MongoDB MCP Server

import { describe, expect, it } from "vitest"; import packageJson from "../../package.json" with { type: "json" }; import "./e2eUtils.js"; import { useCliRunner } from "./e2eUtils.js"; describe("CLI entrypoint", () => { const { runServer } = useCliRunner(); it("should handle version request", async () => { const { stdout, stderr } = await runServer({ args: ["--version"], dryRun: false }); expect(stdout).toContain(packageJson.version); expect(stderr).toEqual(""); }); it("should handle help request", async () => { const { stdout, stderr } = await runServer({ args: ["--help"], dryRun: false }); expect(stdout).toContain("For usage information refer to the README.md"); expect(stderr).toEqual(""); }); it("should handle dry run request", async () => { const { stdout } = await runServer({ args: ["--dryRun"] }); expect(stdout).toContain("Configuration:"); expect(stdout).toContain("Enabled tools:"); // We don't do stderr assertions because in our CI, for docker-less env // atlas local tools push message on stderr stream. }); it("should handle complex configuration", async () => { const { stdout } = await runServer({ args: [ "--connectionString", "mongodb://localhost:1000", "--readOnly", "--httpPort", "8080", "--httpHeaders", '{"test": "3"}', ], stripWhitespace: true, }); expect(stdout).toContain('"connectionString":"mongodb://localhost:1000"'); expect(stdout).toContain('"httpPort":8080'); expect(stdout).toContain('"httpHeaders":{"test":"3"}'); expect(stdout).toContain('"readOnly":true'); }); describe("warnings and error messages", () => { const referDocMessage = "- Refer to https://www.mongodb.com/docs/mcp-server/get-started/ for setting up the MCP Server."; describe("Deprecated CLI arguments", () => { const testCases: { readonly cliArg: string; readonly value?: string; readonly warning: string }[] = [ { cliArg: "--connectionString", value: "mongodb://localhost:27017", warning: "Warning: The --connectionString argument is deprecated. Prefer using the MDB_MCP_CONNECTION_STRING environment variable or the first positional argument for the connection string.", }, ] as const; for (const { cliArg, value, warning } of testCases) { describe(`deprecation behaviour of ${cliArg}`, () => { it(`warns the usage of ${cliArg} as it is deprecated`, async () => { const { stderr } = await runServer({ args: [cliArg, ...(value ? [value] : [])] }); expect(stderr).toContain(warning); }); it(`shows the reference message when ${cliArg} was passed`, async () => { const { stderr } = await runServer({ args: [cliArg, ...(value ? [value] : [])] }); expect(stderr).toContain(referDocMessage); }); }); } }); describe("invalid arguments", () => { const invalidArgumentTestCases = [ { description: "should show an error when an argument is not known", args: ["--wakanda", "forever"], expectedError: "Error: Invalid command line argument '--wakanda'.", }, { description: "should show an error when nodb is used", args: ["--nodb"], expectedError: "Error: The --nodb argument is not supported in the MCP Server. Please remove it from your configuration.", }, { description: "should show a suggestion when is a simple typo", args: ["--readonli", ""], expectedError: "Error: Invalid command line argument '--readonli'. Did you mean '--readOnly'?", }, { description: "should show a suggestion when the only change is on the case", args: ["--readonly", ""], expectedError: "Error: Invalid command line argument '--readonly'. Did you mean '--readOnly'?", }, ]; for (const { description, args, expectedError } of invalidArgumentTestCases) { it(description, async () => { try { await runServer({ args }); expect.fail("Expected process to exit with error"); } catch (error: unknown) { const execError = error as { stderr?: string; code?: number }; expect(execError.code).toBe(1); expect(execError.stderr).toContain(expectedError); expect(execError.stderr).toContain(referDocMessage); } }); } }); describe("vector search misconfiguration", () => { it("should warn if vectorSearch is enabled but embeddings provider is not configured", async () => { const { stderr } = await runServer({ args: ["--previewFeatures", "search"] }); expect(stderr).toContain("Vector search is enabled but no embeddings provider is configured"); }); it("should warn if vectorSearch is not enabled but embeddings provider is configured", async () => { const { stderr } = await runServer({ args: ["--voyageApiKey", "1FOO"] }); expect(stderr).toContain( "An embeddings provider is configured but the 'search' preview feature is not enabled" ); }); it("should not warn if vectorSearch is enabled correctly", async () => { const { stderr } = await runServer({ args: ["--voyageApiKey", "1FOO", "--previewFeatures", "search", "--dryRun"], }); expect(stderr).not.toContain("Vector search is enabled but no embeddings provider is configured"); expect(stderr).not.toContain( "An embeddings provider is configured but the 'search' preview feature is not enabled" ); }); }); }); });