svelte-kit-vice/src/arts/sium/test/introspect.test.ts

import { describe, expect, it } from 'vitest';
import {
	array,
	lazy,
	number,
	object,
	optional,
	pipe,
	serializeSchema,
	string,
	walkSchema
} from '../core';
import type { Schema } from '../core';

describe('serializeSchema()', () => {
	it('serializes object schemas into a JSON-friendly tree', () => {
		const schema = object({ a: string() });

		expect(serializeSchema(schema)).toEqual({
			kind: 'object',
			wrappers: [],
			effects: [],
			async: false,
			meta: {},
			shape: {
				kind: 'object',
				unknownKeys: 'strip',
				fields: {
					a: {
						kind: 'string',
						wrappers: [],
						effects: [],
						async: false,
						meta: {}
					}
				}
			}
		});
	});

	it('truncates recursive schemas without overflowing', () => {
		type TreeNode = {
			value: string;
			children?: TreeNode[];
		};

		const TreeSchema: Schema<TreeNode, TreeNode> = lazy(() =>
			object({
				value: string(),
				children: optional(array(TreeSchema))
			})
		);

		const serialized = serializeSchema(TreeSchema, 1);
		const children =
			serialized.shape?.kind === 'object' ? serialized.shape.fields.children : undefined;

		expect(children?.shape).toEqual({
			kind: 'truncated',
			inner: 'optional'
		});
	});
});

describe('countLeafFields()', () => {
	it('counts nested object leaves and treats arrays as one slot', async () => {
		const { countLeafFields } = await import('../core');

		expect(
			countLeafFields(
				object({
					a: string(),
					b: number(),
					nested: object({
						c: string()
					})
				})
			)
		).toBe(3);

		expect(countLeafFields(array(string()))).toBe(1);
	});
});

describe('walkSchema()', () => {
	it('visits the schema tree in pre-order for object fields', () => {
		const visited: string[] = [];
		const schema = object({
			a: string(),
			b: pipe(number())
		});

		walkSchema(schema, (_node, path) => {
			visited.push(path.length === 0 ? '(root)' : path.join('.'));
		});

		expect(visited).toEqual(['(root)', 'a', 'b']);
	});
});