Implement Request Validation DTOs for All Endpoints

[LaGodxy]

Description: Create comprehensive Data Transfer Objects (DTOs) with validation rules for all API endpoints to ensure data integrity and security.

Acceptance Criteria:

• Create DTOs for all existing API endpoints
• Implement validation decorators for all input fields
• Add custom validation messages for better user experience
• Add validation for nested objects and arrays
• Update all controllers to use DTOs
• Add validation error handling
• Unit tests for all validation scenarios
• Integration tests for validation endpoints

Files to Modify:

• src/common/dto/ (new directory)
• src/auth/dto/ (new directory)
• src/property/dto/ (new directory)
• src/user/dto/ (new directory)
• Update all controller files
• test/validation/ (new directory)

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This issue has been added to the Stellar Wave Program and is worth 100 Points.

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[rosemary21]

@rosemary21 has applied to work on this issue as part of the Stellar Wave Program's 1st wave.

Why I’d like to work on this issue:
I’m interested in this task because building comprehensive DTOs with proper validation is critical for data integrity, security, and a reliable API experience. Well-structured DTOs enforce correct data types, prevent invalid inputs, and improve maintainability across the backend. I enjoy designing type-safe, secure, and developer-friendly APIs, and this task directly improves platform robustness while making the backend easier to test and extend.

Relevant experience:

Extensive experience creating DTOs in Nest.js/TypeScript, with validation decorators using class-validator and class-transformer.

Implemented nested object and array validation to ensure complex payloads are properly checked.

Designed custom validation messages for enhanced user and developer feedback.

Integrated DTOs into controllers and services to enforce type safety and consistent API contracts.

Developed unit and integration tests to cover validation scenarios and edge cases.

Familiar with error handling patterns for validation failures, returning clear and consistent API responses.

Experience with OpenAPI/Swagger documentation for validated endpoints, improving API discoverability and usability.

Proposed approach for this issue:

Create directories for DTOs:

src/common/dto/

src/auth/dto/

src/property/dto/

src/user/dto/

Define DTO classes for all existing endpoints with validation decorators for strings, numbers, enums, nested objects, and arrays.

Add custom error messages to improve UX when validation fails.

Update controllers to use DTOs in request handling.

Implement global validation error handling to standardize API responses.

Write unit tests covering all validation scenarios.

Write integration tests to ensure endpoints reject invalid payloads and accept valid ones.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @rosemary21 to this issue.

[abdegenius]

@abdegenius has applied to work on this issue as part of the Stellar Wave Program's 1st wave.

I'd love to work on this issue.. I have read and understood the required assignment and will deliver accordingly.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @abdegenius to this issue.

[akintewe]

@akintewe has applied to work on this issue as part of the Stellar Wave Program's 1st wave.

I'm a full-stack developer with 4+ years of experience building complex forms and e-commerce systems. I've previously worked on this project in the past as well as also developed inventory management systems for agricultural businesses and am well-versed in handling image processing and state management at scale.
I would love to work on this issue, my ETA is 3 hours.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @akintewe to this issue.

[drips-wave]

Congratulations, @rosemary21! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on January 31, 2026.

🧑‍💻 @rosemary21: Please resolve the issue such that the repo's maintainers have enough time to review your contribution before the due date. You'll earn Points for completing the issue on-time, which will make you eligible for a share of the Stellar Wave Program's reward pool.

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🤠 Repo maintainers: Please keep an eye on the contributor's progress and review their work before the due date. You can manage this issue, including adjusting its complexity and points, here.

🌊 Happy Wave 🌊

[drips-wave]

This issue has been completed by @rosemary21 as part of the Stellar Wave Program's 1st Wave 🥳

😎 @rosemary21: You earned 100 Points for completing this issue! After the current Wave ends, you'll be eligible for a percentage of the Wave's reward pool based on the percentage of total points you've earned. Learn more here.

🧑‍💻 Repo maintainers: How'd the contributor do? If you like, you can reward them with additional points by making a compliment within seven days after the Wave Program's current wave ends.