Geometry Test

1import { describe, expect, it } from "vitest";
2import { query } from "./clickhouse.js";
3import { NeedMoreData, Cursor } from "../src/readers/core.js";
4import { readGeometry } from "../src/readers/geo.js";
5
6// Geometry's variant has "similar" alternatives (LineString/Ring), so the type
7// needs allow_suspicious_variant_types; the value still casts through a geo type.
8async function reader(expr: string): Promise<Cursor> {
9  return new Cursor(
10    await query(
11      `SELECT ${expr} SETTINGS allow_suspicious_variant_types = 1 FORMAT RowBinary`,
12    ),
13  );
14}
15
16describe("readGeometry", () => {
17  it("decodes a Point (discriminant 3)", async () => {
18    const r = await reader("CAST(CAST((1.5, 2.5) AS Point) AS Geometry)");
19    expect(readGeometry(r)).toEqual([1.5, 2.5]);
20  });
21
22  it("decodes a LineString (discriminant 0)", async () => {
23    const r = await reader(
24      "CAST(CAST([(0, 0), (1, 2)] AS LineString) AS Geometry)",
25    );
26    expect(readGeometry(r)).toEqual([
27      [0, 0],
28      [1, 2],
29    ]);
30  });
31
32  it("decodes a MultiPolygon (discriminant 2)", async () => {
33    const r = await reader(
34      "CAST(CAST([[[(0, 0), (1, 0), (1, 1)]]] AS MultiPolygon) AS Geometry)",
35    );
36    expect(readGeometry(r)).toEqual([
37      [
38        [
39          [0, 0],
40          [1, 0],
41          [1, 1],
42        ],
43      ],
44    ]);
45  });
46
47  describe("advance() edge cases", () => {
48    it("throws NeedMoreData for every incomplete prefix (0 .. full.length-1)", async () => {
49      const full = await query(
50        "SELECT CAST(CAST((1.5, 2.5) AS Point) AS Geometry) SETTINGS allow_suspicious_variant_types = 1 FORMAT RowBinary",
51      );
52      for (let len = 0; len < full.length; len++) {
53        const r = new Cursor(full.subarray(0, len));
54        let thrown: unknown;
55        try {
56          readGeometry(r);
57        } catch (e) {
58          thrown = e;
59        }
60        expect(thrown, `prefix length ${len} of ${full.length}`).toBe(
61          NeedMoreData,
62        );
63      }
64    });
65  });
66});