a2f5f5c990
* test: create new @pnpm/test-ipc-server private util package * test: use @pnpm/test-ipc-server for previously refactored tests * test: use @pnpm/test-ipc-server for tests using json-append * test: change how --no-bail is passed to avoid passing it to scripts This test began failing after the conversion to use `@pnpm/test-echo-server` since the `--no-bail` script was being passed to scripts. Changing how --no-bail is configured to fix this test. * test: use @pnpm/test-ipc-server in exec/lifecycle fixture tests * test: use @pnpm/test-ipc-server in pkg-manager/headless fixture tests * test: use @pnpm/test-ipc-server in exec/prepare-package fixture tests * test: switch pnpm test from json-append to @pnpm.e2e/hello-world-js-bin * test: fix and re-enable 'rebuild multiple packages in correct order' The pnpm-workspace.yaml file didn't contain all packages, causing: ``` 2023-12-22T02:24:46.2277155Z FAIL test/recursive.ts 2023-12-22T02:24:46.2277881Z ● rebuild multiple packages in correct order 2023-12-22T02:24:46.2278348Z 2023-12-22T02:24:46.2278734Z expect(received).toStrictEqual(expected) // deep equality 2023-12-22T02:24:46.2279302Z 2023-12-22T02:24:46.2279517Z - Expected - 1 2023-12-22T02:24:46.2279932Z + Received + 0 2023-12-22T02:24:46.2280186Z 2023-12-22T02:24:46.2280791Z Array [ 2023-12-22T02:24:46.2281256Z "project-1", 2023-12-22T02:24:46.2281733Z - "project-2", 2023-12-22T02:24:46.2282135Z ] 2023-12-22T02:24:46.2282334Z 2023-12-22T02:24:46.2282475Z 216 | }, []) 2023-12-22T02:24:46.2282870Z 217 | 2023-12-22T02:24:46.2283788Z > 218 | expect(server1.getMessages()).toStrictEqual(['project-1', 'project-2']) 2023-12-22T02:24:46.2284725Z | ^ 2023-12-22T02:24:46.2285802Z 219 | expect(server2.getMessages()).toStrictEqual(['project-1', 'project-3']) 2023-12-22T02:24:46.2286683Z 220 | }) 2023-12-22T02:24:46.2287049Z 221 | 2023-12-22T02:24:46.2287269Z 2023-12-22T02:24:46.2287588Z at Object.<anonymous> (test/recursive.ts:218:33) ```
2.1 KiB
@pnpm/test-ipc-server
The TestIpcServer is a simple Inter-Process Communication (IPC) server written specifically for usage in pnpm tests.
It's a simple wrapper around Node.js's builtin IPC support. Messages sent to the server are saved to a buffer that can be retrieved for assertions.
Rationale
In the past, many pnpm tests contained scripts that wrote output to the same file. Writing to the same file concurrently causes race conditions resulting in flaky CI tests. The race conditions occur due to multiple processes reading a file, appending data, and writing the file back out. If two processes start at the same time and read the same input, one of the process's output would be overwritten by the other.
At the time of writing (December 2023), there's no great cross-platform way to append to a file atomically. From https://www.man7.org/linux/man-pages/man2/open.2.html
O_APPENDmay lead to corrupted files on NFS filesystems if more than one process appends data to a file at once. This is because NFS does not support appending to a file, so the client kernel has to simulate it, which can't be done without a race condition.
The TestIpcServer doesn't drop messages the same way since it's using Node.js's IPC mechanism that is specifically designed to handle multiple clients.
Example
A common testing pattern in the pnpm repo is to ensure package scripts runs as expected or in particular orders.
{
"name": "@pnpm/example-test-fixture",
"private": true,
"scripts": {
"build": "echo 'This script should run'"
}
}
This can be tested through the TestIpcServer,
import { prepare } from '@pnpm/prepare'
import { createTestIpcServer } from '@pnpm/test-ipc-server'
test('example test', async () => {
await using server = await createTestIpcServer()
prepare({
scripts: {
build: server.sendLineScript('this is a built script that should run'),
},
})
await execa('node', [pnpmBin, 'run', 'build'])
expect(server.getLines()).toStrictEqual(['this is a built script that should run'])
})
License
MIT