Shade/packages/shade-files/tests/unit/path-policy.test.ts

import { describe, test, expect } from 'bun:test';
import * as fc from 'fast-check';
import { validatePath } from '../../src/index.js';

describe('validatePath — happy path', () => {
  test('accepts simple absolute paths', () => {
    expect(validatePath('/foo')).toEqual({ ok: true, normalized: '/foo' });
    expect(validatePath('/foo/bar/baz.txt')).toEqual({
      ok: true,
      normalized: '/foo/bar/baz.txt',
    });
    expect(validatePath('/')).toEqual({ ok: true, normalized: '/' });
  });

  test('normalizes redundant slashes and dots', () => {
    expect(validatePath('//foo//bar/./baz/').normalized).toBe('/foo/bar/baz');
    expect(validatePath('/./foo').normalized).toBe('/foo');
  });

  test('UTF-8 paths are accepted', () => {
    expect(validatePath('/Документы/файл.txt').normalized).toBe('/Документы/файл.txt');
    expect(validatePath('/絵文字 😀/foo').normalized).toBe('/絵文字 😀/foo');
  });
});

describe('validatePath — security', () => {
  test('rejects raw `..` segments', () => {
    expect(validatePath('/../etc/passwd').ok).toBe(false);
    expect(validatePath('/foo/../etc').ok).toBe(false);
    expect(validatePath('/..').ok).toBe(false);
  });

  test('rejects percent-encoded `..`', () => {
    expect(validatePath('/%2e%2e/etc').ok).toBe(false);
    expect(validatePath('/foo/%2E%2E/etc').ok).toBe(false);
  });

  test('rejects forbidden control bytes', () => {
    expect(validatePath('/foo\x00bar').ok).toBe(false);
    expect(validatePath('/foo\r\nbar').ok).toBe(false);
    expect(validatePath('/foo\x7f').ok).toBe(false);
    expect(validatePath('/foo\x01').ok).toBe(false);
  });

  test('rejects backslashes (Windows-style)', () => {
    expect(validatePath('/foo\\bar').ok).toBe(false);
  });

  test('rejects relative paths', () => {
    expect(validatePath('foo').ok).toBe(false);
    expect(validatePath('./foo').ok).toBe(false);
    expect(validatePath('').ok).toBe(false);
  });

  test('rejects over-length paths', () => {
    expect(validatePath('/' + 'a'.repeat(4096)).ok).toBe(false);
    expect(validatePath('/foobar', { maxLength: 5 }).ok).toBe(false);
    expect(validatePath('/abc', { maxLength: 5 }).ok).toBe(true);
  });
});

describe('validatePath — rootScope', () => {
  test('accepts paths inside scope', () => {
    expect(
      validatePath('/srv/data/foo', { rootScope: '/srv/data' }).ok,
    ).toBe(true);
    expect(validatePath('/srv/data', { rootScope: '/srv/data' }).ok).toBe(true);
  });

  test('rejects paths outside scope', () => {
    expect(validatePath('/etc/passwd', { rootScope: '/srv/data' }).ok).toBe(false);
    expect(validatePath('/srv/dataX', { rootScope: '/srv/data' }).ok).toBe(false);
    // Boundary check: /srv/database is NOT inside /srv/data
    expect(validatePath('/srv/database/x', { rootScope: '/srv/data' }).ok).toBe(false);
  });
});

describe('validatePath — extra hook', () => {
  test('extra reject takes precedence', () => {
    const result = validatePath('/secret/foo', {
      extra: (p) => (p.includes('secret') ? 'reject' : 'allow'),
    });
    expect(result.ok).toBe(false);
  });

  test('extra allow is the default', () => {
    expect(
      validatePath('/foo', {
        extra: () => 'allow',
      }).ok,
    ).toBe(true);
  });
});

describe('validatePath — property-based', () => {
  test('any string with a forbidden control byte is rejected', () => {
    fc.assert(
      fc.property(
        fc.string({ minLength: 1, maxLength: 100 }),
        fc.constantFrom('\x00', '\x07', '\x0a', '\x0d', '\x7f', '\\'),
        (prefix, bad) => {
          const p = `/${prefix}${bad}`;
          expect(validatePath(p).ok).toBe(false);
        },
      ),
      { numRuns: 200 },
    );
  });

  test('any path inside rootScope normalizes within rootScope', () => {
    fc.assert(
      fc.property(
        fc.array(fc.string({ minLength: 1, maxLength: 20 }).filter(
          (s) => /^[A-Za-z0-9_-]+$/.test(s),
        ), { minLength: 1, maxLength: 5 }),
        (segments) => {
          const root = '/srv';
          const path = `${root}/${segments.join('/')}`;
          const r = validatePath(path, { rootScope: root });
          if (r.ok) {
            expect(r.normalized.startsWith(root)).toBe(true);
          }
        },
      ),
      { numRuns: 200 },
    );
  });
});