frontend-svelte/src/shared/lib/utils/clampNumber/clampNumber.test.ts

/**
 * Tests for clampNumber utility
 */

import {
    describe,
    expect,
    test,
} from 'vitest';
import { clampNumber } from './clampNumber';

describe('clampNumber', () => {
    describe('basic functionality', () => {
        test('should return value when within range', () => {
            expect(clampNumber(5, 0, 10)).toBe(5);
            expect(clampNumber(0.5, 0, 1)).toBe(0.5);
            expect(clampNumber(-3, -10, 10)).toBe(-3);
        });

        test('should clamp value to minimum', () => {
            expect(clampNumber(-5, 0, 10)).toBe(0);
            expect(clampNumber(-100, -50, 100)).toBe(-50);
            expect(clampNumber(0, 1, 10)).toBe(1);
        });

        test('should clamp value to maximum', () => {
            expect(clampNumber(15, 0, 10)).toBe(10);
            expect(clampNumber(150, -50, 100)).toBe(100);
            expect(clampNumber(100, 1, 50)).toBe(50);
        });

        test('should handle boundary values', () => {
            expect(clampNumber(0, 0, 10)).toBe(0);
            expect(clampNumber(10, 0, 10)).toBe(10);
            expect(clampNumber(-5, -5, 5)).toBe(-5);
            expect(clampNumber(5, -5, 5)).toBe(5);
        });
    });

    describe('negative ranges', () => {
        test('should handle fully negative ranges', () => {
            expect(clampNumber(-5, -10, -1)).toBe(-5);
            expect(clampNumber(-15, -10, -1)).toBe(-10);
            expect(clampNumber(-0.5, -10, -1)).toBe(-1);
        });

        test('should handle ranges spanning zero', () => {
            expect(clampNumber(0, -10, 10)).toBe(0);
            expect(clampNumber(-5, -10, 10)).toBe(-5);
            expect(clampNumber(5, -10, 10)).toBe(5);
        });
    });

    describe('floating-point numbers', () => {
        test('should clamp floating-point values correctly', () => {
            expect(clampNumber(0.75, 0, 1)).toBe(0.75);
            expect(clampNumber(1.5, 0, 1)).toBe(1);
            expect(clampNumber(-0.25, 0, 1)).toBe(0);
        });

        test('should handle very small decimals', () => {
            expect(clampNumber(0.001, 0, 0.01)).toBe(0.001);
            expect(clampNumber(0.1, 0, 0.01)).toBe(0.01);
        });

        test('should handle large floating-point numbers', () => {
            expect(clampNumber(123.456, 100, 200)).toBe(123.456);
            expect(clampNumber(99.999, 100, 200)).toBe(100);
            expect(clampNumber(200.001, 100, 200)).toBe(200);
        });
    });

    describe('edge cases', () => {
        test('should handle when min equals max', () => {
            expect(clampNumber(5, 10, 10)).toBe(10);
            expect(clampNumber(10, 10, 10)).toBe(10);
            expect(clampNumber(15, 10, 10)).toBe(10);
            expect(clampNumber(0, 0, 0)).toBe(0);
        });

        test('should handle zero values', () => {
            expect(clampNumber(0, 0, 10)).toBe(0);
            expect(clampNumber(0, -10, 10)).toBe(0);
            expect(clampNumber(5, 0, 0)).toBe(0);
        });

        test('should handle reversed min/max (min > max)', () => {
            // When min > max, Math.max/Math.min will still produce a result
            // but it's logically incorrect - we test the actual behavior
            // Math.min(Math.max(5, 10), 0) = Math.min(10, 0) = 0
            expect(clampNumber(5, 10, 0)).toBe(0);
            expect(clampNumber(15, 10, 0)).toBe(0);
            expect(clampNumber(-5, 10, 0)).toBe(0);
        });
    });

    describe('special number values', () => {
        test('should handle Infinity', () => {
            expect(clampNumber(Infinity, 0, 10)).toBe(10);
            expect(clampNumber(-Infinity, 0, 10)).toBe(0);
            expect(clampNumber(5, -Infinity, Infinity)).toBe(5);
        });

        test('should handle NaN', () => {
            expect(clampNumber(NaN, 0, 10)).toBeNaN();
        });
    });

    describe('real-world scenarios', () => {
        test('should clamp font size values', () => {
            // Typical font size range: 8px to 72px
            expect(clampNumber(16, 8, 72)).toBe(16);
            expect(clampNumber(4, 8, 72)).toBe(8);
            expect(clampNumber(100, 8, 72)).toBe(72);
        });

        test('should clamp slider values', () => {
            // Slider range: 0 to 100
            expect(clampNumber(50, 0, 100)).toBe(50);
            expect(clampNumber(-10, 0, 100)).toBe(0);
            expect(clampNumber(150, 0, 100)).toBe(100);
        });

        test('should clamp opacity values', () => {
            // Opacity range: 0 to 1
            expect(clampNumber(0.5, 0, 1)).toBe(0.5);
            expect(clampNumber(-0.2, 0, 1)).toBe(0);
            expect(clampNumber(1.2, 0, 1)).toBe(1);
        });

        test('should clamp percentage values', () => {
            // Percentage range: 0 to 100
            expect(clampNumber(75, 0, 100)).toBe(75);
            expect(clampNumber(-5, 0, 100)).toBe(0);
            expect(clampNumber(105, 0, 100)).toBe(100);
        });

        test('should clamp coordinate values', () => {
            // Canvas coordinates: 0 to 800 width, 0 to 600 height
            expect(clampNumber(400, 0, 800)).toBe(400);
            expect(clampNumber(-50, 0, 800)).toBe(0);
            expect(clampNumber(900, 0, 800)).toBe(800);
        });

        test('should clamp font weight values', () => {
            // Font weight range: 100 to 900 (in increments of 100)
            expect(clampNumber(400, 100, 900)).toBe(400);
            expect(clampNumber(50, 100, 900)).toBe(100);
            expect(clampNumber(950, 100, 900)).toBe(900);
        });

        test('should clamp line height values', () => {
            // Line height range: 0.5 to 3.0
            expect(clampNumber(1.5, 0.5, 3.0)).toBe(1.5);
            expect(clampNumber(0.3, 0.5, 3.0)).toBe(0.5);
            expect(clampNumber(4.0, 0.5, 3.0)).toBe(3.0);
        });
    });

    describe('numeric constraints', () => {
        test('should handle very large numbers', () => {
            expect(clampNumber(Number.MAX_VALUE, 0, 100)).toBe(100);
            expect(clampNumber(Number.MIN_VALUE, -10, 10)).toBe(Number.MIN_VALUE);
        });

        test('should handle negative infinity boundaries', () => {
            expect(clampNumber(5, -Infinity, 10)).toBe(5);
            expect(clampNumber(-1000, -Infinity, 10)).toBe(-1000);
        });

        test('should handle positive infinity boundaries', () => {
            expect(clampNumber(5, 0, Infinity)).toBe(5);
            expect(clampNumber(1000, 0, Infinity)).toBe(1000);
        });
    });
});