/**
 * Config startup error test — locks in the [E00-S04-T02] guarantee that a
 * missing required setting gives a field-specific startup error.
 *
 * Acceptance criteria covered (each test fails without the committed state):
 *   - "missing required setting gives a field-specific startup error" → the
 *     `packages/config` package exposes the startup validation entry point
 *     (`assertValidConfig`, building on the E00-S04-T01 TypeBox/Ajv schema)
 *     and the environment adapter (`loadConfigFromEnv`, E00-S04-T04 — the
 *     config package's single owner of `process.env` reads) validates the
 *     mapped environment through it; the committed `apps/server/src/index.ts`
 *     loads its startup configuration through the adapter before the server
 *     binds, so a deployment missing a required setting (the admin-session
 *     secret `EPPP_SESSION_SECRET` — the schema's required field,
 *     Security-and-Operations §32/§26) fails fast at startup instead of
 *     booting with an invalid configuration. Locked in statically (mutation
 *     probes prove non-vacuity: dropping the adapter call, moving it after
 *     the bind, or dropping the compose/Dockerfile support all fail) and
 *     behaviorally by the deterministic probes (the issue's test plan: "start
 *     with a missing required field and confirm the error names it" — booting
 *     the committed server without `EPPP_SESSION_SECRET` exits non-zero with
 *     the error naming the missing field).
 *   - "the error names the missing field" → a missing required setting throws
 *     `MissingRequiredSettingError` whose message and `missingField` name the
 *     missing field (e.g. `"missing required setting: sessionSecret"`); other
 *     schema violations throw `ConfigStartupError` whose message names the
 *     violating field too. Locked in statically and by the deterministic
 *     probes (boundary + booted server).
 *   - the compose stack and the server image stay runnable with the required
 *     secret: `compose.yaml` provides `EPPP_SESSION_SECRET` for the `app`
 *     service (dev-only default, ≥ 32 chars — override via .env / shell) and
 *     the `apps/server/Dockerfile` ships the compiled `packages/config` next
 *     to the other workspace deps, so the app container boots (the
 *     deterministic probe boots with a valid secret and `GET /health` answers
 *     200 — a valid startup still works).
 *
 * Run: `node --test tests/config-startup-error.test.mjs`
 * (node:test — built into Node >= 18; no dependencies, lockfile untouched.
 * The deterministic probes boot the committed server, which imports
 * `@personal-blog/config` and `@personal-blog/database-postgres` — build those
 * packages first, exactly as the CI job does.)
 */

import test from 'node:test';
import assert from 'node:assert/strict';
import { readFileSync, existsSync, writeFileSync, rmSync } from 'node:fs';
import { spawn, spawnSync } from 'node:child_process';
import { once } from 'node:events';
import { createServer as createNetServer } from 'node:net';
import path from 'node:path';
import { fileURLToPath } from 'node:url';

const REPO_ROOT = path.resolve(path.dirname(fileURLToPath(import.meta.url)), '..');

const read = (relPath) => readFileSync(path.join(REPO_ROOT, relPath), 'utf8');

/** The committed config package and server entrypoint under test. */
const CONFIG_DIR = 'packages/config';
const STARTUP_SRC = `${CONFIG_DIR}/src/startup.ts`;
const INDEX_SRC = `${CONFIG_DIR}/src/index.ts`;
const SERVER_SRC = 'apps/server/src/index.ts';
const COMPOSE_PATH = 'compose.yaml';
const DOCKERFILE_PATH = 'apps/server/Dockerfile';

/** The root test glob (root `scripts.test`, E00-S01-T12) that runs every suite. */
const ROOT_TEST_GLOB = 'tests/**/*.test.mjs';

/** The CI job that gates the startup-error criterion on every PR. */
const CI_JOB = 'config-startup-error';

const delay = (ms) => new Promise((resolve) => setTimeout(resolve, ms));

// ---------------------------------------------------------------------------
// Static assertions on the committed sources
// ---------------------------------------------------------------------------

/**
 * Asserts the config package exposes the field-specific startup error: the
 * startup module compiles the TypeBox `configSchema` with Ajv and exports
 * `assertValidConfig` plus the field-specific errors — `ConfigStartupError`
 * for any schema violation, and `MissingRequiredSettingError` (whose message
 * and `missingField` name the missing field, e.g.
 * `"missing required setting: sessionSecret"`) for a missing required
 * setting. Fails fast on a deviation; the mutation probes below prove the
 * assertions are non-vacuous.
 */
function assertStartupErrorSource(src) {
  // Built on the E00-S04-T01 schema boundary: the module compiles the
  // TypeBox configSchema with Ajv (same golden-tuple validator as
  // validate.ts) and derives the missing-field names from the Ajv `required`
  // keyword errors.
  assert.match(
    src,
    /import \{ Ajv, type ErrorObject \} from 'ajv'/,
    'the startup module must import Ajv (the golden-tuple validator) and the ErrorObject type',
  );
  assert.match(
    src,
    /import \{ configSchema, type Config \} from '\.\/schema\.js'/,
    'the startup module must build on the committed configSchema (import from ./schema.js)',
  );
  assert.match(
    src,
    /new Ajv\(\{ allErrors: true \}\)/,
    'the startup module must create the Ajv instance with allErrors (report every violation)',
  );
  assert.match(
    src,
    /\.compile\(configSchema\)/,
    'the startup module must compile the TypeBox configSchema with Ajv',
  );

  // The field-specific errors.
  assert.match(
    src,
    /export class ConfigStartupError extends Error/,
    'the startup module must export ConfigStartupError (any invalid configuration is a field-specific startup error)',
  );
  assert.match(
    src,
    /export class MissingRequiredSettingError extends ConfigStartupError/,
    'the startup module must export MissingRequiredSettingError (a missing required setting is the field-specific startup error)',
  );
  assert.match(
    src,
    /missing required setting: \$\{missingField\}/,
    'the MissingRequiredSettingError message must name the missing field ("missing required setting: <field>")',
  );
  assert.match(
    src,
    /readonly missingField: string/,
    'MissingRequiredSettingError must carry the missing field name (missingField)',
  );

  // The startup entry point: validates and throws the field-specific error
  // for a missing required setting (Ajv `required` keyword -> missingProperty).
  assert.match(
    src,
    /export function assertValidConfig\(value: unknown\): Config/,
    'the startup module must export assertValidConfig (the startup validation entry point)',
  );
  assert.match(
    src,
    /error\.keyword === 'required'/,
    'assertValidConfig must detect missing required settings from the Ajv "required" keyword errors',
  );
  assert.match(
    src,
    /throw new MissingRequiredSettingError\(missingFields\.join\(', '\)\)/,
    'assertValidConfig must throw MissingRequiredSettingError naming the missing field(s)',
  );
}

/**
 * Asserts the committed server loads its startup configuration through the
 * environment adapter (E00-S04-T04) before it binds: it imports
 * `loadConfigFromEnv` from `@personal-blog/config` and calls it (the adapter
 * validates the mapped environment with `assertValidConfig`, including the
 * required `EPPP_SESSION_SECRET`) BEFORE `server.listen` — so a missing
 * required setting is a startup error, never a silently-booted invalid
 * configuration, and the server itself never reads `process.env` directly.
 */
function assertServerStartupValidation(src) {
  assert.match(
    src,
    /import \{ loadConfigFromEnv \} from '@personal-blog\/config'/,
    'the server must import the environment adapter (loadConfigFromEnv) from the config package',
  );
  assert.match(
    src,
    /const config = loadConfigFromEnv\(\);/,
    'the server must load its startup configuration through the environment adapter (const config = loadConfigFromEnv())',
  );
  assert.doesNotMatch(
    src,
    /process\.env\.[A-Z_]+/,
    'the server must not read process.env directly (all settings flow through the config adapter, E00-S04-T04)',
  );
  const callIndex = src.indexOf('loadConfigFromEnv(');
  const listenIndex = src.indexOf('server.listen(');
  assert.ok(
    callIndex !== -1 && listenIndex !== -1 && callIndex < listenIndex,
    'the startup configuration must load through the adapter before the server binds (server.listen) so a missing required setting is a startup error',
  );
}

/**
 * Asserts the compose app service provides the required admin-session secret
 * (`EPPP_SESSION_SECRET`) with a dev-only default of at least 32 characters
 * (the schema's required field, Security-and-Operations §32/§26), so
 * `docker compose up -d` keeps working from a clean clone while the app's
 * startup validation has the secret it requires.
 */
function assertComposeSecret(composeText) {
  // The app service block runs from the top-level "  app:" key to the
  // top-level "volumes:" map (the db service has its own nested "volumes:"
  // key earlier, so slice to the root-level one).
  const appBlock = composeText.slice(composeText.indexOf('  app:'), composeText.indexOf('\nvolumes:'));
  assert.match(
    appBlock,
    /EPPP_SESSION_SECRET: \$\{EPPP_SESSION_SECRET:-[^}]{32,}\}/,
    'the app service must provide EPPP_SESSION_SECRET with a >= 32 char dev-only default (${EPPP_SESSION_SECRET:-...}), so the app boots with the required secret from a clean clone',
  );
}

/**
 * Asserts the server image ships the config package: the build stage copies
 * `packages/config` source (the server's build compiles it) and the runtime
 * stage copies the compiled `packages/config/dist` + manifest next to the
 * other workspace deps the server imports.
 */
function assertDockerfileConfig(dockerfile) {
  assert.match(
    dockerfile,
    /COPY packages\/config packages\/config/,
    'the build stage must copy the config package source (the server build compiles its workspace dependency)',
  );
  assert.match(
    dockerfile,
    /COPY --from=build \/app\/packages\/config\/dist \.\/packages\/config\/dist/,
    'the runtime stage must ship the compiled config package (packages/config/dist) so the server import resolves in the image',
  );
}

// ---------------------------------------------------------------------------
// Criterion tests
// ---------------------------------------------------------------------------

test('the config package exposes the field-specific startup error (MissingRequiredSettingError + assertValidConfig)', () => {
  assert.ok(existsSync(path.join(REPO_ROOT, STARTUP_SRC)), `committed ${STARTUP_SRC} must exist`);
  assertStartupErrorSource(read(STARTUP_SRC));
});

test('the package boundary re-exports the startup validation entry point and its errors', () => {
  const src = read(INDEX_SRC);
  assert.match(
    src,
    /export \{ assertValidConfig, ConfigStartupError, MissingRequiredSettingError \} from '\.\/startup\.js'/,
    'the boundary must re-export assertValidConfig and the field-specific startup errors',
  );
});

test('the server validates the required settings at startup, before it binds', () => {
  assert.ok(existsSync(path.join(REPO_ROOT, SERVER_SRC)), `committed ${SERVER_SRC} must exist`);
  assertServerStartupValidation(read(SERVER_SRC));
});

test('the compose app service provides the required admin-session secret (EPPP_SESSION_SECRET)', () => {
  assertComposeSecret(read(COMPOSE_PATH));
});

test('the server image ships the config package (build source + runtime dist)', () => {
  assertDockerfileConfig(read(DOCKERFILE_PATH));
});

test('the config-startup-error criterion is enforced in CI', () => {
  // Picked up by the root test command (root `scripts.test` glob).
  const scripts = JSON.parse(read('package.json')).scripts ?? {};
  assert.equal(
    scripts.test,
    `node --test "${ROOT_TEST_GLOB}"`,
    `root scripts.test must run the "${ROOT_TEST_GLOB}" glob so this suite runs with the rest`,
  );
  // And a dedicated CI job gates it on every PR.
  const workflow = read('.gitea/workflows/ci.yml');
  assert.ok(
    workflow.includes(`node --test tests/config-startup-error.test.mjs`),
    `CI must run the config-startup-error suite (job "${CI_JOB}") on every PR`,
  );
  assert.ok(
    workflow.includes(
      'pnpm --filter @personal-blog/config build && pnpm --filter @personal-blog/database-postgres build',
    ),
    'the CI job must build the config and database-postgres packages (the probes boot the committed server which imports them)',
  );
});

// ---------------------------------------------------------------------------
// Mutation probes — the static assertions are non-vacuous
// ---------------------------------------------------------------------------

test('dropping the adapter call fails the server wiring assertion (mutation probe)', () => {
  const src = read(SERVER_SRC);
  const withoutCall = src.replace('const config = loadConfigFromEnv();', 'const configX = loadConfigFromEnv();');
  assert.notEqual(withoutCall, src, 'the mutation must actually break the loadConfigFromEnv wiring');
  assert.throws(() => assertServerStartupValidation(withoutCall), /must load its startup configuration/);
});

test('moving the adapter call after the server binds fails the order assertion (mutation probe)', () => {
  const src = read(SERVER_SRC);
  const moved = src
    .replace('const config = loadConfigFromEnv();\n', '')
    .replace(
      'server.listen(config.port, config.host, () => {',
      'server.listen(config.port, config.host, () => {\n  const config = loadConfigFromEnv();',
    );
  assert.notEqual(moved, src, 'the mutation must actually move the adapter call after the bind');
  assert.throws(() => assertServerStartupValidation(moved), /before the server binds/);
});

test('the server reading process.env directly fails the no-direct-read assertion (mutation probe)', () => {
  const src = read(SERVER_SRC);
  const directRead = src.replace(
    'const config = loadConfigFromEnv();',
    'const config = loadConfigFromEnv();\nconst PORT = process.env.PORT;',
  );
  assert.notEqual(directRead, src, 'the mutation must actually add a direct process.env read');
  assert.throws(() => assertServerStartupValidation(directRead), /must not read process\.env/);
});

test('an error message that does not name the missing field fails the naming assertion (mutation probe)', () => {
  const src = read(STARTUP_SRC);
  const noField = src.replace(/missing required setting: \$\{missingField\}/g, 'missing required setting');
  assert.notEqual(noField, src, 'the mutation must actually drop the field name from the message');
  assert.throws(() => assertStartupErrorSource(noField), /must name the missing field/);
});

test('dropping MissingRequiredSettingError fails the field-specific error assertion (mutation probe)', () => {
  const src = read(STARTUP_SRC);
  const noError = src.replace('export class MissingRequiredSettingError extends ConfigStartupError', 'export class MissingRequiredSettingErrorX extends ConfigStartupError');
  assert.notEqual(noError, src, 'the mutation must actually rename the error class');
  assert.throws(() => assertStartupErrorSource(noError), /must export MissingRequiredSettingError/);
});

test('dropping the missing-field detection fails the required-setting assertion (mutation probe)', () => {
  const src = read(STARTUP_SRC);
  const noDetection = src.replace("error.keyword === 'required'", "error.keyword === 'minLength'");
  assert.notEqual(noDetection, src, 'the mutation must actually change the missing-field detection');
  assert.throws(() => assertStartupErrorSource(noDetection), /"required" keyword/);
});

test('removing EPPP_SESSION_SECRET from the compose app service fails the compose assertion (mutation probe)', () => {
  const composeText = read(COMPOSE_PATH);
  const withoutSecret = composeText.replace(
    /      EPPP_SESSION_SECRET: \$\{EPPP_SESSION_SECRET:-[^}]*\}\n/,
    '',
  );
  assert.notEqual(withoutSecret, composeText, 'the mutation must actually remove the secret env entry');
  assert.throws(() => assertComposeSecret(withoutSecret), /EPPP_SESSION_SECRET/);
});

test('dropping the config package from the image fails the Dockerfile assertion (mutation probe)', () => {
  const dockerfile = read(DOCKERFILE_PATH);
  const withoutDist = dockerfile.replace(
    'COPY --from=build /app/packages/config/dist ./packages/config/dist\n',
    '',
  );
  assert.notEqual(withoutDist, dockerfile, 'the mutation must actually drop the runtime dist copy');
  assert.throws(() => assertDockerfileConfig(withoutDist), /runtime stage must ship the compiled config package/);
});

// ---------------------------------------------------------------------------
// Deterministic behavioral probe — the issue's test plan: "start with a
// missing required field and confirm the error names it"
// ---------------------------------------------------------------------------

/**
 * How the current Node executes TypeScript sources: `default` (>= 23.6, type
 * stripping on by default), `strip-types-flag` (>= 22.6 via
 * `--experimental-strip-types`) or `null` (cannot run .ts at all). The
 * workspace pins engines.node to 24.x, where type stripping is stable.
 */
function tsExecMode() {
  const [major, minor] = process.versions.node.split('.').map(Number);
  if (major > 23 || (major === 23 && minor >= 6)) return 'default';
  if (major === 22 && minor >= 6) return 'strip-types-flag';
  return null;
}

/** True when this Node can execute the committed `.ts` server source (>= 22.6, type stripping). */
const TS_STRIPPING = tsExecMode() !== null;

/** The compiled config package boundary the probes import (built by the CI job first). */
const CONFIG_DIST = existsSync(path.join(REPO_ROOT, CONFIG_DIR, 'dist', 'index.js'));
/** The compiled database-postgres package the booted server also imports. */
const DATABASE_POSTGRES_DIST = existsSync(
  path.join(REPO_ROOT, 'packages/database-postgres', 'dist', 'index.js'),
);

/** Why the boot probes may be skipped on a clean clone without a build step. */
const BUILD_HINT =
  'build the config and database-postgres packages first (pnpm --filter @personal-blog/config build && pnpm --filter @personal-blog/database-postgres build)';

/**
 * The boundary probe source: exercises the compiled `@personal-blog/config`
 * startup boundary (`assertValidConfig` + the field-specific errors) exactly
 * as the server consumes it — a valid configuration passes (including the
 * no-database local path), a missing required setting throws
 * `MissingRequiredSettingError` naming the field, and other violations throw
 * `ConfigStartupError` naming the violating field. Written to a temp file
 * inside `packages/config/` so `ajv`/`@sinclair/typebox` resolve through the
 * package's own dependency links, then removed.
 */
const PROBE_SOURCE = `
import { assertValidConfig, ConfigStartupError, MissingRequiredSettingError } from './dist/index.js';

const capture = (fn) => {
  try {
    return { threw: false, value: fn() };
  } catch (error) {
    return {
      threw: true,
      name: error && typeof error === 'object' ? error.name : String(error),
      message: error instanceof Error ? error.message : String(error),
      missingField: error && typeof error === 'object' ? error.missingField : undefined,
      isMissingRequired: error instanceof MissingRequiredSettingError,
      isConfigStartup: error instanceof ConfigStartupError,
    };
  }
};

const result = {
  // A valid configuration passes and is returned — including the local
  // non-container path with no databaseUrl (host/port/databaseUrl optional).
  validReturnsConfig: capture(() => assertValidConfig({ sessionSecret: 's'.repeat(32) })).threw === false,
  fullValid: capture(() => assertValidConfig({ host: '0.0.0.0', port: 3000, databaseUrl: 'postgres://eppp:eppp@db:5432/eppp', sessionSecret: 's'.repeat(32) })).threw === false,
  // The issue's test plan: start with a missing required field — the error
  // must be MissingRequiredSettingError and name the missing field.
  missingSecret: capture(() => assertValidConfig({ host: '0.0.0.0', port: 3000 })),
  // Other violations are field-specific too (the message names the field).
  shortSecret: capture(() => assertValidConfig({ sessionSecret: 'short' })),
  unknownProperty: capture(() => assertValidConfig({ sessionSecret: 's'.repeat(32), extra: true })),
};

console.log('CONFIG_STARTUP_PROBE_RESULT ' + JSON.stringify(result));
`;

test('the compiled startup boundary throws a field-specific error naming the missing required setting (deterministic probe)', { skip: !CONFIG_DIST ? BUILD_HINT : false }, () => {
  const probeFile = path.join(REPO_ROOT, CONFIG_DIR, `.config-startup-probe-${process.pid}.mjs`);
  try {
    writeFileSync(probeFile, PROBE_SOURCE);
    const run = spawnSync(process.execPath, [path.basename(probeFile)], {
      cwd: path.join(REPO_ROOT, CONFIG_DIR),
      encoding: 'utf8',
      timeout: 60_000,
    });
    assert.equal(
      run.status,
      0,
      `the probe must exit 0 (status ${run.status}):\n${(run.stderr || run.stdout || '').trim()}`,
    );
    const match = run.stdout.match(/CONFIG_STARTUP_PROBE_RESULT (\{.*\})/);
    assert.ok(match, `the probe must print CONFIG_STARTUP_PROBE_RESULT:\n${run.stdout.trim()}`);
    const result = JSON.parse(match[1]);

    // A valid configuration passes (including the no-database local path).
    assert.equal(result.validReturnsConfig, true, 'a valid config (only the required secret) must pass assertValidConfig');
    assert.equal(result.fullValid, true, 'a full valid config must pass assertValidConfig');

    // Missing required setting: field-specific startup error naming the field.
    assert.equal(result.missingSecret.threw, true, 'a config missing the required secret must throw');
    assert.equal(result.missingSecret.isMissingRequired, true, 'a missing required setting must throw MissingRequiredSettingError');
    assert.equal(result.missingSecret.isConfigStartup, true, 'MissingRequiredSettingError must be a ConfigStartupError');
    assert.equal(
      result.missingSecret.missingField,
      'sessionSecret',
      `MissingRequiredSettingError must carry the missing field name (got: ${JSON.stringify(result.missingSecret)})`,
    );
    assert.match(
      result.missingSecret.message,
      /missing required setting: sessionSecret/,
      `the startup error must name the missing field (got: ${JSON.stringify(result.missingSecret)})`,
    );

    // Other violations are field-specific too.
    assert.equal(result.shortSecret.threw, true, 'a too-short secret must throw');
    assert.equal(result.shortSecret.isMissingRequired, false, 'a too-short secret is not a missing required setting');
    assert.equal(result.shortSecret.isConfigStartup, true, 'a too-short secret must throw ConfigStartupError');
    assert.match(
      result.shortSecret.message,
      /sessionSecret/,
      `the startup error must name the violating field (got: ${JSON.stringify(result.shortSecret)})`,
    );
    assert.equal(result.unknownProperty.threw, true, 'an unknown property must throw');
    assert.match(
      result.unknownProperty.message,
      /extra/,
      `the startup error must name the unexpected field (got: ${JSON.stringify(result.unknownProperty)})`,
    );
  } finally {
    rmSync(probeFile, { force: true });
  }
});

// ---------------------------------------------------------------------------
// Server-boot probes — the issue's test plan executed against the real
// committed startup: "start with a missing required field and confirm the
// error names it"
// ---------------------------------------------------------------------------

/** Reserves an ephemeral TCP port, then releases it for the child to bind. */
function reservePort() {
  return new Promise((resolve, reject) => {
    const probe = createNetServer();
    probe.once('error', reject);
    probe.listen(0, '127.0.0.1', () => {
      const address = probe.address();
      const port = typeof address === 'object' && address !== null ? address.port : 0;
      probe.close(() => resolve(port));
    });
  });
}

/**
 * Boots the committed server source on `port` with the given env overrides.
 * An inherited `DATABASE_URL` (the no-database path must be deterministic)
 * and `EPPP_SESSION_SECRET` (the missing-secret case must be deterministic)
 * are stripped unless explicitly provided. Returns `{ child, stdout, stderr }`
 * with closures for diagnostics.
 */
function bootServer(port, envOverrides = {}) {
  const args =
    tsExecMode() === 'strip-types-flag'
      ? ['--experimental-strip-types', SERVER_SRC]
      : [SERVER_SRC];
  const env = { ...process.env, PORT: String(port) };
  delete env.DATABASE_URL;
  delete env.EPPP_SESSION_SECRET;
  Object.assign(env, envOverrides);
  const child = spawn(process.execPath, args, {
    cwd: REPO_ROOT,
    env,
    stdio: ['ignore', 'pipe', 'pipe'],
  });
  let stdout = '';
  let stderr = '';
  child.stdout.on('data', (chunk) => {
    stdout += String(chunk);
  });
  child.stderr.on('data', (chunk) => {
    stderr += String(chunk);
  });
  return { child, stdout: () => stdout, stderr: () => stderr };
}

/** Waits for the child to exit (it fails fast on a startup error). */
function waitForExit(child, deadlineMs = 10_000) {
  return new Promise((resolve, reject) => {
    if (child.exitCode !== null || child.signalCode !== null) {
      resolve({ code: child.exitCode, signal: child.signalCode });
      return;
    }
    const timer = setTimeout(
      () => reject(new Error('the server did not exit within the deadline (expected a startup error)')),
      deadlineMs,
    );
    child.once('exit', (code, signal) => {
      clearTimeout(timer);
      resolve({ code, signal });
    });
  });
}

/**
 * Polls `GET /health` until the server answers with ANY status, the child
 * exits, or the deadline passes. Returns the fetch Response.
 */
async function waitForAnswer(port, child, stderr, deadlineMs = 10_000) {
  const deadline = Date.now() + deadlineMs;
  let lastError = '';
  while (Date.now() < deadline) {
    if (child.exitCode !== null) {
      throw new Error(
        `the server exited before answering GET /health (code ${child.exitCode}): ${stderr().trim()}`,
      );
    }
    try {
      return await fetch(`http://127.0.0.1:${port}/health`, {
        signal: AbortSignal.timeout(1_000),
      });
    } catch (err) {
      lastError = err instanceof Error ? err.message : String(err);
      await delay(100);
    }
  }
  throw new Error(
    `GET /health did not answer within ${deadlineMs}ms (last error: ${lastError}; server stderr: ${stderr().trim()})`,
  );
}

/** Kills a booted child (SIGTERM, then SIGKILL if needed) and waits for exit. */
async function stopChild(child) {
  if (child.exitCode !== null || child.signalCode !== null) return;
  child.kill('SIGTERM');
  await Promise.race([once(child, 'exit'), delay(2_000)]);
  if (child.exitCode === null && child.signalCode === null) child.kill('SIGKILL');
}

test('starting without the required setting exits non-zero naming the missing field (server boot probe)', { skip: !TS_STRIPPING || !CONFIG_DIST || !DATABASE_POSTGRES_DIST ? BUILD_HINT : false }, async () => {
  // The issue's test plan: "start with a missing required field and confirm
  // the error names it". The committed server validates its required settings
  // at startup, so booting it without EPPP_SESSION_SECRET must fail fast —
  // the process exits non-zero and the error names the missing field.
  const port = await reservePort();
  const { child, stdout, stderr } = bootServer(port); // EPPP_SESSION_SECRET stripped
  const { code, signal } = await waitForExit(child);
  assert.notEqual(
    code,
    0,
    `the server must exit non-zero when a required setting is missing (code ${code}, signal ${signal}); output: ${stdout().trim()} ${stderr().trim()}`,
  );
  assert.match(
    stderr() + stdout(),
    /missing required setting: sessionSecret/,
    `the startup error must name the missing field (sessionSecret); got: ${stdout().trim()} ${stderr().trim()}`,
  );
});

test('starting with an invalid required secret exits non-zero naming the field (server boot probe)', { skip: !TS_STRIPPING || !CONFIG_DIST || !DATABASE_POSTGRES_DIST ? BUILD_HINT : false }, async () => {
  // A required setting that violates the schema (a too-short secret, < 32
  // chars) is also a field-specific startup error naming the field.
  const port = await reservePort();
  const { child, stdout, stderr } = bootServer(port, { EPPP_SESSION_SECRET: 'short' });
  const { code, signal } = await waitForExit(child);
  assert.notEqual(
    code,
    0,
    `the server must exit non-zero when the required secret is invalid (code ${code}, signal ${signal}); output: ${stdout().trim()} ${stderr().trim()}`,
  );
  assert.match(
    stderr() + stdout(),
    /sessionSecret/,
    `the startup error must name the invalid field (sessionSecret); got: ${stdout().trim()} ${stderr().trim()}`,
  );
});

test('starting with the required secret present boots to GET /health 200 (server boot probe)', { skip: !TS_STRIPPING || !CONFIG_DIST || !DATABASE_POSTGRES_DIST ? BUILD_HINT : false }, async () => {
  // The startup validation must not reject a valid configuration: with the
  // required admin-session secret (and no DATABASE_URL — the local
  // non-container path) the server reports ready immediately and GET /health
  // answers 200 {"status":"ok"}.
  const port = await reservePort();
  const { child, stdout, stderr } = bootServer(port, { EPPP_SESSION_SECRET: 's'.repeat(32) });
  try {
    const response = await waitForAnswer(port, child, stderr);
    assert.equal(
      response.status,
      200,
      `GET /health with a valid required secret must answer 200 (got ${response.status}); server output: ${stdout().trim()} ${stderr().trim()}`,
    );
    assert.deepEqual(
      await response.json(),
      { status: 'ok' },
      'the app must report a healthy application ({"status":"ok"}) when the required settings are valid',
    );
  } finally {
    await stopChild(child);
  }
});