#!/usr/bin/env node
// Turns the per-test istanbul samples in .nyc_output into coverage/lcov.info for
// SonarQube to import.
//
// The check below is the point of this script existing rather than the pipeline
// just calling `nyc report`. The failure mode that matters here is not an error,
// it is silence: if the dev server was started without COVERAGE, every test still
// passes and every page reports no instrumentation, so .nyc_output stays empty
// and nyc cheerfully writes a valid, empty report. SonarQube then shows frontend
// coverage at 0%, which reads as "the tests stopped covering things" rather than
// "collection was never switched on".
//
// This project has been bitten twice by tools succeeding while measuring nothing
// — SonarQube skipping the entire frontend and still exiting EXECUTION SUCCESS
// (#67), and an ESLint matcher silently matching no files (#60). Coverage has the
// same shape, so it fails loudly instead.
const { existsSync, readdirSync } = require('fs');
const { execFileSync } = require('child_process');
const path = require('path');

const root = path.resolve(__dirname, '..');
const nycOutput = path.join(root, '.nyc_output');

const samples = existsSync(nycOutput)
  ? readdirSync(nycOutput).filter((f) => f.endsWith('.json'))
  : [];

if (samples.length === 0) {
  console.error('No coverage was collected — .nyc_output holds no samples.');
  console.error('');
  console.error('The tests may well have passed; that is the problem. Coverage is only');
  console.error('gathered when the dev server is instrumented, which happens when COVERAGE=true');
  console.error('reaches it. Run the suite with `npm run test:e2e:cov` rather than `npm run test:e2e`.');
  console.error('');
  console.error('If it was run that way, check that Playwright started its own dev server rather');
  console.error('than reusing one you already had open — an uninstrumented server collects nothing.');
  process.exit(1);
}

console.log(`Merging ${samples.length} coverage sample(s) from ${samples.length} test(s).`);

// Invoked through nyc's own entry point rather than npx: on Windows, spawning
// the npx.cmd shim fails with EINVAL under current Node unless a shell is used,
// and running the JS directly avoids needing one at all.
execFileSync(
  process.execPath,
  [
    path.join(root, 'node_modules', 'nyc', 'bin', 'nyc.js'),
    'report',
    '--reporter=lcov',
    '--reporter=text-summary',
    '--report-dir',
    'coverage'
  ],
  { cwd: root, stdio: 'inherit' }
);

const lcov = path.join(root, 'coverage', 'lcov.info');
if (!existsSync(lcov)) {
  console.error(`nyc reported success but ${lcov} was not written.`);
  process.exit(1);
}
console.log(`Wrote ${path.relative(root, lcov)}`);