Test Suite for Configuration Comparison

Goal

Write a comprehensive test suite that validates different equality comparison scenarios for configuration objects. Your tests should demonstrate understanding of when to use different types of equality checks.

Background

A configuration management system needs to validate user settings. Different scenarios require different types of equality checks: some need to verify reference identity, others need deep value comparison, and some need strict type checking.

Requirements

1. Helper Functions

Implement three simple comparison functions in src/compare.js:

• isSameReference(a, b) - Returns true if both arguments reference the exact same value
• isDeepEqual(a, b) - Returns true if values have the same structure and content
• isStrictEqual(a, b) - Returns true if values are equal with strict type checking

These functions can use built-in JavaScript comparison (you don't need to implement custom deep equality logic).

2. Test Suite

Create a comprehensive test suite in src/compare.test.js that tests these comparison functions with various inputs. Your test suite should cover:

Reference Identity Tests

• Primitive values with the same value
• Same object referenced by two variables
• Different objects with identical content

Deep Equality Tests

• Objects with the same properties and values
• Nested objects with matching structure
• Arrays with the same elements
• Objects with different values

Strict Equality Tests

• Sparse arrays (arrays with empty slots) vs arrays with explicit undefined values
• Objects with undefined properties vs objects without those properties

3. Required Test Cases

Test Case 1: Primitive Values { .test }

• Input: Compare number 42 with number 42
• Expected: Reference identity check passes

Test Case 2: Same Object Reference { .test }

• Input: const obj = {name: "test"}; compare obj with itself
• Expected: Reference identity check passes

Test Case 3: Different Object References { .test }

• Input: Compare {id: 1, name: "user"} with a new object {id: 1, name: "user"}
• Expected: Deep equality check passes, but reference identity check fails

Test Case 4: Sparse vs Dense Arrays { .test }

• Input: Compare [1, , 3] (sparse) with [1, undefined, 3] (dense)
• Expected: Strict equality check fails

Dependencies { .dependencies }

jest-circus { .dependency }

Provides testing framework and assertion matchers for validating the configuration validator behavior.