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import assert from "assert";import { encode, decode, ExtensionCodec, DecodeError } from "../src";
// There's a built-in `useBigInt64: true` option, but a custom codec might be// better if you'd like to encode bigint to reduce the size of binaries.
const BIGINT_EXT_TYPE = 0; // Any in 0-127
const extensionCodec = new ExtensionCodec();extensionCodec.register({  type: BIGINT_EXT_TYPE,  encode(input: unknown): Uint8Array | null {    if (typeof input === "bigint") {      if (input <= Number.MAX_SAFE_INTEGER && input >= Number.MIN_SAFE_INTEGER) {        return encode(Number(input));      } else {        return encode(String(input));      }    } else {      return null;    }  },  decode(data: Uint8Array): bigint {    const val = decode(data);    if (!(typeof val === "string" || typeof val === "number")) {      throw new DecodeError(`unexpected BigInt source: ${val} (${typeof val})`);    }    return BigInt(val);  },});
describe("codec BigInt", () => {  it("encodes and decodes 0n", () => {    const value = BigInt(0);    const encoded = encode(value, { extensionCodec });    assert.deepStrictEqual(decode(encoded, { extensionCodec }), value);  });
  it("encodes and decodes 100n", () => {    const value = BigInt(100);    const encoded = encode(value, { extensionCodec });    assert.deepStrictEqual(decode(encoded, { extensionCodec }), value);  });
  it("encodes and decodes -100n", () => {    const value = BigInt(-100);    const encoded = encode(value, { extensionCodec });    assert.deepStrictEqual(decode(encoded, { extensionCodec }), value);  });
  it("encodes and decodes MAX_SAFE_INTEGER+1", () => {    const value = BigInt(Number.MAX_SAFE_INTEGER) + BigInt(1);    const encoded = encode(value, { extensionCodec });    assert.deepStrictEqual(decode(encoded, { extensionCodec }), value);  });
  it("encodes and decodes MIN_SAFE_INTEGER-1", () => {    const value = BigInt(Number.MIN_SAFE_INTEGER) - BigInt(1);    const encoded = encode(value, { extensionCodec });    assert.deepStrictEqual(decode(encoded, { extensionCodec }), value);  });});