@rpcbase/test helpers

@rpcbase/test ships the shared Playwright wiring we use across RPCBase packages: a preconfigured test/expect, automatic V8 coverage collection, and the rb-test CLI.

1. Declare your coverage config

Create spec/coverage.ts (or .js / .json) in your package:

import path from "node:path"
import { fileURLToPath } from "node:url"

const workspaceRoot = path.resolve(fileURLToPath(new URL("../", import.meta.url)))

export default {
  workspaceRoot,
  libDirs: ["lib"],
  testResultsDir: "test-results",
  thresholds: {
    statements: 75,
    lines: 75,
    functions: 75,
    branches: 60,
  },
}

Only RB_DISABLE_COVERAGE=1 skips the hooks; every other option lives inside this config file.

Per-folder thresholds

Need stricter coverage in a sub-tree? Extend the same thresholds object with glob keys (mirroring Jest's coverageThreshold syntax):

export default {
  workspaceRoot,
  thresholds: {
    global: {
      statements: 90,
      lines: 85,
      functions: 85,
      branches: 70,
    },
    "lib/core/**": {
      statements: 98,
      lines: 95,
    },
    "lib/components/**": {
      functions: 92,
    },
  },
}

• When thresholds only has metric keys, it behaves exactly like before.
• Adding thresholds.global lets you keep a default floor while overriding specific directories.
• Globs run against POSIX-style paths relative to workspaceRoot, but absolute paths work too if you prefer.
• Metrics you omit inside an override inherit from the global thresholds (or the 75/75/75/60 defaults).
• If a glob matches no files you'll get a warning and the override is skipped, so typos are easy to spot.

2. Import test / expect directly

// spec/my-component.spec.ts
import { test, expect } from "@rpcbase/test"

test("renders", async ({ page }) => {
  await page.goto("/playground")
  await expect(page.locator("button"))..toBeVisible()
})

The exported test already records coverage via CDP and writes per-test payloads automatically.

3. Build your Playwright config via the shared wrapper

// playwright.config.ts
import { defineConfig, devices } from "@rpcbase/test"

export default defineConfig({
  testDir: "./spec",
  reporter: [["list"]],
  use: {
    baseURL: "http://localhost:9198",
    launchOptions: { headless: true },
  },
  projects: [
    {
      name: "chromium",
      use: { ...devices["Desktop Chrome"] },
    },
  ],
})

Whenever coverage is enabled, the wrapper appends the shared reporter so Istanbul aggregation + threshold enforcement run after the suite.

4. Run tests with rb-test

Each package uses its npm test script as tsc --noEmit && rb-test. The CLI runs two stages:

• Playwright, with any CLI flags you pass through untouched; repo defaults are applied unless you provide your own --config.

Coverage is enforced separately:

• Playwright uses spec/coverage.* via the shared reporter and will fail the run if thresholds aren’t met.
• Vitest only reads src/coverage.json (JSON object). If that file is missing, Vitest coverage is skipped.

Need to debug without coverage? Set RB_DISABLE_COVERAGE=1 npm test and the Playwright hooks short-circuit.