TUI: saveResult.queue.test.ts hard-codes POSIX paths, so coverage:tui fails on Windows (not covered by #2748) #2810

Which version line?

v2 — current (@modelcontextprotocol/inspector@latest)

Which client?

TUI

Inspector version

2.12.0 (v2/main at 72126af)

Node version

v24.14.0

Operating system (and browser, for the web client)

Windows 11 Home 10.0.26200 (PowerShell and Git Bash); npm 11.9.0 (CI pins 11.20.0)

Transport

Not applicable / never connected

MCP server under inspection

Not applicable. This is a unit-test failure; no server is involved.

Steps to reproduce

1. On Windows 11 with Node 24: git clone --branch v2/main https://github.com/modelcontextprotocol/inspector.git, then cd inspector && npm ci
2. cd clients/tui
3. npx vitest run __tests__/saveResult.queue.test.ts (or npm run coverage:tui from the repo root)

Expected behavior

Both tests in saveResultToFile queueing (#2571) pass on every platform, because coverage:tui is a stage of npm run local:gate.

Actual behavior

2 of 2 tests fail. saveResultToFile resolves its target with node:path resolve(cwd, path), so with cwd = "/d" the mocked writeFile receives D:\d\a.json, but the test asserts the literal "/d/a.json":

• starts each write only after the previous one has settled: AssertionError: expected [ 'D:\d\a.json' ] to deeply equal [ '/d/a.json' ]
• a failed save does not hold up the ones queued after it: AssertionError: expected [] to have a length of 1 but got +0. This one is a consequence, not a second bug: the first test throws before it settles its mocked write, the module-scope saveQueue in src/utils/saveResult.ts stays blocked behind it, and writes is empty in the second test.

Full npm run coverage:tui on Windows: 1 failed file, 2 failed tests of 639. #2748 lists test:scripts, coverage:web and coverage:mcpdo as the Windows failures; this stage is not in it, and the gate chain aborts before reaching it.

Logs, errors, or screenshots

AssertionError: expected [ 'D:\d\a.json' ] to deeply equal [ '/d/a.json' ]
AssertionError: expected [] to have a length of 1 but got +0

Already prototyped a fix?

Prompt (reconstructed: the change was made interactively with Claude Code on my clone, not from one stored prompt; this prompt reproduces it):

In clients/tui/tests/saveResult.queue.test.ts the expected paths are POSIX literals ("/d/a.json", "/d/b.json", "/d/x.json", "/d/y.json") but saveResultToFile in clients/tui/src/utils/saveResult.ts builds its target with node:path resolve(cwd, path), so on Windows the mocked writeFile receives "D:\d\a.json" and both tests fail. Change only the test: import { resolve } from "node:path", add const inD = (name: string) => resolve("/d", name), and use inD("a.json") etc. in the four assertions. Do not change the source, do not skip on win32, do not mock node:path. Then run npx vitest run __tests__/saveResult.queue.test.ts and npm run check in clients/tui, and npm run coverage:tui from the root.

Verified: before, npm run coverage:tui on Windows 11 / Node 24.14 gave 2 failed of 639. After: 48 files, 640 tests pass; coverage S 97.51 / B 94.75 / F 97.68 / L 97.83; npm run check in clients/tui exits 0. On POSIX resolve("/d", "a.json") is "/d/a.json", so the assertions are unchanged there (I could not run Linux locally). The change is 12 insertions and 4 deletions in the one test file. For reference only, it is on my fork (I am not opening a PR, per CONTRIBUTING): v2/main...Sonica-B:inspector:v2/fix/tui-save-queue-test-windows-paths

AI disclosure (MCP AI_POLICY.md): this report and the fix were produced primarily with Claude Code running on my machine: the Windows test runs, the root-cause analysis, the 16-line test change, and the drafting of this issue.

Before you submit

• I searched existing issues and this is not a duplicate.
• This is not a security vulnerability report (those go through the private advisory process).