Int256 Test

1import { describe, expect, it } from "vitest";
2import { query } from "./clickhouse.js";
3import { NeedMoreData, Cursor } from "../src/readers/core.js";
4import { readInt256 } from "../src/readers/integers.js";
5
6async function reader(expr: string): Promise<Cursor> {
7  return new Cursor(await query(`SELECT ${expr} FORMAT RowBinary`));
8}
9
10// 2^255 - 1 and -2^255
11const MAX =
12  57896044618658097711785492504343953926634992332820282019728792003956564819967n;
13const MIN =
14  -57896044618658097711785492504343953926634992332820282019728792003956564819968n;
15
16describe("readInt256", () => {
17  it("decodes 0n", async () => {
18    const r = await reader("toInt256(0)");
19    expect(readInt256(r)).toBe(0n);
20    expect(r.pos).toBe(32);
21  });
22
23  it("decodes -1n (all 0xff, sign spans all four words)", async () => {
24    expect(readInt256(await reader("toInt256('-1')"))).toBe(-1n);
25  });
26
27  it("decodes the max (2^255 - 1)", async () => {
28    expect(readInt256(await reader(`toInt256('${MAX}')`))).toBe(MAX);
29  });
30
31  it("decodes the min (-2^255)", async () => {
32    expect(readInt256(await reader(`toInt256('${MIN}')`))).toBe(MIN);
33  });
34
35  describe("advance() edge cases", () => {
36    it("throws NeedMoreData for every incomplete prefix (0 .. full.length-1)", async () => {
37      const full = await query("SELECT toInt256(-5) FORMAT RowBinary");
38      for (let len = 0; len < full.length; len++) {
39        const r = new Cursor(full.subarray(0, len));
40        let thrown: unknown;
41        try {
42          readInt256(r);
43        } catch (e) {
44          thrown = e;
45        }
46        expect(thrown, `prefix length ${len} of ${full.length}`).toBe(
47          NeedMoreData,
48        );
49      }
50    });
51  });
52});