[Bug]: blob reporter / merge-reports workflow is loosing projects from configuration

[aslushnikov]

Version

latest

Steps to reproduce

1. Prepare a simple playwright testcase:

   mkdir repro && cd repro
   npm init -y
   npm i @playwright/test
   cat <<'EOF' > a.spec.ts
   import { test, expect } from '@playwright/test';
   
   test('should work', async () => {});
   EOF

2. Prepare a smiple custom reporter that logs configuration.projects:

   cat <<'EOF' > reporter.js
   export default class ConfigOnlyReporter {
     onBegin(config) {
       console.log('Playwright config projects:');
       console.log(JSON.stringify(config.projects, null, 2));
     }
   }
   EOF

Expected behavior

By default, i expect custom reporter to receive projects, just like in this case:

npx playwright test --reporter ./reporter.js

Actual behavior

However, when going through blob/merge-reports flow, the projects are NOT PASSED to the custom reporter.

The following logs nothing:

npx playwright test --reporter blob
npx playwright merge-reports ./blob-report --reporter ./reporter.js

Additional context

We discovered this while debugging Flakiness.io integration with https://endform.dev/

Environment

System:
    OS: macOS 15.6.1
    CPU: (10) arm64 Apple M1 Max
    Memory: 241.13 MB / 32.00 GB
  Binaries:
    Node: 24.6.0 - /Users/aslushnikov/.nvm/versions/node/v24.6.0/bin/node
    npm: 11.5.1 - /Users/aslushnikov/.nvm/versions/node/v24.6.0/bin/npm
    pnpm: 10.28.0 - /Users/aslushnikov/.nvm/versions/node/v24.6.0/bin/pnpm
    bun: 1.3.4 - /Users/aslushnikov/.bun/bin/bun
    Deno: 2.0.4 - /Users/aslushnikov/.deno/bin/deno
  IDEs:
    VSCode: 1.108.2 - /usr/local/bin/code
    Cursor: 2.3.41 - /usr/local/bin/cursor
    Claude Code: 2.1.31 - /Users/aslushnikov/.local/bin/claude
  Languages:
    Bash: 3.2.57 - /bin/bash
  npmPackages:
    @playwright/test: ^1.58.1 => 1.58.1