -l < expected.txt) -gt 0 || { echo "ERROR: expected.txt is empty!"; exit 1; }
+
 # uninstall postgresql
 dnf -y remove postgresql-server postgresql-private-libs postgresql libicu
 
@@ -54,10 +56,11 @@ su - postgres -c "
 "
 
 su - postgres -c '
-psql -U postgres -d testdb -c "select * from users"
+psql -h /tmp -U postgres -d testdb -c "select * from users"
 ' > actual.txt
 
 echo "Actual:"
 cat actual.txt
 
 diff -q expected.txt actual.txt && echo "Actual and expected outputs match" || { echo "Actual and expected outputs differ"; exit 1; }
+