Spec #164: A sixth outcome word: not_found splits out of errors

backend/internal/latest/poller_test.go

@@ -1947,9 +1947,9 @@ func TestRunLanePassCarryForwardOnlyWhenGapZero(t *testing.T) {
 	})
 }
 
-// The pass row's five outcome counts are the classification the Series read
+// The pass row's six outcome counts are the classification the Series read
 // already makes — never a second taxonomy (issue #141). Success is derived,
-// never stored: checked minus the four named counts, unreachable excluded
+// never stored: checked minus the five named failures, unreachable excluded
 // because its exit returns before the checked counter increments.
 func TestRunLanePassCountsOutcomes(t *testing.T) {
 	s, _ := newTestStore(t)
@@ -1986,7 +1986,7 @@ func TestRunLanePassCountsOutcomes(t *testing.T) {
 		t.Fatalf("outcome counts = refused %d unreachable %d no_chapter %d unfetchable %d errors %d, want 1 0 1 1 1",
 			pass.Refused, pass.Unreachable, pass.NoChapter, pass.Unfetchable, pass.Errors)
 	}
-	if success := pass.Checked - (pass.Refused + pass.NoChapter + pass.Unfetchable + pass.Errors); success != 1 {
+	if success := pass.Checked - (pass.Refused + pass.NoChapter + pass.Unfetchable + pass.NotFound + pass.Errors); success != 1 {
 		t.Fatalf("derived success = %d, want 1", success)
 	}
 	// The one genuine read went through: the success Series carries the
@@ -2009,6 +2009,36 @@ func TestRunLanePassCountsOutcomes(t *testing.T) {
 	}
 }
 
+// A 4xx other than the 403 refusal means the page is gone — a sixth outcome
+// word (issue #164) — while a 5xx stays errors. Both land in the durable row,
+// so the owner can tell "correct the address" from "the Site is unwell"
+// without opening a log.
+func TestRunLanePassSplitsNotFoundFromErrors(t *testing.T) {
+	s, _ := newTestStore(t)
+	now := time.UnixMilli(5_000_000)
+	seeds := map[string]string{
+		"asura:gone":   "https://asurascans.com/series/gone",
+		"asura:unwell": "https://asurascans.com/series/unwell",
+	}
+	for key, url := range seeds {
+		seedForCheck(t, s, key, url, 0)
+	}
+
+	f := &fakeFetcher{perURL: map[string]fakeResponse{
+		seeds["asura:gone"]:   {status: 404},
+		seeds["asura:unwell"]: {status: 503},
+	}}
+	newTestPoller(t, s, f, now).runLanePass(context.Background(), "asura", false)
+
+	pass := latestPassFor(t, s, "asura")
+	if pass.NotFound != 1 || pass.Errors != 1 {
+		t.Fatalf("not_found=%d errors=%d, want 1 1", pass.NotFound, pass.Errors)
+	}
+	if success := pass.Checked - (pass.Refused + pass.NoChapter + pass.Unfetchable + pass.NotFound + pass.Errors); success != 0 {
+		t.Fatalf("derived success = %d, want 0 (both reads failed)", success)
+	}
+}
+
 // A refusal is the Site's mood and outlives our process: the durable stamp a
 // pass writes is honoured by a freshly constructed poller, which must not
 // re-probe the Site inside its backoff (issue #141).