nestjs-feature

NestJS Feature

Purpose

Implement backend functionality that integrates naturally with the existing NestJS architecture.

Prioritize consistency with the repository over introducing new patterns.

Workflow

1. Understand the request

Identify:

• business objective;
• expected behavior;
• affected module;
• existing API contracts;
• authorization requirements;
• validation requirements;
• persistence impact.

Do not begin implementation until the requested behavior is understood.

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2. Inspect the repository

Inspect:

• the affected module;
• one similar implementation;
• existing DTOs;
• services;
• controllers;
• repositories;
• guards;
• interceptors;
• exception handling;
• validation strategy.

Follow the repository conventions.

Avoid introducing a different architectural style.

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3. Design the change

Determine:

• required endpoints;
• request DTOs;
• response DTOs;
• service methods;
• repository operations;
• business rules;
• validation;
• authorization;
• transactions;
• error handling.

Prefer extending existing modules over creating unnecessary ones.

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4. Implement

Keep responsibilities clear.

Controllers should:

• validate requests;
• invoke services;
• return responses.

Services should:

• contain business logic;
• coordinate persistence;
• call integrations.

Repositories should:

• access persistence;
• avoid business logic.

Reuse existing utilities whenever possible.

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5. Validation

Verify:

• request validation;
• authorization;
• persistence;
• response contracts;
• error handling.

Check edge cases.

Avoid introducing breaking API changes unless explicitly requested.

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6. Tests

When practical:

• update existing tests;
• add focused tests for new behavior;
• verify regression coverage.

Avoid testing implementation details.

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7. Review

Inspect the final change.

Verify:

• consistency;
• unnecessary duplication;
• dead code;
• unused imports;
• naming consistency;
• backwards compatibility.