bun-sqlite/src/lib/schema/order-db-schema.test.ts

import { describe, expect, test } from "bun:test";
import type { BUN_SQLITE_TableSchemaType } from "../../types";
import orderDBSchema from "./order-db-schema";

function table({
    name,
    refs = [],
}: {
    name: string;
    refs?: string[];
}): BUN_SQLITE_TableSchemaType {
    return {
        tableName: name,
        fields: refs.map((ref) => ({
            fieldName: `${ref}_id`,
            dataType: "INTEGER",
            foreignKey: {
                destinationTableName: ref,
                destinationTableColumnName: "id",
            },
        })),
    };
}

function order(tables: BUN_SQLITE_TableSchemaType[]) {
    const res = orderDBSchema({ db_schema: { tables } });
    return res.tables.map((t) => t.tableName);
}

describe("orderDBSchema", () => {
    test("places parents before children", () => {
        expect(
            order([
                table({ name: "comments", refs: ["posts", "users"] }),
                table({ name: "posts", refs: ["users"] }),
                table({ name: "users" }),
            ]),
        ).toEqual(["users", "posts", "comments"]);
    });

    test("keeps declaration order when there are no dependencies", () => {
        expect(
            order([table({ name: "b" }), table({ name: "a" })]),
        ).toEqual(["b", "a"]);
    });

    test("handles self references without recursing forever", () => {
        expect(
            order([
                table({ name: "categories", refs: ["categories"] }),
                table({ name: "comments", refs: ["comments", "users"] }),
                table({ name: "users" }),
            ]),
        ).toEqual(["categories", "users", "comments"]);
    });

    test("handles cycles and emits each table once", () => {
        const res = order([
            table({ name: "a", refs: ["b"] }),
            table({ name: "b", refs: ["a"] }),
            table({ name: "c", refs: ["a"] }),
        ]);
        expect(res).toHaveLength(3);
        expect(new Set(res).size).toBe(3);
        expect(res.indexOf("c")).toBeGreaterThan(res.indexOf("a"));
    });

    test("ignores references to tables outside the schema", () => {
        expect(
            order([table({ name: "posts", refs: ["external_users"] })]),
        ).toEqual(["posts"]);
    });
});