fix(nitro): skip default logging for expected evlog 4xx errors

.changeset/nitro-skip-default-log-expected-errors.md

@@ -0,0 +1,5 @@
+---
+'evlog': patch
+---
+
+Stop Nitro and Nuxt from printing expected `createError` 4xx responses as `[request error] [unhandled]` in production. The wide event already records these errors, so evlog's Nitro error handler now skips Nitro's default logging for `EvlogError` with a status below 500. Server errors and errors that are not from evlog are still logged by Nitro.

packages/evlog/src/nitro-v3/errorHandler.ts

@@ -5,6 +5,7 @@ import {
   extractErrorStatus,
   buildPlainNitroErrorBody,
   isSensitiveNitroError,
+  isExpectedEvlogError,
   serializeEvlogErrorResponse,
   shouldSerializeNitroErrorAsJson,
   shouldSuppressNitroDevOverlay,
@@ -48,7 +49,7 @@ export default defineErrorHandler(async (error, event, ctx: NitroErrorHandlerCon
 
   const suppressOverlay = shouldSuppressNitroDevOverlay()
 
-  if (!suppressOverlay) {
+  if (!suppressOverlay && !isExpectedEvlogError(evlogError)) {
     await ctx.defaultHandler(error, event, { silent: false })
   }
 

packages/evlog/src/nitro.ts

@@ -115,6 +115,15 @@ export function resolveEvlogError(error: Error): Error | null {
 
 export { extractErrorStatus } from './shared/errors'
 
+/**
+ * Whether an error is an EvlogError with a 4xx status: an expected outcome that
+ * the wide event already records, so Nitro's default logging is skipped for it.
+ * @internal
+ */
+export function isExpectedEvlogError(evlogError: Error | null): boolean {
+  return evlogError !== null && extractErrorStatus(evlogError) < 500
+}
+
 /** Request metadata used to decide JSON vs framework error-page rendering. */
 export interface NitroErrorRequestContext {
   pathname: string

packages/evlog/src/nitro/errorHandler.ts

@@ -8,6 +8,7 @@ import {
   extractErrorStatus,
   buildPlainNitroErrorBody,
   isSensitiveNitroError,
+  isExpectedEvlogError,
   serializeEvlogErrorResponse,
   markH3ErrorHandled,
   shouldSerializeNitroErrorAsJson,
@@ -55,7 +56,7 @@ export default defineNitroErrorHandler(async (error, event, ctx) => {
 
   // Nitro v2 always passes `ctx`, but a missing context (e.g. the handler
   // invoked directly) must degrade to a flushed response, not a crash.
-  if (!suppressOverlay && ctx?.defaultHandler) {
+  if (!suppressOverlay && !isExpectedEvlogError(evlogError) && ctx?.defaultHandler) {
     await ctx.defaultHandler(error, event, { silent: false })
   }
 

packages/evlog/test/nitro-v3/errorHandler.test.ts

@@ -253,6 +253,34 @@ describe('nitro-v3 errorHandler', () => {
       expect(body.message).toBe('Invalid email format')
       expect(body.statusMessage).toBe('Invalid email format')
     })
+
+    it('skips Nitro default logging for an expected 4xx EvlogError in production', async () => {
+      vi.stubEnv('NODE_ENV', 'production')
+
+      const evlogError = Object.assign(new Error('Payment failed'), {
+        name: 'EvlogError',
+        status: 402,
+        data: { why: 'Card declined', fix: 'Use another card' },
+      })
+
+      const response = await invokeErrorHandler(evlogError)
+
+      expect(defaultHandlerMock).not.toHaveBeenCalled()
+      expect(response?.status).toBe(402)
+    })
+
+    it('keeps Nitro default logging for an EvlogError with a 5xx status in production', async () => {
+      vi.stubEnv('NODE_ENV', 'production')
+
+      const evlogError = Object.assign(new Error('Payment provider unavailable'), {
+        name: 'EvlogError',
+        status: 503,
+      })
+
+      await invokeErrorHandler(evlogError)
+
+      expect(defaultHandlerMock).toHaveBeenCalledWith(evlogError, mockEvent, { silent: false })
+    })
   })
 
   describe('HTML page delegation (#390)', () => {

packages/evlog/test/nitro/errorHandler.test.ts

@@ -306,6 +306,34 @@ describe('errorHandler', () => {
       expect(sentBody.message).toBe('Invalid email format')
       expect(sentBody.statusMessage).toBe('Invalid email format')
     })
+
+    it('skips Nitro default logging for an expected 4xx EvlogError in production', async () => {
+      vi.stubEnv('NODE_ENV', 'production')
+
+      const evlogError = Object.assign(new Error('Payment failed'), {
+        name: 'EvlogError',
+        status: 402,
+        data: { why: 'Card declined', fix: 'Use another card' },
+      })
+
+      await invokeErrorHandler(evlogError)
+
+      expect(defaultHandlerMock).not.toHaveBeenCalled()
+      expect(readResponseBody().statusCode).toBe(402)
+    })
+
+    it('keeps Nitro default logging for an EvlogError with a 5xx status in production', async () => {
+      vi.stubEnv('NODE_ENV', 'production')
+
+      const evlogError = Object.assign(new Error('Payment provider unavailable'), {
+        name: 'EvlogError',
+        status: 503,
+      })
+
+      await invokeErrorHandler(evlogError)
+
+      expect(defaultHandlerMock).toHaveBeenCalledWith(evlogError, mockEvent, { silent: false })
+    })
   })
 
   describe('HTML page delegation (#390)', () => {