UInt128 Test

1import { describe, expect, it } from "vitest";
2import { query } from "./clickhouse.js";
3import { NeedMoreData, Cursor } from "../src/readers/core.js";
4import { readUInt128 } from "../src/readers/integers.js";
5
6async function reader(expr: string): Promise<Cursor> {
7  return new Cursor(await query(`SELECT ${expr} FORMAT RowBinary`));
8}
9
10const MAX = 340282366920938463463374607431768211455n; // 2^128 - 1
11
12describe("readUInt128", () => {
13  it("decodes 0n", async () => {
14    const r = await reader("toUInt128(0)");
15    expect(readUInt128(r)).toBe(0n);
16    expect(r.pos).toBe(16);
17  });
18
19  // Value in the high word confirms the low/high composition.
20  it("decodes 2^64 (only the high word set)", async () => {
21    expect(readUInt128(await reader("toUInt128('18446744073709551616')"))).toBe(
22      18446744073709551616n,
23    );
24  });
25
26  it("decodes the max (2^128 - 1)", async () => {
27    expect(readUInt128(await reader(`toUInt128('${MAX}')`))).toBe(MAX);
28  });
29
30  describe("advance() edge cases", () => {
31    it("throws NeedMoreData for every incomplete prefix (0 .. full.length-1)", async () => {
32      const full = await query("SELECT toUInt128(5) FORMAT RowBinary");
33      for (let len = 0; len < full.length; len++) {
34        const r = new Cursor(full.subarray(0, len));
35        let thrown: unknown;
36        try {
37          readUInt128(r);
38        } catch (e) {
39          thrown = e;
40        }
41        expect(thrown, `prefix length ${len} of ${full.length}`).toBe(
42          NeedMoreData,
43        );
44      }
45    });
46  });
47});