Enum16 Test

1import { describe, expect, it } from "vitest";
2import { query } from "./clickhouse.js";
3import { NeedMoreData, Cursor } from "../src/readers/core.js";
4import { readEnum16 } from "../src/readers/enums.js";
5
6async function reader(expr: string): Promise<Cursor> {
7  return new Cursor(await query(`SELECT ${expr} FORMAT RowBinary`));
8}
9
10describe("readEnum16", () => {
11  it("resolves a 16-bit underlying value to its name", async () => {
12    const read = readEnum16(
13      new Map([
14        [1, "small"],
15        [300, "big"],
16      ]),
17    );
18    const r = await reader("CAST('big' AS Enum16('small' = 1, 'big' = 300))");
19    expect(read(r)).toBe("big");
20    expect(r.pos).toBe(2);
21  });
22
23  it("resolves a negative enum value", async () => {
24    const read = readEnum16(
25      new Map([
26        [-1000, "lo"],
27        [1000, "hi"],
28      ]),
29    );
30    expect(
31      read(await reader("CAST('lo' AS Enum16('lo' = -1000, 'hi' = 1000))")),
32    ).toBe("lo");
33  });
34
35  it("falls back to the stringified integer for an unmapped value", () => {
36    // Wire bytes for Int16 300 (little-endian) with an empty map => "300".
37    expect(readEnum16(new Map())(new Cursor(Buffer.from([0x2c, 0x01])))).toBe(
38      "300",
39    );
40  });
41
42  describe("advance() edge cases", () => {
43    it("throws NeedMoreData for every incomplete prefix (0 .. full.length-1)", async () => {
44      const read = readEnum16(
45        new Map([
46          [1, "small"],
47          [300, "big"],
48        ]),
49      );
50      const full = await query(
51        "SELECT CAST('big' AS Enum16('small' = 1, 'big' = 300)) FORMAT RowBinary",
52      );
53      for (let len = 0; len < full.length; len++) {
54        const r = new Cursor(full.subarray(0, len));
55        let thrown: unknown;
56        try {
57          read(r);
58        } catch (e) {
59          thrown = e;
60        }
61        expect(thrown, `prefix length ${len} of ${full.length}`).toBe(
62          NeedMoreData,
63        );
64      }
65    });
66  });
67});