1 files changed, 45 insertions, 0 deletions
diff --git a/src/core/chunks/local-echo.test.ts b/src/core/chunks/local-echo.test.ts
new file mode 100644
index 0000000..565017c
--- /dev/null
+++ b/src/core/chunks/local-echo.test.ts
@@ -0,0 +1,45 @@
+import { describe, expect, it } from "vitest";
+import { appendUserMessage, applyHistory, foldEvent, initialState, removeLocalEcho } from "./index";
+
+describe("request-local optimistic echo", () => {
+  it("retains identity through turn-start tags without conflating identical sends", () => {
+    let state = appendUserMessage(initialState(), "same", [{ url: "data:first" }], "r1");
+    state = appendUserMessage(state, "same", [{ url: "data:second" }], "r2");
+    state = foldEvent(state, { type: "turn-start", conversationId: "c1", turnId: "t1" });
+    state = removeLocalEcho(state, "r1");
+    expect(state.provisional.map((p) => p.localRequestId)).toEqual(["r2", "r2"]);
+    expect(state.provisional.map((p) => p.chunk)).toEqual([
+      { type: "text", text: "same" },
+      { type: "image", url: "data:second" },
+    ]);
+    expect(state.generating).toBe(true);
+    expect(removeLocalEcho(state, "r1")).toBe(state);
+  });
+
+  it("a live user-message confirms only its deduplicated text, not every identical local send", () => {
+    let state = appendUserMessage(initialState(), "same", [{ url: "data:first" }], "r1");
+    state = appendUserMessage(state, "same", [{ url: "data:second" }], "r2");
+    state = foldEvent(state, { type: "turn-start", conversationId: "c1", turnId: "t1" });
+    state = foldEvent(state, {
+      type: "user-message",
+      conversationId: "c1",
+      turnId: "t1",
+      text: "same",
+    });
+    state = removeLocalEcho(removeLocalEcho(state, "r1"), "r2");
+    expect(state.provisional).toEqual([
+      { role: "user", turnId: "t1", opening: true, chunk: { type: "text", text: "same" } },
+    ]);
+  });
+
+  it("does not remove committed rows even if their content is identical", () => {
+    let state = appendUserMessage(initialState(), "same", undefined, "r1");
+    state = applyHistory(state, [{ seq: 1, role: "user", chunk: { type: "text", text: "same" } }]);
+    const committed = state.committed;
+    state = removeLocalEcho(state, "r1");
+    expect(state.committed).toBe(committed);
+    expect(state.provisional).toEqual([]);
+    expect(removeLocalEcho(state, "r1")).toBe(state);
+    expect(removeLocalEcho(initialState(), "r1")).toEqual(initialState());
+  });
+});