Int128 Test

1import { describe, expect, it } from "vitest";
2import { query } from "./clickhouse.js";
3import { NeedMoreData, Cursor } from "../src/readers/core.js";
4import { readInt128 } from "../src/readers/integers.js";
5
6async function reader(expr: string): Promise<Cursor> {
7  return new Cursor(await query(`SELECT ${expr} FORMAT RowBinary`));
8}
9
10const MAX = 170141183460469231731687303715884105727n; // 2^127 - 1
11const MIN = -170141183460469231731687303715884105728n; // -2^127
12
13describe("readInt128", () => {
14  it("decodes 0n", async () => {
15    const r = await reader("toInt128(0)");
16    expect(readInt128(r)).toBe(0n);
17    expect(r.pos).toBe(16);
18  });
19
20  it("decodes -1n (all 0xff, sign spans both words)", async () => {
21    expect(readInt128(await reader("toInt128('-1')"))).toBe(-1n);
22  });
23
24  it("decodes the max (2^127 - 1)", async () => {
25    expect(readInt128(await reader(`toInt128('${MAX}')`))).toBe(MAX);
26  });
27
28  it("decodes the min (-2^127)", async () => {
29    expect(readInt128(await reader(`toInt128('${MIN}')`))).toBe(MIN);
30  });
31
32  describe("advance() edge cases", () => {
33    it("throws NeedMoreData for every incomplete prefix (0 .. full.length-1)", async () => {
34      const full = await query("SELECT toInt128(-5) FORMAT RowBinary");
35      for (let len = 0; len < full.length; len++) {
36        const r = new Cursor(full.subarray(0, len));
37        let thrown: unknown;
38        try {
39          readInt128(r);
40        } catch (e) {
41          thrown = e;
42        }
43        expect(thrown, `prefix length ${len} of ${full.length}`).toBe(
44          NeedMoreData,
45        );
46      }
47    });
48  });
49});