Merge pull request #261 from yearn/feat/is-zero

feat: Add `isZero` helper

packages/web-lib/utils/isZero.test.ts

@@ -0,0 +1,34 @@
+import {isZero} from '@yearn-finance/web-lib/utils/isZero';
+
+describe('isZero function', (): void => {
+	test('returns false when no argument given', (): void => {
+		expect(isZero()).toBe(false);
+	});
+
+	test.each([
+		[0, true],
+		['0', true],
+		['0.0', true],
+		['0,0', true],
+		['000', true],
+		[0n, true],
+		[`${0}`, true],
+		[' 0 ', true],
+		[' 0.00 ', true],
+		['-0', true],
+		[null, false],
+		[undefined, false],
+		[-1, false],
+		['1', false],
+		[1, false],
+		['-1', false],
+		['0.1', false],
+		[1n, false],
+		['abc', false],
+		[NaN, false],
+		['', false],
+		['  ', false]
+	])('isZero(%p) should return %s', (input, expected): void => {
+		expect(isZero(input)).toBe(expected);
+	});
+});

packages/web-lib/utils/isZero.ts

@@ -0,0 +1,27 @@
+type TProps = bigint | number | string | null;
+
+export function isZero(value?: TProps): boolean {
+	if (value === null || value === undefined) {
+		return false;
+	}
+
+	if (typeof value === "string") {
+		value = value.trim().replace(',', '.');
+
+		if (value === "") {
+			return false;
+		}
+
+		// Check if the string can be parsed as a floating-point number
+		const parsed = Number(value);
+		if (!isNaN(parsed)) {
+			return parsed === 0;
+		}
+	}
+
+	try {
+		return BigInt(value) === 0n;
+	} catch {
+		return false;
+	}
+}