ladybird/Libraries/LibJS/Tests/builtins/BigInt/BigInt.asUintN.js
Jess 12cbefbee7 LibJS+LibCrypto: Use a bitwise approach for BigInt's as*IntN methods
This speeds up expressions such as `BigInt.asIntN(0x4000000000000, 1n)`
(#3615). And those involving very large bigints.
2025-03-20 09:44:12 +01:00

93 lines
3.7 KiB
JavaScript

describe("errors", () => {
test("invalid index", () => {
expect(() => {
BigInt.asUintN(-1, 0n);
}).toThrowWithMessage(RangeError, "Index must be a positive integer");
expect(() => {
BigInt.asUintN(Symbol(), 0n);
}).toThrowWithMessage(TypeError, "Cannot convert symbol to number");
});
test("invalid BigInt", () => {
expect(() => {
BigInt.asUintN(1, 1);
}).toThrowWithMessage(TypeError, "Cannot convert number to BigInt");
expect(() => {
BigInt.asUintN(1, Symbol());
}).toThrowWithMessage(TypeError, "Cannot convert symbol to BigInt");
expect(() => {
BigInt.asUintN(1, "foo");
}).toThrowWithMessage(SyntaxError, "Invalid value for BigInt: foo");
});
});
describe("correct behavior", () => {
test("basic functionality", () => {
expect(BigInt.asUintN(0, -2n)).toBe(0n);
expect(BigInt.asUintN(0, -1n)).toBe(0n);
expect(BigInt.asUintN(0, 0n)).toBe(0n);
expect(BigInt.asUintN(0, 1n)).toBe(0n);
expect(BigInt.asUintN(0, 2n)).toBe(0n);
expect(BigInt.asUintN(1, -3n)).toBe(1n);
expect(BigInt.asUintN(1, -2n)).toBe(0n);
expect(BigInt.asUintN(1, -1n)).toBe(1n);
expect(BigInt.asUintN(1, 0n)).toBe(0n);
expect(BigInt.asUintN(1, 1n)).toBe(1n);
expect(BigInt.asUintN(1, 2n)).toBe(0n);
expect(BigInt.asUintN(1, 3n)).toBe(1n);
expect(BigInt.asUintN(2, -3n)).toBe(1n);
expect(BigInt.asUintN(2, -2n)).toBe(2n);
expect(BigInt.asUintN(2, -1n)).toBe(3n);
expect(BigInt.asUintN(2, 0n)).toBe(0n);
expect(BigInt.asUintN(2, 1n)).toBe(1n);
expect(BigInt.asUintN(2, 2n)).toBe(2n);
expect(BigInt.asUintN(2, 3n)).toBe(3n);
expect(BigInt.asUintN(4, -3n)).toBe(13n);
expect(BigInt.asUintN(4, -2n)).toBe(14n);
expect(BigInt.asUintN(4, -1n)).toBe(15n);
expect(BigInt.asUintN(4, 0n)).toBe(0n);
expect(BigInt.asUintN(4, 1n)).toBe(1n);
expect(BigInt.asUintN(4, 2n)).toBe(2n);
expect(BigInt.asUintN(4, 3n)).toBe(3n);
const extremelyBigInt = 123456789123456789123456789123456789123456789123456789n;
expect(BigInt.asUintN(0, extremelyBigInt)).toBe(0n);
expect(BigInt.asUintN(1, extremelyBigInt)).toBe(1n);
expect(BigInt.asUintN(2, extremelyBigInt)).toBe(1n);
expect(BigInt.asUintN(4, extremelyBigInt)).toBe(5n);
expect(BigInt.asUintN(128, extremelyBigInt)).toBe(241220992521549204068304577237384191765n);
expect(BigInt.asUintN(256, extremelyBigInt)).toBe(extremelyBigInt);
expect(BigInt.asUintN(0, -extremelyBigInt)).toBe(0n);
expect(BigInt.asUintN(1, -extremelyBigInt)).toBe(1n);
expect(BigInt.asUintN(2, -extremelyBigInt)).toBe(3n);
expect(BigInt.asUintN(4, -extremelyBigInt)).toBe(11n);
expect(BigInt.asUintN(128, -extremelyBigInt)).toBe(99061374399389259395070030194384019691n);
expect(BigInt.asUintN(256, -extremelyBigInt)).toBe(
115792089237316195423570861551898784396480861208851440582668460551124006183147n
);
});
test("large bit values", () => {
const INDEX_MAX = 2 ** 53 - 1;
const LAST_8_DIGITS = 10n ** 8n;
expect(BigInt.asUintN(0x400000000, 1n)).toBe(1n);
expect(BigInt.asUintN(0x4000, -1n) % LAST_8_DIGITS).toBe(64066815n);
expect(BigInt.asUintN(0x400000000, 2n)).toBe(2n);
expect(BigInt.asUintN(0x4000, -2n) % LAST_8_DIGITS).toBe(64066814n);
expect(BigInt.asUintN(INDEX_MAX, 2n)).toBe(2n);
expect(() => {
BigInt.asUintN(INDEX_MAX, -2n);
}).toThrowWithMessage(InternalError, "Out of memory");
});
});