tech(time): add unit tests for math utils (#5343)

## Description

Adds unit tests for roundToNearest, floorToNearest, ceilToNearest and
circularize in the time entrypoint.

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Author: JeSuisCharlie1

packages/ng/time/core/math.utils.spec.ts

@@ -0,0 +1,147 @@
+import { ceilToNearest, circularize, floorToNearest, roundToNearest } from './math.utils';
+
+describe('MathUtils', () => {
+	describe('roundToNearest', () => {
+		it('should return the value itself when it is already a multiple of the step', () => {
+			// Act
+			const result = roundToNearest(30, 15);
+
+			// Assert
+			expect(result).toBe(30);
+		});
+
+		it('should round down when the value is below the half step', () => {
+			// Act
+			const result = roundToNearest(37, 15);
+
+			// Assert
+			expect(result).toBe(30);
+		});
+
+		it('should round up when the value is above the half step', () => {
+			// Act
+			const result = roundToNearest(38, 15);
+
+			// Assert
+			expect(result).toBe(45);
+		});
+
+		it('should round negative values', () => {
+			// Act
+			const result = roundToNearest(-23, 5);
+
+			// Assert
+			expect(result).toBe(-25);
+		});
+	});
+
+	describe('floorToNearest', () => {
+		it('should return the value itself when it is already a multiple of the step', () => {
+			// Act
+			const result = floorToNearest(30, 15);
+
+			// Assert
+			expect(result).toBe(30);
+		});
+
+		it('should round down even when the value is close to the next step', () => {
+			// Act
+			const result = floorToNearest(44, 15);
+
+			// Assert
+			expect(result).toBe(30);
+		});
+
+		it('should round negative values towards minus infinity', () => {
+			// Act
+			const result = floorToNearest(-23, 5);
+
+			// Assert
+			expect(result).toBe(-25);
+		});
+	});
+
+	describe('ceilToNearest', () => {
+		it('should return the value itself when it is already a multiple of the step', () => {
+			// Act
+			const result = ceilToNearest(30, 15);
+
+			// Assert
+			expect(result).toBe(30);
+		});
+
+		it('should round up even when the value is close to the previous step', () => {
+			// Act
+			const result = ceilToNearest(31, 15);
+
+			// Assert
+			expect(result).toBe(45);
+		});
+
+		it('should round negative values towards plus infinity', () => {
+			// Act
+			const result = ceilToNearest(-23, 5);
+
+			// Assert
+			expect(result).toBe(-20);
+		});
+	});
+
+	describe('circularize', () => {
+		it('should return 0 for 0', () => {
+			// Act
+			const result = circularize(0, 10);
+
+			// Assert
+			expect(result).toBe(0);
+		});
+
+		it('should return max instead of 0 when the value is max', () => {
+			// Act
+			const result = circularize(10, 10);
+
+			// Assert
+			expect(result).toBe(10);
+		});
+
+		it('should return max instead of 0 when the value is a multiple of max', () => {
+			// Act
+			const result = circularize(30, 10);
+
+			// Assert
+			expect(result).toBe(10);
+		});
+
+		it('should keep values already inside the range unchanged', () => {
+			// Act
+			const result = circularize(7, 10);
+
+			// Assert
+			expect(result).toBe(7);
+		});
+
+		it('should wrap values above max', () => {
+			// Act
+			const result = circularize(11, 10);
+
+			// Assert
+			expect(result).toBe(1);
+		});
+
+		it('should wrap negative values', () => {
+			// Act
+			const result = circularize(-1, 10);
+
+			// Assert
+			expect(result).toBe(9);
+		});
+
+		it('should wrap values several turns above max', () => {
+			// Act
+			const result = circularize(25, 10);
+
+			// Assert
+			expect(result).toBe(5);
+		});
+	});
+});