All files / src/internal/shared clone.js

97.43% Statements 114/117
89.18% Branches 33/37
100% Functions 2/2
97.36% Lines 111/114

Press n or j to go to the next uncovered block, b, p or k for the previous block.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 1152x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 107x 23x 23x 23x 23x 23x 1x 1x 23x 2x 2x 2x 2x 2x 2x 2x 2x 2x 23x 23x 23x 84x 84x 84x 2x 2x 2x 2x 2x 2x 2x 2x 2x 443x 443x 198x 198x 193x 198x 198x 184x 198x 127x 127x 127x 127x 279x 279x 127x 127x 127x 57x 198x 47x 47x 47x 47x 47x 56x 56x 56x 47x 47x 47x 10x 194x 2x 2x 8x 194x 1x 1x 1x 1x 1x 1x 1x 198x 252x 443x       252x 252x 252x 443x 113x 113x 113x 113x 113x 113x 443x  
/** @import { Snapshot } from './types' */
import { DEV } from 'esm-env';
import * as w from './warnings.js';
import { get_prototype_of, is_array, object_prototype } from './utils.js';
 
/**
 * In dev, we keep track of which properties could not be cloned. In prod
 * we don't bother, but we keep a dummy array around so that the
 * signature stays the same
 * @type {string[]}
 */
const empty = [];
 
/**
 * @template T
 * @param {T} value
 * @param {boolean} [skip_warning]
 * @returns {Snapshot<T>}
 */
export function snapshot(value, skip_warning = false) {
	if (DEV && !skip_warning) {
		/** @type {string[]} */
		const paths = [];
 
		const copy = clone(value, new Map(), '', paths);
		if (paths.length === 1 && paths[0] === '') {
			// value could not be cloned
			w.state_snapshot_uncloneable();
		} else if (paths.length > 0) {
			// some properties could not be cloned
			const slice = paths.length > 10 ? paths.slice(0, 7) : paths.slice(0, 10);
			const excess = paths.length - slice.length;
 
			let uncloned = slice.map((path) => `- <value>${path}`).join('\n');
			if (excess > 0) uncloned += `\n- ...and ${excess} more`;
 
			w.state_snapshot_uncloneable(uncloned);
		}
 
		return copy;
	}
 
	return clone(value, new Map(), '', empty);
}
 
/**
 * @template T
 * @param {T} value
 * @param {Map<T, Snapshot<T>>} cloned
 * @param {string} path
 * @param {string[]} paths
 * @returns {Snapshot<T>}
 */
function clone(value, cloned, path, paths) {
	if (typeof value === 'object' && value !== null) {
		const unwrapped = cloned.get(value);
		if (unwrapped !== undefined) return unwrapped;
 
		if (value instanceof Map) return /** @type {Snapshot<T>} */ (new Map(value));
		if (value instanceof Set) return /** @type {Snapshot<T>} */ (new Set(value));
 
		if (is_array(value)) {
			const copy = /** @type {Snapshot<any>} */ ([]);
			cloned.set(value, copy);
 
			for (let i = 0; i < value.length; i += 1) {
				copy.push(clone(value[i], cloned, DEV ? `${path}[${i}]` : path, paths));
			}
 
			return copy;
		}
 
		if (get_prototype_of(value) === object_prototype) {
			/** @type {Snapshot<any>} */
			const copy = {};
			cloned.set(value, copy);
 
			for (var key in value) {
				// @ts-expect-error
				copy[key] = clone(value[key], cloned, DEV ? `${path}.${key}` : path, paths);
			}
 
			return copy;
		}
 
		if (value instanceof Date) {
			return /** @type {Snapshot<T>} */ (structuredClone(value));
		}
 
		if (typeof (/** @type {T & { toJSON?: any } } */ (value).toJSON) === 'function') {
			return clone(
				/** @type {T & { toJSON(): any } } */ (value).toJSON(),
				cloned,
				DEV ? `${path}.toJSON()` : path,
				paths
			);
		}
	}
 
	if (value instanceof EventTarget) {
		// can't be cloned
		return /** @type {Snapshot<T>} */ (value);
	}
 
	try {
		return /** @type {Snapshot<T>} */ (structuredClone(value));
	} catch (e) {
		if (DEV) {
			paths.push(path);
		}
 
		return /** @type {Snapshot<T>} */ (value);
	}
}