# Naming conventions consistent

- **Pattern:** `ab-002159` (`code-quality-essentials.organization.naming-conventions`)
- **Severity:** low
- **Lifecycle:** active
- **Last modified:** 2026-04-18
- **Canonical URL:** https://auditbuffet.com/patterns/ab-002159
- **License:** CC-BY-4.0 — attribute to AuditBuffet Pattern Catalog (https://auditbuffet.com/patterns/ab-002159)

## Why it matters

Inconsistent naming conventions in TypeScript code — snake_case variables, Hungarian notation, mixed component casing — increase cognitive load for every developer reading the code and signal that the project lacks enforced standards. ISO 25010:2011 §6.5.2 classifies this as a readability and maintainability defect. In practice, mixed conventions also correlate with inconsistent module structure, inconsistent error handling, and higher defect rates: they are a proxy signal for how rigorously the codebase enforces its own standards.

## Severity rationale

Low because naming inconsistencies do not cause runtime failures but reliably increase cognitive load, make code review harder, and correlate with weaker overall standards enforcement.

## Remediation

Define a convention and enforce it with ESLint's `@typescript-eslint/naming-convention` rule so violations are caught automatically:

```json
{
  "rules": {
    "@typescript-eslint/naming-convention": [
      "error",
      { "selector": "variable", "format": ["camelCase", "UPPER_CASE"] },
      { "selector": "function", "format": ["camelCase", "PascalCase"] },
      { "selector": "typeLike", "format": ["PascalCase"] },
      { "selector": "interface", "format": ["PascalCase"] }
    ]
  }
}
```

For existing violations, use `eslint --fix` for auto-fixable cases. Snake_case variables in TypeScript code (`user_id`, `is_valid`) are the most common — run a search-replace pass on the highest-traffic files first.

## Detection

- **ID:** `naming-conventions`
- **Severity:** `low`
- **What to look for:** Sample 20-30 files from `src/`, `app/`, and `lib/`. Check: variable and function names are camelCase (`getUserById`, `isAuthenticated`, `maxRetries`); class names and React components are PascalCase (`UserService`, `AuthButton`, `DashboardPage`); type and interface names are PascalCase (`UserProfile`, `ApiResponse`); constants are either camelCase or UPPER_SNAKE_CASE — pick one and stick to it. Flag mixed conventions: snake_case variables in TypeScript code (`user_id`, `is_valid`), Hungarian notation (`strUsername`, `bIsActive`), inconsistent component naming (some PascalCase, some kebab-case component files). File naming conventions also matter: Next.js uses kebab-case files, React components may use PascalCase files — check for consistency within the project's own pattern.
- **Pass criteria:** Enumerate all relevant code locations. Consistent naming convention throughout the codebase matching standard TypeScript/JavaScript conventions for each identifier type with at least 1 verified location.
- **Fail criteria:** Mixed naming conventions — e.g., snake_case variable names in TypeScript code, inconsistent component casing, Hungarian notation.
- **Skip (N/A) when:** Never — naming conventions apply to all codebases.
- **Detail on fail:** `"Mixed naming conventions: snake_case variable names found in TypeScript source; constants use both camelCase and UPPER_SNAKE_CASE"`
- **Remediation:** Define a convention and apply it with ESLint's `@typescript-eslint/naming-convention` rule:

  ```json
  {
    "rules": {
      "@typescript-eslint/naming-convention": [
        "error",
        { "selector": "variable", "format": ["camelCase", "UPPER_CASE"] },
        { "selector": "function", "format": ["camelCase", "PascalCase"] },
        { "selector": "typeLike", "format": ["PascalCase"] },
        { "selector": "interface", "format": ["PascalCase"] }
      ]
    }
  }
  ```

  Use search/replace to migrate existing violations, or apply `eslint --fix` for auto-fixable cases.

## External references

- iso-25010 maintainability.analysability

Taxons: code-quality

HTML version: https://auditbuffet.com/patterns/ab-002159