From 1bcf8309ffb522d09d4fd9dc35f7ee957d134e26 Mon Sep 17 00:00:00 2001
From: Drewry Pope <drewrypope@gmail.com>
Date: Mon, 19 Oct 2026 21:48:07 -0500
Subject: [PATCH 1/2] test(cli): cover ACP follow's stale-attach guard

Add a regression test for the guard in turn.follow (packages/cli/src/acp/turn.ts)
that stops a stale session/load from interrupting the newer attachment's
follower. The test holds load A's MCP registration via the wire fixture's
fetch override, lets load B attach and follow, then releases A and asserts
a later permission ask is still answered by B's follower.

Verified: fails with the guard removed (1 fail, the new test), passes with
it; 10/10 under --rerun-each 10; full ACP suite 116/116; cli typecheck clean.

Closes #125
---
 packages/cli/test/acp/turn.test.ts | 39 ++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/packages/cli/test/acp/turn.test.ts b/packages/cli/test/acp/turn.test.ts
index b53be7d67228..4a5ceecddc15 100644
--- a/packages/cli/test/acp/turn.test.ts
+++ b/packages/cli/test/acp/turn.test.ts
@@ -462,6 +462,45 @@ describe("acp turn events over the wire", () => {
     expect(acp.server.replies).toEqual([{ sessionID: acp.sessionId, requestID: "perm_after_load", decision: "once" }])
   })
 
+  test("a stale load finishing after a newer load does not stop the newer follower", async () => {
+    let releaseMcp: (() => void) | undefined
+    const held = new Promise<void>((resolve) => {
+      releaseMcp = resolve
+    })
+    let mcpHeld = false
+    await using acp = await startWire({
+      // Hold load A's MCP registration so load B attaches and starts following first.
+      fetch: async (request) => {
+        if (request.method !== "PUT" || request.path !== "/api/experimental/mcp/tools" || mcpHeld) return undefined
+        mcpHeld = true
+        await held
+        return undefined
+      },
+      permission: () => ({ outcome: { outcome: "selected", optionId: "once" } }),
+    })
+    await acp.initialize()
+    acp.server.sessions.set("ses_stale", makeSession("ses_stale"))
+
+    const stale = acp.request("session/load", {
+      sessionId: "ses_stale",
+      cwd: "/workspace",
+      mcpServers: [{ name: "tools", command: "bun", args: ["server.ts"], env: [] }],
+    })
+    // The fixture records the request before awaiting the fetch override, so its arrival is observable here.
+    await acp.until(
+      () => acp.server.requests.some((item) => item.method === "PUT" && item.path === "/api/experimental/mcp/tools"),
+      "load A's held MCP registration",
+    )
+    await acp.request("session/load", { sessionId: "ses_stale", cwd: "/workspace", mcpServers: [] })
+    releaseMcp!()
+    await stale
+
+    acp.server.send(permissionAsked("ses_stale", "perm_stale", { action: "read" }))
+    await acp.until(() => acp.server.replies.length === 1, "the permission reply from the newer follower")
+
+    expect(acp.server.replies).toEqual([{ sessionID: "ses_stale", requestID: "perm_stale", decision: "once" }])
+  })
+
   test("does not name a tool call the follower tracked but never sent", async () => {
     await using acp = await startSession({ permission: () => ({ outcome: { outcome: "selected", optionId: "once" } }) })
 

From 0b3373db0661464369666e08fcc6796e28961389 Mon Sep 17 00:00:00 2001
From: Drewry Pope <drewrypope@gmail.com>
Date: Mon, 19 Oct 2026 21:50:19 -0500
Subject: [PATCH 2/2] test(lint): run ast-grep lint rule tests in CI (#153)

---
 .github/workflows/test.yml | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 365cf5c3943b..35dac4fa5e49 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -127,6 +127,13 @@ jobs:
           export PATH="$bin_dir:$PATH"
           rg --version
 
+      - name: Test lint rules
+        # The main ast-grep rules (script/ast-grep/rules) have their own
+        # test suite (test:lint-rules) that nothing ran (#153); the
+        # effect-simplification suite below was already wired up.
+        if: runner.os == 'Linux'
+        run: bun run test:lint-rules
+
       - name: Test Effect simplification rules
         if: runner.os == 'Linux'
         run: bun run test:effect-simplification-rules