UUIDHi Lo Test

1import { describe, expect, it } from "vitest";
2import { query } from "./clickhouse.js";
3import { NeedMoreData, Cursor } from "../src/readers/core.js";
4import {
5  formatUUID,
6  readUUID,
7  readUUIDBigInt,
8  readUUIDHiLo,
9} from "../src/readers/uuid.js";
10
11async function reader(expr: string): Promise<Cursor> {
12  return new Cursor(await query(`SELECT ${expr} FORMAT RowBinary`));
13}
14
15describe("readUUIDHiLo", () => {
16  it("returns the two little-endian UInt64 halves [hi, lo]", async () => {
17    const r = await reader("toUUID('61f0c404-5cb3-11e7-907b-a6006ad3dba0')");
18    expect(readUUIDHiLo(r)).toEqual([0x61f0c4045cb311e7n, 0x907ba6006ad3dba0n]);
19    expect(r.pos).toBe(16);
20  });
21
22  it("composes back to the same value as readUUIDBigInt / formatUUID", async () => {
23    const expr = "toUUID('61f0c404-5cb3-11e7-907b-a6006ad3dba0')";
24    const [hi, lo] = readUUIDHiLo(await reader(expr));
25    // hi << 64 | lo is exactly what readUUIDBigInt returns.
26    expect((hi << 64n) | lo).toBe(readUUIDBigInt(await reader(expr)));
27    // The 32 hex digits are hi then lo, zero-padded — matching formatUUID.
28    const hex =
29      hi.toString(16).padStart(16, "0") + lo.toString(16).padStart(16, "0");
30    expect(hex).toBe(
31      formatUUID(readUUID(await reader(expr))).replaceAll("-", ""),
32    );
33  });
34
35  it("decodes the nil UUID as [0, 0]", async () => {
36    const r = await reader("toUUID('00000000-0000-0000-0000-000000000000')");
37    expect(readUUIDHiLo(r)).toEqual([0n, 0n]);
38  });
39
40  describe("advance() edge cases", () => {
41    it("throws NeedMoreData for every incomplete prefix (0 .. full.length-1)", async () => {
42      const full = await query(
43        "SELECT toUUID('61f0c404-5cb3-11e7-907b-a6006ad3dba0') FORMAT RowBinary",
44      );
45      for (let len = 0; len < full.length; len++) {
46        const r = new Cursor(full.subarray(0, len));
47        let thrown: unknown;
48        try {
49          readUUIDHiLo(r);
50        } catch (e) {
51          thrown = e;
52        }
53        expect(thrown, `prefix length ${len} of ${full.length}`).toBe(
54          NeedMoreData,
55        );
56      }
57    });
58  });
59});