fix(frontend): use CodedError everywhere

frontend/app/components/app-link.tsx

@@ -4,6 +4,8 @@ import { forwardRef } from 'react';
 import type { Params, Path } from 'react-router';
 import { generatePath, Link } from 'react-router';
 
+import { CodedError } from '~/errors/coded-error';
+import { ErrorCodes } from '~/errors/error-codes';
 import { useLanguage } from '~/hooks/use-language';
 import type { I18nRouteFile } from '~/i18n-routes';
 import { i18nRoutes } from '~/i18n-routes';
@@ -27,8 +29,9 @@ export const AppLink = forwardRef<ElementRef<typeof Link>, AppLinkProps>(
     const targetLanguage = lang ?? currentLanguage;
 
     if (targetLanguage === undefined) {
-      throw new Error(
+      throw new CodedError(
         'The `lang` parameter was not provided, and the current language could not be determined from the request',
+        ErrorCodes.MISSING_LANG_PARAM,
       );
     }
 

frontend/app/errors/coded-error.ts

@@ -1,3 +1,5 @@
+import type { ErrorCode } from '~/errors/error-codes';
+import { ErrorCodes } from '~/errors/error-codes';
 import { randomString } from '~/utils/string-utils';
 
 export type CodedErrorProps = {
@@ -13,7 +15,7 @@ export type CodedErrorProps = {
 export class CodedError {
   public readonly name = 'CodedError';
 
-  public readonly code: string;
+  public readonly code: ErrorCode;
   public readonly correlationId: string;
   public readonly stack?: string;
 
@@ -23,7 +25,7 @@ export class CodedError {
   // message is supplied to `log.error(message, error)`
   public readonly msg?: string;
 
-  public constructor(msg?: string, code = 'UNC-0000', correlationId = generateCorrelationId()) {
+  public constructor(msg?: string, code: ErrorCode = ErrorCodes.UNCAUGHT_ERROR, correlationId = generateCorrelationId()) {
     this.code = code;
     this.correlationId = correlationId;
     this.msg = msg;

frontend/app/errors/error-codes.ts

@@ -0,0 +1,23 @@
+export type ErrorCode = (typeof ErrorCodes)[keyof typeof ErrorCodes];
+
+export const ErrorCodes = {
+  UNCAUGHT_ERROR: 'UNC-0000',
+
+  // auth error codes
+  MISCONFIGURED_PROVIDER: 'AUTH-0001',
+
+  // component error codes
+  MISSING_LANG_PARAM: 'CMP-0001',
+
+  // i18n error codes
+  NO_LANGUAGE_FOUND: 'I18N-0001',
+
+  // route error codes
+  ROUTE_NOT_FOUND: 'RTE-0001',
+
+  // validation error codes
+  INVALID_NUMBER: 'VAL-0001',
+
+  // dev-only error codes
+  TEST_ERROR_CODE: 'DEV-0001',
+} as const;

frontend/app/i18n-config.server.ts

@@ -4,6 +4,8 @@ import { initReactI18next } from 'react-i18next';
 
 import { serverEnvironment } from '~/.server/environment';
 import { i18nResources } from '~/.server/locales';
+import { CodedError } from '~/errors/coded-error';
+import { ErrorCodes } from '~/errors/error-codes';
 import { getLanguage } from '~/utils/i18n-utils';
 
 /**
@@ -24,7 +26,7 @@ export async function getFixedT<NS extends Namespace>(
     : languageOrRequest;
 
   if (language === undefined) {
-    throw new Error('No language found in request');
+    throw new CodedError('No language found in request', ErrorCodes.NO_LANGUAGE_FOUND);
   }
 
   const i18n = await initI18next(language);

frontend/app/routes/auth/callback.tsx

@@ -5,6 +5,8 @@ import { Redacted } from 'effect';
 
 import type { Route } from './+types/callback';
 import { serverEnvironment } from '~/.server/environment';
+import { CodedError } from '~/errors/coded-error';
+import { ErrorCodes } from '~/errors/error-codes';
 import type { AuthenticationStrategy } from '~/utils/auth/authentication-strategy';
 import { AzureADAuthenticationStrategy } from '~/utils/auth/azuread-authentication-strategy';
 import { LocalAuthenticationStrategy } from '~/utils/auth/local-authentication-strategy';
@@ -32,7 +34,7 @@ export async function loader({ context, params, request }: Route.LoaderArgs) {
       const AZUREAD_CLIENT_SECRET = Redacted.value(serverEnvironment.AZUREAD_CLIENT_SECRET);
 
       if (!AZUREAD_ISSUER_URL || !AZUREAD_CLIENT_ID || !AZUREAD_CLIENT_SECRET) {
-        throw new Error('The Azure OIDC settings are misconfigured');
+        throw new CodedError('The Azure OIDC settings are misconfigured', ErrorCodes.MISCONFIGURED_PROVIDER);
       }
 
       const authStrategy = new AzureADAuthenticationStrategy(

frontend/app/routes/auth/login.tsx

@@ -6,6 +6,8 @@ import { Redacted } from 'effect';
 
 import type { Route } from './+types/login';
 import { serverEnvironment } from '~/.server/environment';
+import { CodedError } from '~/errors/coded-error';
+import { ErrorCodes } from '~/errors/error-codes';
 import type { AuthenticationStrategy } from '~/utils/auth/authentication-strategy';
 import { AzureADAuthenticationStrategy } from '~/utils/auth/azuread-authentication-strategy';
 import { LocalAuthenticationStrategy } from '~/utils/auth/local-authentication-strategy';
@@ -39,7 +41,7 @@ export async function loader({ context, params, request }: Route.LoaderArgs) {
       const AZUREAD_CLIENT_SECRET = Redacted.value(serverEnvironment.AZUREAD_CLIENT_SECRET);
 
       if (!AZUREAD_ISSUER_URL || !AZUREAD_CLIENT_ID || !AZUREAD_CLIENT_SECRET) {
-        throw new Error('The Azure OIDC settings are misconfigured');
+        throw new CodedError('The Azure OIDC settings are misconfigured', ErrorCodes.MISCONFIGURED_PROVIDER);
       }
 
       const authStrategy = new AzureADAuthenticationStrategy(

frontend/app/routes/dev/error.tsx

@@ -1,8 +1,9 @@
 import { CodedError } from '~/errors/coded-error';
+import { ErrorCodes } from '~/errors/error-codes';
 
 /**
  * An error route that can be used to test error boundaries.
  */
 export default function Error() {
-  throw new CodedError('ERR-0001');
+  throw new CodedError('This is a test error', ErrorCodes.TEST_ERROR_CODE);
 }

frontend/app/utils/route-utils.ts

@@ -1,3 +1,5 @@
+import { CodedError } from '~/errors/coded-error';
+import { ErrorCodes } from '~/errors/error-codes';
 import type { I18nPageRoute, I18nRoute, I18nRouteFile } from '~/i18n-routes';
 import { isI18nLayoutRoute, isI18nPageRoute } from '~/i18n-routes';
 
@@ -59,7 +61,7 @@ export function getRouteByFile(i18nRouteFile: I18nRouteFile, routes: I18nRoute[]
   const route = findRouteByFile(i18nRouteFile, routes);
 
   if (route === undefined) {
-    throw new Error(`No route found for ${i18nRouteFile} (this should never happen)`);
+    throw new CodedError(`No route found for ${i18nRouteFile} (this should never happen)`, ErrorCodes.ROUTE_NOT_FOUND);
   }
 
   return route;
@@ -77,7 +79,7 @@ export function getRouteByPath(pathname: string, routes: I18nRoute[]): I18nPageR
   const route = findRouteByPath(pathname, routes);
 
   if (route === undefined) {
-    throw new Error(`No route found for ${pathname} (this should never happen)`);
+    throw new CodedError(`No route found for ${pathname} (this should never happen)`, ErrorCodes.ROUTE_NOT_FOUND);
   }
 
   return route;

frontend/app/utils/validation-utils.ts

@@ -1,6 +1,9 @@
 import { Redacted } from 'effect';
 import type { z, ZodEffects, ZodTypeAny } from 'zod';
 
+import { CodedError } from '~/errors/coded-error';
+import { ErrorCodes } from '~/errors/error-codes';
+
 /**
  * Parses a string to a boolean.
  */
@@ -16,7 +19,7 @@ export function asNumber<T extends ZodTypeAny>(schema: T): ZodEffects<T, number>
     const number = Number(val);
 
     if (Number.isNaN(number)) {
-      throw new Error(`Invalid number ${val}`);
+      throw new CodedError(`Invalid number ${val}`, ErrorCodes.INVALID_NUMBER);
     }
 
     return number;

frontend/tests/components/app-link.test.tsx

@@ -4,6 +4,7 @@ import { render } from '@testing-library/react';
 import { beforeEach, describe, expect, it, vi } from 'vitest';
 
 import { AppLink } from '~/components/app-link';
+import type { CodedError } from '~/errors/coded-error';
 
 describe('AppLink', () => {
   beforeEach(() => {
@@ -45,7 +46,7 @@ describe('AppLink', () => {
       {
         path: '/',
         Component: () => <AppLink file="routes/public/index.tsx">This is a test</AppLink>,
-        ErrorBoundary: () => <>{(useRouteError() as Error).message}</>,
+        ErrorBoundary: () => <>{(useRouteError() as CodedError).msg}</>,
       },
     ]);
 

frontend/tests/utils/route-utils.test.ts

@@ -1,5 +1,7 @@
 import { describe, expect, it } from 'vitest';
 
+import { CodedError } from '~/errors/coded-error';
+import { ErrorCodes } from '~/errors/error-codes';
 import type { I18nRouteFile } from '~/i18n-routes';
 import { i18nRoutes, isI18nLayoutRoute, isI18nPageRoute } from '~/i18n-routes';
 import { findRouteByFile, findRouteByPath, getRouteByFile, getRouteByPath } from '~/utils/route-utils';
@@ -43,9 +45,15 @@ describe('route-utils', () => {
     });
 
     it('should throw an error if the route is not found', () => {
-      expect(() => getRouteByFile('routes/💩.tsx' as I18nRouteFile, i18nRoutes)).toThrowError(
-        'No route found for routes/💩.tsx (this should never happen)',
-      );
+      try {
+        getRouteByFile('routes/💩.tsx' as I18nRouteFile, i18nRoutes);
+      } catch (error) {
+        expect(error).toBeInstanceOf(CodedError);
+
+        const codedError = error as CodedError;
+        expect(codedError.msg).toEqual('No route found for routes/💩.tsx (this should never happen)');
+        expect(codedError.code).toEqual(ErrorCodes.ROUTE_NOT_FOUND);
+      }
     });
   });
 
@@ -59,9 +67,15 @@ describe('route-utils', () => {
     });
 
     it('should throw an error if the route is not found', () => {
-      expect(() => getRouteByPath('/en/foobar', i18nRoutes)).toThrowError(
-        'No route found for /en/foobar (this should never happen)',
-      );
+      try {
+        getRouteByPath('/en/foobar', i18nRoutes);
+      } catch (error) {
+        expect(error).toBeInstanceOf(CodedError);
+
+        const codedError = error as CodedError;
+        expect(codedError.msg).toEqual('No route found for /en/foobar (this should never happen)');
+        expect(codedError.code).toEqual(ErrorCodes.ROUTE_NOT_FOUND);
+      }
     });
   });