---

name: fix-interface description: Fix Interface and Controller compilation errors allowed-tools: Read, Edit, Write, Bash, Grep, Glob

Fix Interface Errors

Fix interface and controller compilation errors according to code conventions.

FORBIDDEN

NEVER use:

• as keyword (type assertion)
• any type

Fix type issues by properly defining interfaces.

DO NOT MODIFY

Leave as-is:

• console.log in Controller catch blocks
• console.error in Controller catch blocks

These are intentional and should not be changed to NestJS Logger.

---

Purpose

Fix compilation errors in interface and controller files to ensure npm run build:main passes.

Workflow

┌─────────────────────────────────────┐
│  Step 1: Run Build                  │
│  npm run build:main                 │
└───────────────┬─────────────────────┘
                │
                ▼
┌─────────────────────────────────────┐
│  Step 2: Parse Interface Errors     │
│  - Empty interfaces {}              │
│  - Type mismatches                  │
│  - Missing properties               │
└───────────────┬─────────────────────┘
                │
                ▼
┌─────────────────────────────────────┐
│  Step 3: Fix by Convention          │
│  - Fill empty interfaces            │
│  - Add typia tags                   │
│  - Fix nullable types               │
└───────────────┬─────────────────────┘
                │
                ▼
┌─────────────────────────────────────┐
│  Step 4: Re-run Build               │
│  Loop until 0 errors                │
└─────────────────────────────────────┘

---

Step 1: Run Build

npm run build:main 2>&1 | head -100

Capture interface-related errors.

---

Step 2: Parse Errors

Common error patterns:

• Type '{}' is not assignable → Empty interface
• Property 'X' does not exist on type '{}' → Empty interface
• Type 'string' is not assignable to type 'string & Format<"uuid">' → Missing typia tag

---

Step 3: Fix by Convention

Empty Interface Fix

Read Prisma schema and fill interface:

// Before
export type IEntity = {};

// After
import { tags } from "typia";

export type IEntity = {
  id: string & tags.Format<"uuid">;
  name: string;
  status: "active" | "inactive";
  created_at: string & tags.Format<"date-time">;
  updated_at: string & tags.Format<"date-time">;
  deleted_at: (string & tags.Format<"date-time">) | null;
};

ICreate Convention

export namespace IEntity {
  export type ICreate = {
    name: string;
    status?: "active" | "inactive";  // optional with default
  };
}

IUpdate Convention

export namespace IEntity {
  export type IUpdate = {
    name?: string;
    status?: "active" | "inactive";
  };
}

ISummary Convention

export namespace IEntity {
  export type ISummary = {
    id: string & tags.Format<"uuid">;
    name: string;
    status: "active" | "inactive";
    created_at: string & tags.Format<"date-time">;
  };
}

IRequest Convention

export namespace IEntity {
  export type IRequest = {
    page?: number & tags.Minimum<1>;
    limit?: number & tags.Minimum<1> & tags.Maximum<100>;
    search?: string;
    status?: "active" | "inactive";
  };
}

Typia Tags

// UUID
id: string & tags.Format<"uuid">;

// Email
email: string & tags.Format<"email">;

// URL
url: string & tags.Format<"uri">;

// DateTime
created_at: string & tags.Format<"date-time">;

// Numeric constraints
page: number & tags.Minimum<1>;
limit: number & tags.Minimum<1> & tags.Maximum<100>;

Nullable Types

// Nullable field
deleted_at: (string & tags.Format<"date-time">) | null;

// Optional nullable field
description?: string | null;

Path Naming Fix

Fix redundant path segments where the same word repeats:

// Before - redundant word in path: /{word}/{word}s
@Controller("{prefix}/{word}/{word}s")
export class {Word}{Word}sController { ... }

// After - remove redundant segment
@Controller("{prefix}/{word}s")
export class {Word}sController { ... }

Pattern to fix:

• /{word}/{word}s → /{word}s
• /{word}/{word}-* → /{word}-* or /{word}/*

When fixing paths, also update:

1. Controller @Controller() decorator
2. Controller class name
3. Controller file name and directory
4. Related provider function names
5. Test file paths and API calls

---

Step 4: Verify

npm run build:main

Repeat Steps 2-4 until no interface errors.

---

Common Fixes

| Error Pattern | Fix | |---------------|-----| | Empty interface {} | Read Prisma schema, define all fields | | Missing typia tag | Add appropriate tags.Format<> | | Nullable mismatch | Add \| null for nullable fields | | Missing namespace | Add namespace with ICreate, IUpdate, etc. | | Redundant path /{word}/{word}s | Remove duplication: /{word}s |

---

Exit Condition

• npm run build:main completes with no interface errors
• All interfaces properly defined
• All typia tags applied
• No redundant path segments (/{word}/{word}s pattern)