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

eventsourcingdb/src/main/java/io/thenativeweb/eventsourcingdb/ErrorCode.java

@@ -208,7 +208,7 @@ public final class ErrorCode {
     /** The code {@code restore-in-progress}: a restore is in progress, so the database does not accept the request. */
     public static final String RESTORE_IN_PROGRESS = BASE_URL + "restore-in-progress";
 
-    /** The code {@code store-failed}: the database failed unexpectedly while it handled the request. */
+    /** The code {@code store-failed}: the store has failed before, so it refuses writes until the database is restarted. */
     public static final String STORE_FAILED = BASE_URL + "store-failed";
 
     /** The code {@code indexes-rebuilding}: the database is rebuilding its indexes, so it does not answer the request yet. */

eventsourcingdb/src/main/java/io/thenativeweb/eventsourcingdb/Outcomes.java

@@ -26,18 +26,18 @@ final class Outcomes {
         return (status >= 400 && status < 500) || status == 503 || status == 507;
     };
 
-    // The v2 API refuses a write it accepted with an error in its answer,
-    // except for store-failed, which reports that storing it failed halfway.
-    // It refuses a write it did not accept with a status code: 400 for a body
-    // of the wrong shape, 401 for an invalid API token, 408 for a body that
-    // did not arrive in time, 413 for a body that is too large, 429 for too
-    // many requests, and 503 for a server that is shutting down.
+    // The v2 API refuses a write it accepted with an error in its answer, and
+    // a write it did not accept with a status code: 400 for a body of the
+    // wrong shape, 401 for an invalid API token, 408 for a body that did not
+    // arrive in time, 413 for a body that is too large, 429 for too many
+    // requests, and 503 for a server that is shutting down.
+    // The error store-failed is a refusal, too: the server sends it only for
+    // writes that it refuses before storing them, once its store has failed.
+    // A write during which storing fails gets a 500, or a stream that ends
+    // without its end item, instead.
     static final Predicate<DbApiException> V2_REFUSALS = exception -> {
-        if (exception.status() == 200) {
-            return !exception.code().equals(ErrorCode.STORE_FAILED);
-        }
-
-        return Set.of(400, 401, 408, 413, 429, 503).contains(exception.status());
+        var status = exception.status();
+        return status == 200 || Set.of(400, 401, 408, 413, 429, 503).contains(status);
     };
 
     private Outcomes() {}

eventsourcingdb/src/test/java/io/thenativeweb/eventsourcingdb/OutcomeUnknownExceptionTest.java

@@ -56,6 +56,15 @@ static Stream<Arguments> v2Writes() {
         return Operations.writes().stream().map(Arguments::of);
     }
 
+    // The server sends store-failed only for writes that it refuses before
+    // storing them, once its store has failed, so it is a refusal like any
+    // other error.
+    static Stream<Arguments> v2RefusalsWithAnError() {
+        return Operations.writes().stream()
+                .flatMap(operation -> Stream.of(ErrorCode.PRECONDITION_VIOLATED, ErrorCode.STORE_FAILED)
+                        .map(code -> Arguments.of(operation, code)));
+    }
+
     private static Client clientWith(FakeServer server) {
         return new Client(server.url(), "secret", new ClientOptions().withStallTimeout(STALL_TIMEOUT));
     }
@@ -127,34 +136,21 @@ void reportsAWriteThatTheServerAnswersWithAnotherStatusAsUnknown(ApiVersion api,
     // The v2 API reports the errors of a write that it accepted within the
     // stream that answers it, after heartbeats, if the write takes long.
     @ParameterizedTest
-    @MethodSource("v2Writes")
-    void reportsAWriteThatTheV2ApiRefusesWithAnErrorAsNotStored(Operation operation) {
-        var error = ApiVersion.V2.item(
-                "error",
-                "{\"code\":\"" + ErrorCode.PRECONDITION_VIOLATED + "\",\"description\":\"refused\",\"details\":{}}");
+    @MethodSource("v2RefusalsWithAnError")
+    void reportsAWriteThatTheV2ApiRefusesWithAnErrorAsNotStored(Operation operation, String code) {
+        var error =
+                ApiVersion.V2.item("error", "{\"code\":\"" + code + "\",\"description\":\"refused\",\"details\":{}}");
 
         try (var server = FakeServer.streaming(ApiVersion.V2, Lines.heartbeat(ApiVersion.V2), error)) {
             var exception =
                     assertThrows(DbApiException.class, () -> operation.call().accept(clientWith(server)));
 
             assertEquals(200, exception.status());
-            assertEquals(ErrorCode.PRECONDITION_VIOLATED, exception.code());
+            assertEquals(code, exception.code());
             assertEquals("refused", exception.description());
         }
     }
 
-    // store-failed reports that storing failed halfway, so it may have been
-    // stored nevertheless.
-    @ParameterizedTest
-    @MethodSource("v2Writes")
-    void reportsAWriteThatTheV2ApiFailedToStoreAsUnknown(Operation operation) {
-        try (var server = FakeServer.streaming(ApiVersion.V2, Lines.error(ApiVersion.V2))) {
-            var cause = assertOutcomeUnknown(DbApiException.class, operation, clientWith(server));
-
-            assertEquals(ErrorCode.STORE_FAILED, cause.code());
-        }
-    }
-
     @ParameterizedTest
     @MethodSource("v2Writes")
     void reportsAWriteWhoseAnswerOfTheV2ApiEndsWithoutItsEndItemAsUnknown(Operation operation) {