fix(webui): show quoted context after follow-up send (#5071)

webui/src/tests/user-message-quote.test.ts

@@ -0,0 +1,36 @@
+import { describe, expect, it } from "vitest";
+
+import {
+  formatQuotedUserMessage,
+  parseQuotedUserMessage,
+} from "@/lib/user-message-quote";
+
+describe("user message quotes", () => {
+  it("round-trips multiline quoted context through the message body", () => {
+    const content = formatQuotedUserMessage(
+      "What does this mean?",
+      "first quoted line\n\nsecond quoted line",
+    );
+
+    expect(content).toBe(
+      "> [!QUOTE]\n> first quoted line\n>\n> second quoted line\n\nWhat does this mean?",
+    );
+    expect(parseQuotedUserMessage(content)).toEqual({
+      quotedContext: "first quoted line\n\nsecond quoted line",
+      content: "What does this mean?",
+    });
+  });
+
+  it("leaves ordinary messages and manual blockquotes unchanged", () => {
+    const manualBlockquote = "> manually typed quote\n\nordinary message";
+
+    expect(parseQuotedUserMessage(manualBlockquote)).toEqual({
+      quotedContext: null,
+      content: manualBlockquote,
+    });
+  });
+
+  it("does not place quoted context ahead of slash commands", () => {
+    expect(formatQuotedUserMessage("/model", "selected answer excerpt")).toBe("/model");
+  });
+});