Commit LLM generated test cases

frontend/deterministic-tests/src/tests/mc-delete-then-offline-rename.test.ts

@@ -0,0 +1,98 @@
+import type { ClientState, TestDefinition } from "../test-definition";
+import { assert } from "../utils/assert";
+
+/**
+ * Edge case: Client 0 creates a file, syncs. Client 1 receives it. Then Client
+ * 0 deletes the file and syncs. Meanwhile Client 1 goes offline and renames it.
+ *
+ * Timeline:
+ *   1. Client 0 creates A.md, both sync.
+ *   2. Client 1 goes offline.
+ *   3. Client 0 deletes A.md, syncs (server marks document as deleted).
+ *   4. Client 1 (offline) renames A.md -> B.md.
+ *   5. Client 1 reconnects.
+ *
+ * The tricky part: Client 1's rename targets a document that was deleted on the
+ * server between Client 1's disconnect and reconnect. The offline rename is a
+ * sync-update with oldPath=A.md, relativePath=B.md. On reconnect, the offline
+ * reconciliation detects B.md as a local file with a documentId pointing to a
+ * deleted server document. The system must decide: honor the rename (creating a
+ * new document at B.md) or propagate the delete.
+ *
+ * This test verifies that both clients converge regardless of which resolution
+ * strategy the system uses, and that no data is silently lost without the other
+ * client also seeing the same result.
+ *
+ * We also add a second file C.md that remains untouched to verify unrelated
+ * documents are not affected by the conflict resolution.
+ */
+
+function verifyState(state: ClientState): void {
+    // C.md must always survive (unrelated to the conflict)
+    assert(
+        state.files.has("C.md"),
+        `Expected C.md to exist (untouched). ` +
+            `Files: ${Array.from(state.files.keys()).join(", ")}`
+    );
+    assert(
+        state.files.get("C.md") === "unrelated",
+        `Expected C.md content to be "unrelated", got: "${state.files.get("C.md")}"`
+    );
+
+    // A.md should NOT exist (it was either renamed or deleted)
+    assert(
+        !state.files.has("A.md"),
+        `Expected A.md to NOT exist. ` +
+            `Files: ${Array.from(state.files.keys()).join(", ")}`
+    );
+
+    // Either B.md exists (rename won) or no extra files exist (delete won).
+    // The key invariant is convergence, which assert-consistent already checks.
+    // But let's also verify that the content is correct if B.md exists.
+    if (state.files.has("B.md")) {
+        const content = state.files.get("B.md") ?? "";
+        assert(
+            content === "original",
+            `If B.md exists (rename won), it should have the original content. Got: "${content}"`
+        );
+    }
+}
+
+export const mcDeleteThenOfflineRenameTest: TestDefinition = {
+    name: "MC: Delete Synced Then Offline Rename",
+    description:
+        "Client 0 creates A.md, both sync. Client 1 goes offline. Client 0 deletes " +
+        "A.md and syncs. Client 1 (offline) renames A.md to B.md. Client 1 reconnects. " +
+        "Both must converge. C.md (unrelated) must be unaffected.",
+    clients: 2,
+    steps: [
+        // Phase 1: Client 0 creates A.md and C.md, both sync
+        { type: "create", client: 0, path: "A.md", content: "original" },
+        { type: "create", client: 0, path: "C.md", content: "unrelated" },
+        { type: "enable-sync", client: 0 },
+        { type: "enable-sync", client: 1 },
+        { type: "sync" },
+        { type: "barrier" },
+        { type: "assert-content", client: 1, path: "A.md", content: "original" },
+        { type: "assert-content", client: 1, path: "C.md", content: "unrelated" },
+
+        // Phase 2: Client 1 goes offline
+        { type: "disable-sync", client: 1 },
+
+        // Phase 3: Client 0 deletes A.md and syncs
+        { type: "delete", client: 0, path: "A.md" },
+        { type: "sync", client: 0 },
+        { type: "assert-not-exists", client: 0, path: "A.md" },
+
+        // Phase 4: Client 1 (offline) renames A.md -> B.md
+        { type: "rename", client: 1, oldPath: "A.md", newPath: "B.md" },
+
+        // Phase 5: Client 1 reconnects
+        { type: "enable-sync", client: 1 },
+        { type: "sync" },
+        { type: "barrier" },
+
+        // Both must converge — key assertions
+        { type: "assert-consistent", verify: verifyState }
+    ]
+};