diff --git a/src/client/src/chatGroups.test.ts b/src/client/src/chatGroups.test.ts
new file mode 100644
index 0000000..bf43384
--- /dev/null
+++ b/src/client/src/chatGroups.test.ts
@@ -0,0 +1,58 @@
+import { describe, expect, it } from "vitest";
+import { groupChatMessages, summarizeChatGroup } from "./chatGroups";
+import type { ChatLine } from "./components/shared";
+
+const text = (role: ChatLine["role"], value: string): ChatLine => ({ role, parts: [{ type: "text", text: value }] });
+
+describe("groupChatMessages", () => {
+  it("groups technical parts until a readable message is encountered", () => {
+    const messages: ChatLine[] = [
+      { role: "assistant", parts: [{ type: "thinking", text: "plan" }, { type: "toolCall", toolName: "read", summary: "file" }] },
+      text("assistant", "visible answer"),
+      { role: "tool", parts: [{ type: "toolResult", toolName: "read", text: "ok", isError: false }] },
+    ];
+
+    expect(groupChatMessages(messages, 10)).toEqual([
+      { kind: "group", startIndex: 10, messages: [messages[0]] },
+      { kind: "message", index: 11, message: text("assistant", "visible answer") },
+      { kind: "group", startIndex: 12, messages: [messages[2]] },
+    ]);
+  });
+
+  it("splits mixed readable and technical parts from a single message", () => {
+    const messages: ChatLine[] = [
+      { role: "assistant", parts: [{ type: "thinking", text: "hidden" }, { type: "text", text: "shown" }] },
+    ];
+
+    expect(groupChatMessages(messages)).toEqual([
+      { kind: "group", startIndex: 0, messages: [{ role: "assistant", parts: [{ type: "thinking", text: "hidden" }] }] },
+      { kind: "message", index: 0, message: { role: "assistant", parts: [{ type: "text", text: "shown" }] } },
+    ]);
+  });
+
+  it("treats compaction and branch summaries as grouped events", () => {
+    const messages: ChatLine[] = [
+      { ...text("assistant", "summary"), source: "compaction" },
+      { ...text("assistant", "branch"), source: "branch_summary" },
+    ];
+
+    const groups = groupChatMessages(messages);
+
+    expect(groups).toHaveLength(1);
+    expect(groups[0]).toMatchObject({ kind: "group", startIndex: 0 });
+  });
+});
+
+describe("summarizeChatGroup", () => {
+  it("summarizes special event groups", () => {
+    expect(summarizeChatGroup([{ ...text("assistant", "a"), source: "compaction" }])).toBe("1 history compaction summary");
+    expect(summarizeChatGroup([
+      { ...text("assistant", "a"), source: "branch_summary" },
+      { ...text("assistant", "b"), source: "branch_summary" },
+    ])).toBe("2 branch summaries");
+  });
+
+  it("summarizes mixed groups by role counts", () => {
+    expect(summarizeChatGroup([text("tool", "a"), text("system", "b"), text("tool", "c")])).toBe("3 events · 2 tool · 1 system");
+  });
+});
diff --git a/src/client/src/inputModes.test.ts b/src/client/src/inputModes.test.ts
new file mode 100644
index 0000000..717da29
--- /dev/null
+++ b/src/client/src/inputModes.test.ts
@@ -0,0 +1,23 @@
+import { describe, expect, it } from "vitest";
+import { inputModeForDraft, isShellInput } from "./inputModes";
+
+describe("inputModeForDraft", () => {
+  it("detects shell input and context-excluded shell input after leading whitespace", () => {
+    expect(inputModeForDraft(" ! npm test")).toEqual({ kind: "shell", excludeFromContext: false });
+    expect(inputModeForDraft("\n!! secret command")).toEqual({ kind: "shell", excludeFromContext: true });
+    expect(isShellInput(" ! pwd")).toBe(true);
+  });
+
+  it("detects slash commands only for the current token", () => {
+    expect(inputModeForDraft("/compact")).toEqual({ kind: "command" });
+    expect(inputModeForDraft("please /compact")).toEqual({ kind: "command" });
+    expect(inputModeForDraft("please mention/path")).toEqual({ kind: "normal" });
+  });
+
+  it("detects file completion contexts", () => {
+    expect(inputModeForDraft("open @src/main.ts")).toEqual({ kind: "file" });
+    expect(inputModeForDraft("open @ ")).toEqual({ kind: "file" });
+    expect(inputModeForDraft("open @ \"src/main.ts")).toEqual({ kind: "file" });
+    expect(inputModeForDraft("open \"src/main.ts")).toEqual({ kind: "normal" });
+  });
+});
diff --git a/src/client/src/route.test.ts b/src/client/src/route.test.ts
new file mode 100644
index 0000000..cb0eb1f
--- /dev/null
+++ b/src/client/src/route.test.ts
@@ -0,0 +1,76 @@
+import { afterEach, describe, expect, it, vi } from "vitest";
+import { readRoute, writeRoute, type AppRoute } from "./route";
+
+const originalWindow = globalThis.window;
+
+afterEach(() => {
+  vi.restoreAllMocks();
+  Object.defineProperty(globalThis, "window", { value: originalWindow, configurable: true });
+});
+
+function installWindow(href: string): { pushed: string[] } {
+  const url = new URL(href);
+  const pushed: string[] = [];
+  const fakeWindow = {
+    location: {
+      href: url.href,
+      pathname: url.pathname,
+      search: url.search,
+      hash: url.hash,
+    },
+    history: {
+      pushState: vi.fn((_state: object, _title: string, next: URL | string) => {
+        pushed.push(String(next));
+      }),
+    },
+  };
+  Object.defineProperty(globalThis, "window", { value: fakeWindow, configurable: true });
+  return { pushed };
+}
+
+describe("route helpers", () => {
+  it("reads only supported route fields from the current URL", () => {
+    installWindow("http://localhost/app?project=p1&workspace=w1&session=s1&tool=git&view=files&file=src%2Fmain.ts&diff=README.md");
+
+    expect(readRoute()).toEqual({
+      projectId: "p1",
+      workspaceId: "w1",
+      sessionId: "s1",
+      tool: "git",
+      view: "files",
+      file: "src/main.ts",
+      diff: "README.md",
+    });
+  });
+
+  it("ignores unsupported tool and view values", () => {
+    installWindow("http://localhost/app?tool=terminal&view=settings");
+
+    expect(readRoute()).toMatchObject({ tool: undefined, view: undefined });
+  });
+
+  it("writes compact URLs and preserves path/hash", () => {
+    const { pushed } = installWindow("http://localhost/app?old=1#section");
+    const route: AppRoute = {
+      projectId: "project/id",
+      workspaceId: "workspace id",
+      sessionId: "",
+      tool: "files",
+      view: "chat",
+      file: "src/main.ts",
+      diff: undefined,
+    };
+
+    writeRoute(route);
+
+    expect(pushed).toEqual(["http://localhost/app?old=1&project=project%2Fid&workspace=workspace+id&tool=files&view=chat&file=src%2Fmain.ts#section"]);
+  });
+
+  it("does not push history when the route is unchanged", () => {
+    const { pushed } = installWindow("http://localhost/app?project=p1&tool=git");
+
+    writeRoute({ projectId: "p1", workspaceId: undefined, sessionId: undefined, tool: "git", view: undefined, file: undefined, diff: undefined });
+
+    expect(pushed).toEqual([]);
+  });
+});