Share MCP echo test fixture

Author: RhysSullivan

packages/plugins/mcp/src/sdk/connection-pool.test.ts

@@ -23,32 +23,24 @@
 
 import { describe, expect, it } from "@effect/vitest";
 import { Effect } from "effect";
-import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
 import z from "zod";
 
 import { createExecutor } from "@executor-js/sdk";
 import { makeTestConfig } from "@executor-js/sdk/testing";
 
 import { mcpPlugin } from "./plugin";
-import { serveMcpServer } from "../testing";
+import { makeEchoMcpServer, serveMcpServer } from "../testing";
 
 // ---------------------------------------------------------------------------
 // Test MCP server — counts session connects (each = one cold handshake)
 // ---------------------------------------------------------------------------
 
 function createTestMcpServer() {
-  const server = new McpServer(
-    { name: "pool-test-server", version: "1.0.0" },
-    { capabilities: {} },
-  );
-
-  server.registerTool(
-    "echo",
-    { description: "Echo a value", inputSchema: { value: z.string() } },
-    async ({ value }: { value: string }) => ({
-      content: [{ type: "text" as const, text: value }],
-    }),
-  );
+  const server = makeEchoMcpServer({
+    name: "pool-test-server",
+    toolName: "echo",
+    toolDescription: "Echo a value",
+  });
 
   server.registerTool(
     "echo2",

packages/plugins/mcp/src/sdk/per-user-auth-isolation.test.ts

@@ -1,7 +1,5 @@
 import { describe, expect, it } from "@effect/vitest";
 import { Cause, Effect, Exit, Predicate } from "effect";
-import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
-import z from "zod";
 
 import {
   ConnectionId,
@@ -18,7 +16,7 @@ import {
 import { makeTestConfig, memorySecretsPlugin } from "@executor-js/sdk/testing";
 
 import { mcpPlugin } from "./plugin";
-import { serveMcpServer } from "../testing";
+import { makeEchoMcpServer, serveMcpServer } from "../testing";
 
 const USER_A = ScopeId.make("user-a");
 const USER_B = ScopeId.make("user-b");
@@ -32,20 +30,14 @@ const failureError = <E>(exit: Exit.Exit<unknown, E>): E | undefined =>
 const isToolInvocationError = (error: unknown): error is ToolInvocationError =>
   Predicate.isTagged(error, "ToolInvocationError");
 
-const createAuthRecordingMcpServer = () => {
-  const mcpServer = new McpServer({ name: "iso-test", version: "1.0.0" }, { capabilities: {} });
-  mcpServer.registerTool(
-    "whoami",
-    {
-      description: "Echoes a marker so the test can prove the invoke reached the server",
-      inputSchema: { marker: z.string() },
-    },
-    async ({ marker }: { marker: string }) => ({
-      content: [{ type: "text" as const, text: `ok:${marker}` }],
-    }),
-  );
-  return mcpServer;
-};
+const createAuthRecordingMcpServer = () =>
+  makeEchoMcpServer({
+    name: "iso-test",
+    toolName: "whoami",
+    toolDescription: "Echoes a marker so the test can prove the invoke reached the server",
+    inputName: "marker",
+    text: (marker) => `ok:${marker}`,
+  });
 
 const serveAuthRecordingMcpServer = serveMcpServer(createAuthRecordingMcpServer);
 

packages/plugins/mcp/src/sdk/testing-fixtures.test.ts

@@ -2,31 +2,18 @@ import { expect, layer } from "@effect/vitest";
 import { Effect } from "effect";
 import { Client } from "@modelcontextprotocol/sdk/client/index.js";
 import { StreamableHTTPClientTransport } from "@modelcontextprotocol/sdk/client/streamableHttp.js";
-import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
 import { OAuthTestServer } from "@executor-js/sdk/testing";
-import z from "zod";
 
-import { serveMcpServerWithOAuth } from "../testing";
+import { makeEchoMcpServer, serveMcpServerWithOAuth } from "../testing";
 
-const createGreetingMcpServer = () => {
-  const server = new McpServer(
-    { name: "executor-test-mcp", version: "1.0.0" },
-    { capabilities: {} },
-  );
-
-  server.registerTool(
-    "hello",
-    {
-      description: "Greets a person",
-      inputSchema: { name: z.string() },
-    },
-    async ({ name }: { readonly name: string }) => ({
-      content: [{ type: "text" as const, text: `Hello ${name}` }],
-    }),
-  );
-
-  return server;
-};
+const createGreetingMcpServer = () =>
+  makeEchoMcpServer({
+    name: "executor-test-mcp",
+    toolName: "hello",
+    toolDescription: "Greets a person",
+    inputName: "name",
+    text: (name) => `Hello ${name}`,
+  });
 
 const makeClient = (endpoint: string, accessToken: string) => {
   const client = new Client({ name: "executor-test-client", version: "1.0.0" });

packages/plugins/mcp/src/testing/index.ts

@@ -1,6 +1,7 @@
 export {
   McpTestServerError,
   McpTestServerLayer,
+  makeEchoMcpServer,
   makeGreetingMcpServer,
   serveMcpServer,
   serveMcpServerWithOAuth,

packages/plugins/mcp/src/testing/server.ts

@@ -3,6 +3,7 @@ import * as http from "node:http";
 import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
 import { StreamableHTTPServerTransport } from "@modelcontextprotocol/sdk/server/streamableHttp.js";
 import { OAuthTestServer } from "@executor-js/sdk/testing";
+import z from "zod";
 
 export type McpTestServer = {
   readonly url: string;
@@ -287,3 +288,41 @@ export const makeGreetingMcpServer = (
 
   return server;
 };
+
+export const makeEchoMcpServer = (
+  options: {
+    readonly name?: string;
+    readonly version?: string;
+    readonly toolName?: string;
+    readonly toolDescription?: string;
+    readonly inputName?: "name" | "value" | "marker";
+    readonly text?: (value: string) => string;
+  } = {},
+) => {
+  const inputName = options.inputName ?? "value";
+  const server = new McpServer(
+    {
+      name: options.name ?? "executor-echo-mcp",
+      version: options.version ?? "1.0.0",
+    },
+    { capabilities: {} },
+  );
+
+  server.registerTool(
+    options.toolName ?? "echo",
+    {
+      description: options.toolDescription ?? "Echoes a string value",
+      inputSchema: { [inputName]: z.string() },
+    },
+    async (input) => ({
+      content: [
+        {
+          type: "text" as const,
+          text: options.text ? options.text(input[inputName]) : input[inputName],
+        },
+      ],
+    }),
+  );
+
+  return server;
+};