Commit LLM generated test cases

frontend/deterministic-tests/src/tests/rapid-updates-after-merge.test.ts

@@ -0,0 +1,74 @@
+import type { ClientState, TestDefinition } from "../test-definition";
+import { assert } from "../utils/assert";
+
+function verifyFinalState(state: ClientState): void {
+    assert(
+        state.files.size === 1,
+        `Expected 1 file, got ${state.files.size}`
+    );
+    assert(
+        state.files.has("doc.md"),
+        `Expected doc.md to exist`
+    );
+    const content = state.files.get("doc.md") ?? "";
+
+    // After the merge and three rapid updates, "update 3" should be present.
+    // Earlier updates may be coalesced, but the final state must include the
+    // last update's content.
+    assert(
+        content.includes("update 3"),
+        `Expected final content to include "update 3", got: "${content}"`
+    );
+}
+
+export const rapidUpdatesAfterMergeTest: TestDefinition = {
+    name: "Rapid Sequential Updates After Concurrent Merge",
+    description:
+        "Both clients create the same file (triggering a merge). After merge " +
+        "completes, Client 0 rapidly sends three updates in succession. Each " +
+        "update must correctly use the content cache to compute diffs against " +
+        "the right parent version. Tests that the cache stores server content " +
+        "(not local content) after MergingUpdate.",
+    clients: 2,
+    steps: [
+        // Both create at same path (triggers merge)
+        { type: "create", client: 0, path: "doc.md", content: "from client 0" },
+        { type: "create", client: 1, path: "doc.md", content: "from client 1" },
+
+        { type: "enable-sync", client: 0 },
+        { type: "enable-sync", client: 1 },
+        { type: "sync" },
+        { type: "barrier" },
+
+        // After merge, Client 0 sends rapid sequential updates
+        {
+            type: "update",
+            client: 0,
+            path: "doc.md",
+            content: "update 1"
+        },
+        { type: "sync", client: 0 },
+
+        {
+            type: "update",
+            client: 0,
+            path: "doc.md",
+            content: "update 2"
+        },
+        { type: "sync", client: 0 },
+
+        {
+            type: "update",
+            client: 0,
+            path: "doc.md",
+            content: "update 3"
+        },
+        { type: "sync", client: 0 },
+
+        // Wait for propagation
+        { type: "barrier" },
+
+        // Both clients must converge with update 3
+        { type: "assert-consistent", verify: verifyFinalState }
+    ]
+};