fix(functions): await functions error handling (#7186)

Author: serhalp

src/lib/functions/server.ts

@@ -254,7 +254,7 @@ export const createHandler = function (options: GetFunctionsServerOptions): Requ
         return
       }
 
-      handleSynchronousFunction({ error, functionName: func.name, result, request, response })
+      await handleSynchronousFunction({ error, functionName: func.name, result, request, response })
     }
   }
 }

src/lib/functions/synchronous.ts

@@ -25,7 +25,7 @@ const addHeaders = (headers: undefined | Record<string, string | string[]>, resp
   })
 }
 
-export const handleSynchronousFunction = function ({
+export const handleSynchronousFunction = async function ({
   error: invocationError,
   functionName,
   request,
@@ -37,7 +37,7 @@ export const handleSynchronousFunction = function ({
   request: express.Request
   response: express.Response
   result: null | LambdaEvent
-}): void {
+}): Promise<void> {
   if (invocationError) {
     const error = getNormalizedError(invocationError)
 
@@ -47,26 +47,23 @@ export const handleSynchronousFunction = function ({
       }\n${chalk.dim(error.stackTrace.join('\n'))}`,
     )
 
-    // eslint-disable-next-line @typescript-eslint/no-floating-promises -- XXX(serhalp): real bug, fixed in stacked PR.
-    handleErr(invocationError, request, response)
+    await handleErr(invocationError, request, response)
     return
   }
 
   const { error } = validateLambdaResponse(result)
   if (error) {
     logPadded(`${NETLIFYDEVERR} ${error}`)
 
-    // eslint-disable-next-line @typescript-eslint/no-floating-promises -- XXX(serhalp): real bug, fixed in stacked PR.
-    handleErr(error, request, response)
+    await handleErr(error, request, response)
     return
   }
 
   // This shouldn't happen (see `InvokeFunctionResult`), but due to type lossiness TS doesn't know this here.
   if (result == null) {
     logPadded(`${NETLIFYDEVERR} Unexpected empty function response`)
 
-    // eslint-disable-next-line @typescript-eslint/no-floating-promises -- XXX(serhalp): real bug, fixed in stacked PR.
-    handleErr('Unexpected empty function response', request, response)
+    await handleErr('Unexpected empty function response', request, response)
     return
   }
 
@@ -87,8 +84,7 @@ export const handleSynchronousFunction = function ({
       }`,
     )
 
-    // eslint-disable-next-line @typescript-eslint/no-floating-promises -- XXX(serhalp): real bug, fixed in stacked PR.
-    handleErr(wrappedHeadersError, request, response)
+    await handleErr(wrappedHeadersError, request, response)
     return
   }