Test in Shell!!

sum_function.sh

echo $(( $1 + $2))

test_file.sh

sucess_message="[INFO] test pass"
fail_message="[ERROR] test fail"
file_path="text.txt"

echo "[INFO] Running $file_path IS A FILE CASE:"
test -f $file_path && echo "$sucess_message" || echo "$fail_message"

echo "[INFO] Running $file_path NOT EMPTY CASE:"
test -s $file_path && echo "$sucess_message" || echo "$fail_message"

: <<'NOTES'
Files commands:
-d: Is a directory
-f: Is a file
-r: Is a file with read permission
-s: Is a file with size greater than zero
-w: Is a file with write permission
-nt: The file is newer than
-ot: The file is older than
-ef: Is a equal file
-a: AND logical
-o: OR logical
NOTES

test_sum_function.sh

sum=$(/bin/bash ./sum_function.sh 1 1)
sucess_message="[INFO] test pass"
fail_message="[ERROR] test fail"

echo "[INFO] Running EQUAL CASE sum_function.sh:"
expected_value=2
test "$sum" -eq $expected_value && echo "$sucess_message" || echo "$fail_message"

echo "[INFO] Running NOT EQUAL CASE sum_function.sh:"
unexpected_value=3
test "$sum" -ne $unexpected_value && echo "$sucess_message" || echo "$fail_message"

: <<'NOTES'
Numbers commands:
-lt: Less than
-gt: greater than
-le: less equal
-ge: greater equal
-eq: equal
-ne: not equal

Strings commands:
= : is equal
!= : is different
-n : is not null
-z : is null
NOTES

text.txt

Ronaldo