write-tests

name	write-tests
description	Write or update tests for a module or feature. Use when asked to write tests, add test coverage, or verify functionality for deep6.

Write Tests for deep6

Write or update tests for the deep6 library.

Steps

1. Identify the module or feature to test. Read its source code to understand the public API.
2. Choose the appropriate test file based on what you're testing:
   • tests/test-env.js — Env class, Variable, aliases, push/pop/revert
   • tests/test-unify.js — Core unification (primitives, arrays, objects, variables, circular, flags)
   • tests/test-match.js — Pattern matching (open, soft, preprocess)
   • tests/test-registry.js — Type registries (Date, RegExp, typed arrays, Set, Map, filters)
   • tests/test-unifiers.js — matchString, matchTypeOf, matchInstanceOf, matchCondition, ref
   • tests/test-traverse.js — walk, clone, assemble, deref
   • tests/test-index.js — Main API (equal, match, clone, isShape), replaceVars
3. Add test functions to the exported array in the chosen file.
4. Run tests to verify: npm test
5. Report results and any failures.

Test harness

Tests use a custom harness in tests/harness.js. Each test file imports submit and TEST, exports a default array of test functions:

import unify from '../src/unify.js';
import {submit, TEST} from './harness.js';

export default [
  function test_my_feature() {
    eval(TEST('unify(1, 1)'));
    eval(TEST('!unify(1, 2)'));

    let result = unify({a: 1}, {a: 1});
    eval(TEST('result'));
  }
];

Conventions

• Import source modules with relative paths: import {equal} from '../src/index.js';
• Import {submit, TEST} from ./harness.js.
• Use eval(TEST('expression')) for assertions — the expression is both the test and the message.
• Name test functions test_descriptive_name.
• Test both success and failure cases.
• Test with various types: objects, arrays, Map, Set, Date, RegExp, typed arrays.
• Test circular reference handling where applicable.