feat: add validation for contact form input fields

[om-dev007]

Description

This PR improves server-side validation for the contact form endpoint by validating the submitted input before processing email requests.

Changes Made

• Added email format validation using a regular expression.

• Added minimum and maximum length validation for the name field.

• Added minimum and maximum length validation for the subject field.

• Added minimum and maximum length validation for the message field.

• Trimmed user input before validation and email processing.

• Returns 400 Bad Request with descriptive error messages for invalid input.

• Reused validated values when composing the email.

Validation Rules

Field | Validation -- | -- Name | Required, trimmed, 2–50 characters Email | Required, valid email format Subject | Required, trimmed, 5–100 characters Message | Required, trimmed, 10–1000 characters

Benefits

• Prevents malformed or invalid submissions.

• Improves data quality before sending emails.

• Reduces unnecessary email processing.

• Provides clearer feedback to users.

• Maintains backward compatibility with the existing endpoint.

Testing

• ✅ Verified valid requests are processed successfully.

• ✅ Verified invalid email addresses return 400 Bad Request.

• ✅ Verified empty or whitespace-only fields are rejected.

• ✅ Verified name, subject, and message length constraints.

• ✅ Confirmed email sending functionality remains unchanged.

Closes #72

[vercel]

@om-dev007 is attempting to deploy a commit to the Bindupautra Jyotibrat's projects Team on Vercel.

A member of the Team first needs to authorize it.

[om-dev007]

Hi @Jyotibrat,
I've addressed issue #72 by adding server-side validation for all contact form fields, including email format validation, length checks, and input trimming while keeping the existing functionality intact.
The only failing checks are Vercel deployment checks, which appear to require repository authorization from the project owner. The code changes themselves are complete, and the security check has passed successfully.
Whenever you have time, I'd appreciate it if you could review the PR. Thank you!

[Jyotibrat]

Hi @Jyotibrat, I've addressed issue #72 by adding server-side validation for all contact form fields, including email format validation, length checks, and input trimming while keeping the existing functionality intact. The only failing checks are Vercel deployment checks, which appear to require repository authorization from the project owner. The code changes themselves are complete, and the security check has passed successfully. Whenever you have time, I'd appreciate it if you could review the PR. Thank you!

I'll review the PR and get back to you

[om-dev007]

@Jyotibrat ok thank you for giving your valuable time

[Jyotibrat]

The backend logic works perfectly fine. But, can you add the response to the frontend so that the user knows what is wrong with the message that he/she is typing.

Thank You for your contribution @om-dev007 .

[om-dev007]

Hi @Jyotibrat,
Thank you for the review and feedback.
The current PR was focused on adding server-side validation for the contact form fields as described in issue #72. The backend now returns specific validation error messages for invalid input.
Since showing those validation messages in the UI would require frontend changes as well, I wanted to confirm whether you would like that to be included as part of this PR, or handled in a separate follow-up issue/PR.
I can proceed accordingly. Thank you!

[Jyotibrat]

Hi @Jyotibrat, Thank you for the review and feedback. The current PR was focused on adding server-side validation for the contact form fields as described in issue #72. The backend now returns specific validation error messages for invalid input. Since showing those validation messages in the UI would require frontend changes as well, I wanted to confirm whether you would like that to be included as part of this PR, or handled in a separate follow-up issue/PR. I can proceed accordingly. Thank you!

Raise a separate issue for that and I will assign it to you. Once your frontend PR will be raised then I will check both backend and frontend PR together and merged it if it works.

[om-dev007]

Hi @Jyotibrat,
Thank you for the clarification.
At the moment, I won’t be able to take up the frontend follow-up issue/PR, so please feel free to assign it to someone else if needed.
If the backend validation changes in this PR are still useful on their own, I’d be happy for them to be considered separately. Otherwise, I completely understand if you’d prefer to review/merge both together after the frontend work is completed.
Thanks again for your time.