feat: add error formatting tests and interfaces for consistent error handling

frontends/nextjs/src/lib/errors/format-error.test.ts

@@ -0,0 +1,67 @@
+import { describe, it, expect } from 'vitest'
+import { formatError } from './format-error'
+import { DBALError, DBALErrorCode } from '@/dbal/development/src/core/foundation/errors'
+
+describe('formatError', () => {
+  it.each([
+    {
+      error: new DBALError(DBALErrorCode.NOT_FOUND, 'Resource not found'),
+      expected: {
+        message: 'Resource not found',
+        code: 404,
+        details: undefined,
+      },
+      description: 'DBALError without details',
+    },
+    {
+      error: new DBALError(DBALErrorCode.VALIDATION_ERROR, 'Invalid input', {
+        fields: [{ field: 'email', error: 'Invalid format' }],
+      }),
+      expected: {
+        message: 'Invalid input',
+        code: 422,
+        details: { fields: [{ field: 'email', error: 'Invalid format' }] },
+      },
+      description: 'DBALError with details',
+    },
+    {
+      error: new Error('Standard error'),
+      expected: {
+        message: 'Standard error',
+        stack: expect.any(String),
+      },
+      description: 'Standard Error',
+    },
+    {
+      error: 'String error',
+      expected: {
+        message: 'String error',
+      },
+      description: 'String error',
+    },
+    {
+      error: { message: 'Custom error' },
+      expected: {
+        message: 'Custom error',
+      },
+      description: 'Error-like object',
+    },
+    {
+      error: null,
+      expected: {
+        message: 'An unknown error occurred',
+      },
+      description: 'null',
+    },
+    {
+      error: undefined,
+      expected: {
+        message: 'An unknown error occurred',
+      },
+      description: 'undefined',
+    },
+  ])('should format $description correctly', ({ error, expected }) => {
+    const result = formatError(error)
+    expect(result).toMatchObject(expected)
+  })
+})

frontends/nextjs/src/lib/errors/format-error.ts

@@ -1,12 +1,6 @@
-import { DBALError, DBALErrorCode } from '@/dbal/development/src/core/foundation/errors'
+import { DBALError } from '@/dbal/core/foundation/errors'
 import { getErrorMessage, isError } from '@/lib/types/guards'
-
-export interface FormattedError {
-  message: string
-  code?: DBALErrorCode | number
-  stack?: string
-  details?: Record<string, unknown>
-}
+import type { FormattedError } from './interfaces/formatted-error'
 
 /**
  * Format any error into a consistent structure

frontends/nextjs/src/lib/errors/index.ts

@@ -1,6 +1,8 @@
-export { formatError, toUserMessage } from './format-error'
+export { formatError } from './format-error'
 export type { FormattedError } from './format-error'
 
+export { toUserMessage } from './to-user-message'
+
 export { handleAPIError } from './handle-api-error'
 export type { APIErrorResponse } from './handle-api-error'
 

frontends/nextjs/src/lib/errors/interfaces/api-error-response.ts

@@ -0,0 +1,6 @@
+export interface APIErrorResponse {
+  error: string
+  code?: number
+  details?: Record<string, unknown>
+  timestamp?: string
+}

frontends/nextjs/src/lib/errors/interfaces/formatted-error.ts

@@ -0,0 +1,8 @@
+import type { DBALErrorCode } from '@/dbal/development/src/core/foundation/errors'
+
+export interface FormattedError {
+  message: string
+  code?: DBALErrorCode | number
+  stack?: string
+  details?: Record<string, unknown>
+}

frontends/nextjs/src/lib/errors/interfaces/log-context.ts

@@ -0,0 +1,6 @@
+export interface LogContext {
+  component?: string
+  userId?: string
+  action?: string
+  [key: string]: unknown
+}