fix(ai): stop streams getting cut off and keep tool steps across messages

plugins/ai/tests/backend/history.test.ts

@@ -0,0 +1,116 @@
+import { describe, expect, it } from "vitest";
+import { toChatHistory, toStoredMessage } from "../../src/backend/history.js";
+
+const calls = [
+  { id: "c1", name: "list_hosts", arguments: {} },
+  { id: "c2", name: "get_host", arguments: { hostId: 1 } },
+];
+
+describe("toStoredMessage", () => {
+  it("keeps the answered call on a tool row", () => {
+    expect(
+      toStoredMessage({
+        role: "tool",
+        content: "{}",
+        toolCallId: "c1",
+        toolName: "list_hosts",
+      }),
+    ).toEqual({
+      role: "tool",
+      content: "{}",
+      toolCalls: JSON.stringify([{ id: "c1", name: "list_hosts" }]),
+    });
+  });
+
+  it("stores no tool calls for a plain reply", () => {
+    expect(toStoredMessage({ role: "assistant", content: "hi" })).toEqual({
+      role: "assistant",
+      content: "hi",
+      toolCalls: null,
+    });
+  });
+});
+
+describe("toChatHistory", () => {
+  it("round-trips a full run", () => {
+    const rows = [
+      { role: "user", content: "check", toolCalls: null },
+      toStoredMessage({ role: "assistant", content: "", toolCalls: calls }),
+      toStoredMessage({
+        role: "tool",
+        content: '{"hosts":[]}',
+        toolCallId: "c1",
+        toolName: "list_hosts",
+      }),
+      toStoredMessage({
+        role: "tool",
+        content: '{"host":{}}',
+        toolCallId: "c2",
+        toolName: "get_host",
+      }),
+      { role: "assistant", content: "done", toolCalls: null },
+    ];
+
+    expect(toChatHistory(rows)).toEqual([
+      { role: "user", content: "check" },
+      { role: "assistant", content: "", toolCalls: calls },
+      {
+        role: "tool",
+        content: '{"hosts":[]}',
+        toolCallId: "c1",
+        toolName: "list_hosts",
+      },
+      {
+        role: "tool",
+        content: '{"host":{}}',
+        toolCallId: "c2",
+        toolName: "get_host",
+      },
+      { role: "assistant", content: "done" },
+    ]);
+  });
+
+  it("fills in results for calls a cut off run never answered", () => {
+    const rows = [
+      { role: "user", content: "check", toolCalls: null },
+      toStoredMessage({ role: "assistant", content: "", toolCalls: calls }),
+      toStoredMessage({
+        role: "tool",
+        content: "{}",
+        toolCallId: "c1",
+        toolName: "list_hosts",
+      }),
+      { role: "user", content: "continue", toolCalls: null },
+    ];
+
+    const history = toChatHistory(rows);
+    expect(history.map((m) => m.role)).toEqual([
+      "user",
+      "assistant",
+      "tool",
+      "tool",
+      "user",
+    ]);
+    expect(history[3]).toMatchObject({
+      toolCallId: "c2",
+      toolName: "get_host",
+    });
+    expect(JSON.parse(history[3].content).error).toMatch(/interrupted/);
+  });
+
+  it("repairs a legacy row saved with tool calls and no results", () => {
+    const history = toChatHistory([
+      { role: "assistant", content: "", toolCalls: JSON.stringify(calls) },
+    ]);
+    expect(history.filter((m) => m.role === "tool")).toHaveLength(2);
+  });
+
+  it("drops tool rows that answer nothing", () => {
+    expect(
+      toChatHistory([
+        { role: "tool", content: "{}", toolCalls: null },
+        { role: "user", content: "hi", toolCalls: null },
+      ]),
+    ).toEqual([{ role: "user", content: "hi" }]);
+  });
+});