import { describe, expect, test, vi } from "vitest";
import triggerCompactExtension from "../examples/extensions/trigger-compact.js";
import type { ExtensionAPI, ExtensionCommandContext, ExtensionContext } from "../src/core/extensions/index.js";
function createContext(tokens: number | null, compact = vi.fn()): ExtensionContext {
return {
hasUI: false,
ui: {} as ExtensionContext["ui"],
cwd: process.cwd(),
sessionManager: {} as ExtensionContext["sessionManager"],
modelRegistry: {} as ExtensionContext["modelRegistry"],
model: undefined,
isIdle: () => true,
signal: undefined,
abort: vi.fn(),
hasPendingMessages: () => false,
shutdown: vi.fn(),
getContextUsage: () => ({ tokens, contextWindow: 200_000, percent: tokens === null ? null : tokens / 2000 }),
compact,
getSystemPrompt: () => "",
};
}
describe("trigger-compact example extension", () => {
test("only auto-compacts when context usage crosses the threshold", () => {
let turnEndHandler:
| ((event: { type: "turn_end" }, ctx: ExtensionContext | ExtensionCommandContext) => void)
| undefined;
const api = {
on: (event: string, handler: (event: { type: "turn_end" }, ctx: ExtensionContext) => void) => {
if (event === "turn_end") {
turnEndHandler = handler;
}
},
registerCommand: vi.fn(),
} as unknown as ExtensionAPI;
triggerCompactExtension(api);
expect(turnEndHandler).toBeDefined();
const compact = vi.fn();
const event = { type: "turn_end" } as const;
turnEndHandler?.(event, createContext(110_000, compact));
expect(compact).not.toHaveBeenCalled();
turnEndHandler?.(event, createContext(120_000, compact));
expect(compact).not.toHaveBeenCalled();
turnEndHandler?.(event, createContext(95_000, compact));
expect(compact).not.toHaveBeenCalled();
turnEndHandler?.(event, createContext(105_000, compact));
expect(compact).toHaveBeenCalledTimes(1);
});
});