fix: preserve reconciliation authorities

tests/unit/optimistic-layer-runtime.test.ts

@@ -25,6 +25,82 @@ function scope() {
 }
 
 describe("revision-safe optimistic layer runtime", () => {
+  it.each(["ROLLBACK", "RECONCILE"] as const)(
+    "rejects a composite-invalid candidate without losing prior %s authority",
+    (authority) => {
+      const client = new QueryClient();
+      const key = ["query", "composite-candidate", authority];
+      client.setQueryData(key, ["base"]);
+      const selectedScope = scope();
+      const runtime = createOptimisticLayerRuntime(client);
+      const first = runtime.begin(
+        key,
+        "first",
+        (previous, input) => [...(previous as string[]), input],
+        selectedScope.snapshot,
+      );
+      if (authority === "RECONCILE") first?.markUncertain();
+
+      const second = runtime.begin(
+        key,
+        "second",
+        (previous, input) => {
+          const values = previous as string[];
+          if (values.includes("first")) {
+            throw new Error("candidate composes only over the base");
+          }
+          return [...values, input];
+        },
+        selectedScope.snapshot,
+      );
+
+      expect(second).toBeNull();
+      expect(client.getQueryData(key)).toEqual(["base", "first"]);
+      if (authority === "ROLLBACK") {
+        first?.rollback();
+      } else {
+        first?.reconcile("NOT_APPLIED");
+      }
+      expect(client.getQueryData(key)).toEqual(["base"]);
+    },
+  );
+
+  it("writes a prevalidated candidate without invoking its updater twice", () => {
+    const client = new QueryClient();
+    const key = ["query", "single-candidate-invocation"];
+    client.setQueryData(key, ["base"]);
+    const selectedScope = scope();
+    const runtime = createOptimisticLayerRuntime(client);
+    const first = runtime.begin(
+      key,
+      "first",
+      (previous, input) => [...(previous as string[]), input],
+      selectedScope.snapshot,
+    );
+    let candidateCalls = 0;
+
+    const second = runtime.begin(
+      key,
+      "second",
+      (previous, input) => {
+        candidateCalls += 1;
+        if (candidateCalls > 1) {
+          throw new Error("candidate updater must not be replayed on admission");
+        }
+        return [...(previous as string[]), input];
+      },
+      selectedScope.snapshot,
+    );
+
+    expect(second).not.toBeNull();
+    expect(candidateCalls).toBe(1);
+    expect(client.getQueryData(key)).toEqual(["base", "first", "second"]);
+    second?.rollback();
+    expect(client.getQueryData(key)).toEqual(["base", "first"]);
+    first?.rollback();
+    expect(client.getQueryData(key)).toEqual(["base"]);
+  });
+
   it("removes only the failed layer when commands settle out of order", () => {
     const client = new QueryClient();
     const key = ["query", "resources"];