/**
* Server-wiring test: boot the actual MCP stdio server (from source via tsx)
* and drive it with the SDK's own client — initialize handshake, tools/list,
* tools/call — to catch registration/schema regressions that the unit tests
* (which import helpers directly) can't see.
*
* This replaces the old standalone tests/smoke.mjs, which spawned the BUILT
* dist/index.js and was therefore never run in CI (CI doesn't build this
* package before testing). Running from source via tsx means it executes as
* part of the normal `vitest run`.
*
* We deliberately do NOT call start_session — it would open a real browser
* window via open(). The browser bridge is covered by the Playwright e2e suite.
*/
import { mkdtempSync, rmSync, writeFileSync } from "node:fs"
import { tmpdir } from "node:os"
import path from "node:path"
import { fileURLToPath } from "node:url"
import { Client } from "@modelcontextprotocol/sdk/client/index.js"
import { StdioClientTransport } from "@modelcontextprotocol/sdk/client/stdio.js"
import type { CallToolResult } from "@modelcontextprotocol/sdk/types.js"
import { afterAll, beforeAll, describe, expect, it } from "vitest"
const __dirname = path.dirname(fileURLToPath(import.meta.url))
const entry = path.resolve(__dirname, "..", "src", "index.ts")
const tsxBin = path.resolve(
__dirname,
"..",
"node_modules",
".bin",
process.platform === "win32" ? "tsx.cmd" : "tsx",
)
const EXPECTED_TOOLS = [
"start_session",
"create_new_diagram",
"load_diagram",
"edit_diagram",
"get_diagram",
"export_diagram",
"list_pages",
"add_page",
"rename_page",
"delete_page",
"get_drawing_guide",
"get_shape_library",
"screenshot_diagram",
"list_saved_diagrams",
"restore_version",
]
// Auto-save folder of the spawned server, holding one saved session
const dataDir = mkdtempSync(path.join(tmpdir(), "mcp-wiring-"))
const SAVED_ID = "mcp-aaaaaaaa-bbb"
const SAVED_DIAGRAM = ``
// Claude Code truncates tool descriptions and server instructions here
const MAX_DESCRIPTION = 2048
// The server reads /instructions.md into the guide; a
// developer's real ~/.next-ai-drawio/instructions.md must not leak in
const CUSTOM_RULE = "Always use blue fill #dae8fc."
let client: Client
const listTools = async () => (await client.listTools()).tools
const findTool = async (name: string) =>
(await listTools()).find((t) => t.name === name)
const properties = async (name: string) =>
(await findTool(name))?.inputSchema?.properties ?? {}
/** A tool call's result; the SDK throws on a JSON-RPC error */
const callTool = async (name: string, args: Record) =>
(await client.callTool({ name, arguments: args })) as CallToolResult
const textOf = (result: CallToolResult) =>
(result.content[0] as { text: string }).text
beforeAll(async () => {
writeFileSync(path.join(dataDir, "instructions.md"), CUSTOM_RULE)
writeFileSync(path.join(dataDir, `${SAVED_ID}.drawio`), SAVED_DIAGRAM)
client = new Client({ name: "wiring-test", version: "0.0.0" })
await client.connect(
new StdioClientTransport({
command: tsxBin,
args: [entry],
env: { ...process.env, DRAWIO_DATA_DIR: dataDir } as Record<
string,
string
>,
// The server's log lines
stderr: "ignore",
}),
)
expect(client.getServerVersion()?.name).toBeTruthy()
}, 30000)
afterAll(async () => {
await client?.close()
rmSync(dataDir, { recursive: true, force: true })
})
describe("MCP server wiring", () => {
it("registers all tools", async () => {
const names = (await listTools()).map((t) => t.name)
for (const expected of EXPECTED_TOOLS) {
expect(names, `missing tool: ${expected}`).toContain(expected)
}
})
it("advertises page-selector params on edit_diagram", async () => {
const props = await properties("edit_diagram")
expect(props.page_id).toBeTruthy()
expect(props.page_name).toBeTruthy()
expect(props.page_index).toBeTruthy()
})
it("advertises session_id on start_session", async () => {
const start = await findTool("start_session")
expect(start?.inputSchema?.properties?.session_id).toBeTruthy()
expect(start?.inputSchema?.required ?? []).not.toContain("session_id")
})
it("lists the saved diagrams with their pages, without a session", async () => {
const result = await callTool("list_saved_diagrams", {})
expect(result.isError).toBeFalsy()
const text = textOf(result)
const line = text.split("\n").find((l) => l.startsWith(SAVED_ID))
expect(line, text).toBeTruthy()
expect(line).toContain("pages: Flow (3 cells)")
expect(line).toContain(path.join(dataDir, `${SAVED_ID}.drawio`))
expect(line).not.toContain("(current)")
})
it("advertises screenshot on create_new_diagram and edit_diagram", async () => {
for (const name of ["create_new_diagram", "edit_diagram"]) {
const props = await properties(name)
const screenshot = props.screenshot as { type?: string } | undefined
expect(screenshot?.type, `${name} screenshot`).toBe("boolean")
}
})
it("advertises name/id/xml on add_page", async () => {
const props = await properties("add_page")
expect(props.name).toBeTruthy()
expect(props.id).toBeTruthy()
expect(props.xml).toBeTruthy()
})
it("advertises steps_back on restore_version", async () => {
const props = await properties("restore_version")
expect(props.steps_back).toBeTruthy()
})
it("refuses restore_version without a session", async () => {
const result = await callTool("restore_version", {})
expect(result.isError).toBe(true)
expect(textOf(result)).toContain("start_session")
})
it("keeps every description and the instructions within the host limit", async () => {
for (const tool of await listTools()) {
expect(
tool.description?.length,
`${tool.name} description length`,
).toBeLessThanOrEqual(MAX_DESCRIPTION)
}
const instructions = client.getInstructions() ?? ""
expect(instructions).toContain("start_session")
expect(instructions.length).toBeLessThanOrEqual(MAX_DESCRIPTION)
})
it("serves a shape library without a session", async () => {
const result = await callTool("get_shape_library", { library: "AWS4" })
expect(result.isError).toBeFalsy()
expect(textOf(result)).toContain("mxgraph.aws4")
})
it("reports an unknown shape library with the available names", async () => {
const result = await callTool("get_shape_library", {
library: "../secrets",
})
expect(result.isError).toBe(true)
expect(textOf(result)).toContain("kubernetes")
})
it("serves the drawing guide without a session", async () => {
const text = textOf(await callTool("get_drawing_guide", {}))
expect(text).toContain("Edge routing rules")
expect(text).toContain("do not describe the diagram")
expect(text).toContain("clear the canvas")
expect(text.length).toBeLessThanOrEqual(15000)
})
it("appends the user's instructions.md to the drawing guide", async () => {
const text = textOf(await callTool("get_drawing_guide", {}))
expect(
text.endsWith(`\n\n## Custom Instructions\n${CUSTOM_RULE}`),
).toBe(true)
})
it("advertises topic on get_drawing_guide", async () => {
const props = await properties("get_drawing_guide")
expect(props.topic).toBeTruthy()
})
it("serves the table XML reference with topic=tables", async () => {
const result = await callTool("get_drawing_guide", { topic: "tables" })
expect(result.isError).toBeFalsy()
const text = textOf(result)
expect(text).toContain("shape=table")
expect(text).not.toContain("Edge routing rules")
})
})
describe("load_diagram dual-source arguments", () => {
it("advertises both optional 'path' and 'xml' sources", async () => {
const load = await findTool("load_diagram")
const props = load?.inputSchema?.properties ?? {}
expect(props.path).toBeTruthy()
expect(props.xml).toBeTruthy()
const required: string[] = load?.inputSchema?.required ?? []
expect(required).not.toContain("path")
expect(required).not.toContain("xml")
})
it("rejects passing both 'path' and 'xml'", async () => {
// Argument validation fires before the session check: no session
// exists in this harness, so a both-args call must report the
// mutual-exclusion error, not "No active session".
const result = await callTool("load_diagram", {
path: "/tmp/x.drawio",
xml: "",
})
expect(result.isError).toBe(true)
expect(textOf(result)).toContain("not both")
})
it("rejects passing neither 'path' nor 'xml'", async () => {
const result = await callTool("load_diagram", {})
expect(result.isError).toBe(true)
expect(textOf(result)).toContain("either 'path'")
})
it("accepts 'xml' alone as a source (fails only on the missing session)", async () => {
const result = await callTool("load_diagram", {
xml: '',
})
expect(result.isError).toBe(true)
expect(textOf(result)).toContain("No active session")
})
})