fix: Count store-failed as a refusal of a write, since the server sends it only for writes that it refuses before storing them.

README.md

@@ -156,7 +156,7 @@ try {
 }
 ```
 
-A write certainly was not stored, and throws the error itself, only if its request never went out, for example since the client SDK refused to send it and threw an `IncompatibleServerError`, or could not establish a connection, or since the write was aborted or stalled while connecting, or if the server refused the write before storing anything. A request counts as gone out once its headers have been sent. Through the v2 API, the server refuses a write with every error that it describes in its answer, except one with the code `ErrorCode.storeFailed`, and with the HTTP status `400`, `401`, `408`, `413`, `429`, or `503`. Through the v1 API, it refuses a write with an HTTP status of `4xx`, `503`, or `507`. A write that the server refuses with the HTTP status `429` may be sent again after `retryAfter` seconds.
+A write certainly was not stored, and throws the error itself, only if its request never went out, for example since the client SDK refused to send it and threw an `IncompatibleServerError`, or could not establish a connection, or since the write was aborted or stalled while connecting, or if the server refused the write before storing anything. A request counts as gone out once its headers have been sent. Through the v2 API, the server refuses a write with every error that it describes in its answer and with the HTTP status `400`, `401`, `408`, `413`, `429`, or `503`. Through the v1 API, it refuses a write with an HTTP status of `4xx`, `503`, or `507`. A write that the server refuses with the HTTP status `429` may be sent again after `retryAfter` seconds.
 
 ### Writing Events
 

src/OutcomeUnknownError.test.ts

@@ -88,6 +88,7 @@ const refusals: Record<ApiVersion, Case[]> = {
 			ErrorCode.preconditionViolated,
 			ErrorCode.eventSchemaAlreadyRegistered,
 			ErrorCode.storeReadOnly,
+			ErrorCode.storeFailed,
 		].map(
 			(code): Case => ({
 				name: `an error item with the code '${code}'`,
@@ -132,15 +133,6 @@ const unknownOutcomes: Record<ApiVersion, Case[]> = {
 				isCause: isDbApiErrorWithStatus(status),
 			}),
 		),
-		{
-			name: `an error item with the code '${ErrorCode.storeFailed}'`,
-			answer: (response: ServerResponse): void => {
-				writeHead(response, 200, ndJson);
-				response.end(`${getErrorItem(ErrorCode.storeFailed)}${lines.v2.end}`);
-			},
-			isCause: (error: unknown): boolean =>
-				error instanceof DbApiError && error.code === ErrorCode.storeFailed,
-		},
 		{
 			name: 'a stream that ends without its end item',
 			answer: (response: ServerResponse): void => {

src/v2/isV2Refusal.ts

@@ -1,17 +1,16 @@
 import type { DbApiError } from '../DbApiError.js';
-import { ErrorCode } from '../ErrorCode.js';
 
 // The statuses with which the v2 API refuses a request before handling it.
 const refusingStatuses = new Set([400, 401, 408, 413, 429, 503]);
 
 // Tells whether the v2 API refused a write before storing anything. It does so
-// with every error item, except for a failed store, and with some statuses.
-const isV2Refusal = (error: DbApiError): boolean => {
-	if (error.status === 200) {
-		return error.code !== ErrorCode.storeFailed;
-	}
-
-	return refusingStatuses.has(error.status);
-};
+// with every error item, which comes at the status 200, and with some statuses.
+// This includes an error item with the code store-failed, which the server
+// sends for every write after its store has failed, since it then refuses
+// writes until it is restarted. The write during which storing fails gets the
+// status 500 or a stream without its end item instead, so its outcome stays
+// unknown.
+const isV2Refusal = (error: DbApiError): boolean =>
+	error.status === 200 || refusingStatuses.has(error.status);
 
 export { isV2Refusal };