test(codex-lsp): cover lazy metadata fallback

2026-05-29 13:18:46 +09:00
parent 8896db9806
commit 26ec219bcd
1 changed files with 82 additions and 1 deletions
@@ -1,5 +1,6 @@
+import { PassThrough } from "node:stream";
 import { describe, expect, it } from "vitest";
-import { resolveLazyLspIdleTimeoutMs } from "../src/lazy-lsp-mcp.js";
+import { resolveLazyLspIdleTimeoutMs, runLazyLspMcpServer } from "../src/lazy-lsp-mcp.js";
 import { DEFAULT_LAZY_MCP_IDLE_TIMEOUT_MS } from "../src/lazy-mcp-proxy.js";

 describe("lazy LSP MCP config", () => {
@@ -18,4 +19,84 @@ describe("lazy LSP MCP config", () => {
 		expect(malformed.value).toBe(fallback);
 		expect(malformed.warning).toContain("Ignoring malformed lazy MCP idle timeout");
 	});
+
+	it("#given missing lazy backend config #when metadata requests are served #then the server stays usable without starting a backend", async () => {
+		// given
+		const input = new PassThrough();
+		const output = new PassThrough();
+		const chunks: string[] = [];
+		const previousBackendConfig = process.env["CODEX_LSP_LAZY_BACKEND"];
+		delete process.env["CODEX_LSP_LAZY_BACKEND"];
+		output.on("data", (chunk: Buffer | string) => {
+			chunks.push(chunk.toString());
+		});
+
+		try {
+			const server = runLazyLspMcpServer(input, output);
+
+			// when
+			input.write(
+				`${JSON.stringify({
+					jsonrpc: "2.0",
+					id: 1,
+					method: "initialize",
+					params: { protocolVersion: "2024-11-05", capabilities: {}, clientInfo: { name: "test" } },
+				})}\n`,
+			);
+			input.write(`${JSON.stringify({ jsonrpc: "2.0", id: 2, method: "tools/list", params: {} })}\n`);
+			input.end();
+			await server;
+		} finally {
+			restoreEnv("CODEX_LSP_LAZY_BACKEND", previousBackendConfig);
+		}
+
+		// then
+		const responses = parseJsonRpcResponses(chunks.join(""));
+		expect(responses).toHaveLength(2);
+		expect(responses[0]?.result?.serverInfo).toEqual({ name: "lsp", version: "0.2.0" });
+		expect(toolNames(responses[1])).toContain("status");
+	});
 });
+
+interface JsonRpcTestResponse {
+	readonly result?: {
+		readonly serverInfo?: unknown;
+		readonly tools?: unknown;
+	};
+}
+
+function parseJsonRpcResponses(output: string): readonly JsonRpcTestResponse[] {
+	return output
+		.trim()
+		.split(/\n+/)
+		.filter((line) => line.length > 0)
+		.map((line) => {
+			const parsed: unknown = JSON.parse(line);
+			return isJsonRpcTestResponse(parsed) ? parsed : {};
+		});
+}
+
+function toolNames(response: JsonRpcTestResponse | undefined): readonly string[] {
+	const tools = response?.result?.tools;
+	if (!Array.isArray(tools)) return [];
+	return tools.flatMap((tool) => {
+		if (!isRecord(tool) || typeof tool["name"] !== "string") return [];
+		return [tool["name"]];
+	});
+}
+
+function restoreEnv(name: string, value: string | undefined): void {
+	if (value === undefined) {
+		delete process.env[name];
+		return;
+	}
+	process.env[name] = value;
+}
+
+function isJsonRpcTestResponse(value: unknown): value is JsonRpcTestResponse {
+	return isRecord(value);
+}
+
+function isRecord(value: unknown): value is Record<string, unknown> {
+	return typeof value === "object" && value !== null && !Array.isArray(value);
+}