feat: add bash pty diagnostics

src/agents/bash-tools.pty.test.ts

@@ -0,0 +1,65 @@
+import { describe, expect, it, vi } from "vitest";
+
+describe("bash tool pty mode", () => {
+  it("falls back to pipe with warning when node-pty fails to load", async () => {
+    vi.resetModules();
+    vi.doMock("node-pty", () => {
+      throw new Error("boom");
+    });
+
+    const { createBashTool } = await import("./bash-tools.js");
+    const tool = createBashTool({ backgroundMs: 10, timeoutSec: 1 });
+    const result = await tool.execute("call", {
+      command: "echo test",
+      stdinMode: "pty",
+    });
+
+    const text = result.content.find((c) => c.type === "text")?.text ?? "";
+    expect(text).toContain("Warning: node-pty failed to load");
+    expect(text).toContain("falling back to pipe mode.");
+
+    vi.doUnmock("node-pty");
+  });
+
+  it("uses node-pty when available", async () => {
+    vi.resetModules();
+    const spawn = vi.fn(() => {
+      let onData: ((data: string) => void) | undefined;
+      let onExit:
+        | ((event: { exitCode: number | null; signal?: number | null }) => void)
+        | undefined;
+      const pty = {
+        pid: 4321,
+        onData: (cb: (data: string) => void) => {
+          onData = cb;
+        },
+        onExit: (
+          cb: (event: { exitCode: number | null; signal?: number | null }) => void,
+        ) => {
+          onExit = cb;
+        },
+        write: vi.fn(),
+        kill: vi.fn(),
+      };
+      setTimeout(() => {
+        onData?.("hello\n");
+        onExit?.({ exitCode: 0, signal: null });
+      }, 10);
+      return pty;
+    });
+    vi.doMock("node-pty", () => ({ spawn }));
+
+    const { createBashTool } = await import("./bash-tools.js");
+    const tool = createBashTool({ backgroundMs: 10, timeoutSec: 1 });
+    const result = await tool.execute("call", {
+      command: "ignored",
+      stdinMode: "pty",
+    });
+
+    const text = result.content.find((c) => c.type === "text")?.text ?? "";
+    expect(text).toContain("hello");
+    expect(text).not.toContain("Warning:");
+
+    vi.doUnmock("node-pty");
+  });
+});