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std/assert/equal.ts

Deno standard library
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// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.function isKeyedCollection(x: unknown): x is Set<unknown> { return [Symbol.iterator, "size"].every((k) => k in (x as Set<unknown>));}
function constructorsEqual(a: object, b: object) { return a.constructor === b.constructor || a.constructor === Object && !b.constructor || !a.constructor && b.constructor === Object;}
/** * Deep equality comparison used in assertions * @param c actual value * @param d expected value */export function equal(c: unknown, d: unknown): boolean { const seen = new Map(); return (function compare(a: unknown, b: unknown): boolean { // Have to render RegExp & Date for string comparison // unless it's mistreated as object if ( a && b && ((a instanceof RegExp && b instanceof RegExp) || (a instanceof URL && b instanceof URL)) ) { return String(a) === String(b); } if (a instanceof Date && b instanceof Date) { const aTime = a.getTime(); const bTime = b.getTime(); // Check for NaN equality manually since NaN is not // equal to itself. if (Number.isNaN(aTime) && Number.isNaN(bTime)) { return true; } return aTime === bTime; } if (typeof a === "number" && typeof b === "number") { return Number.isNaN(a) && Number.isNaN(b) || a === b; } if (Object.is(a, b)) { return true; } if (a && typeof a === "object" && b && typeof b === "object") { if (a && b && !constructorsEqual(a, b)) { return false; } if (a instanceof WeakMap || b instanceof WeakMap) { if (!(a instanceof WeakMap && b instanceof WeakMap)) return false; throw new TypeError("cannot compare WeakMap instances"); } if (a instanceof WeakSet || b instanceof WeakSet) { if (!(a instanceof WeakSet && b instanceof WeakSet)) return false; throw new TypeError("cannot compare WeakSet instances"); } if (seen.get(a) === b) { return true; } if (Object.keys(a || {}).length !== Object.keys(b || {}).length) { return false; } seen.set(a, b); if (isKeyedCollection(a) && isKeyedCollection(b)) { if (a.size !== b.size) { return false; }
let unmatchedEntries = a.size;
for (const [aKey, aValue] of a.entries()) { for (const [bKey, bValue] of b.entries()) { /* Given that Map keys can be references, we need * to ensure that they are also deeply equal */ if ( (aKey === aValue && bKey === bValue && compare(aKey, bKey)) || (compare(aKey, bKey) && compare(aValue, bValue)) ) { unmatchedEntries--; break; } } }
return unmatchedEntries === 0; } const merged = { ...a, ...b }; for ( const key of [ ...Object.getOwnPropertyNames(merged), ...Object.getOwnPropertySymbols(merged), ] ) { type Key = keyof typeof merged; if (!compare(a && a[key as Key], b && b[key as Key])) { return false; } if (((key in a) && (!(key in b))) || ((key in b) && (!(key in a)))) { return false; } } if (a instanceof WeakRef || b instanceof WeakRef) { if (!(a instanceof WeakRef && b instanceof WeakRef)) return false; return compare(a.deref(), b.deref()); } return true; } return false; })(c, d);}