Consolidates asserts#equal branches for keyed collections (Map/Set) and supports deep equality of Map keys

std/testing/asserts.ts

@@ -67,33 +67,13 @@ function buildMessage(diffResult: ReadonlyArray<DiffResult<string>>): string[] {
  return messages;
 }
 
+function isKeyedCollection(x: unknown): x is Set<unknown> {
+ return [Symbol.iterator, "size"].every(k => k in (x as Set<unknown>));
+}
+
 export function equal(c: unknown, d: unknown): boolean {
  const seen = new Map();
  return (function compare(a: unknown, b: unknown): boolean {
- if (a && a instanceof Set && b && b instanceof Set) {
- if (a.size !== b.size) {
- return false;
- }
- for (const item of b) {
- if (!a.has(item)) {
- return false;
- }
- }
- return true;
- }
- if (a && b && a instanceof Map && b instanceof Map) {
- if (a.size !== b.size) {
- return false;
- }
-
- for (const [key, value] of a) {
- if (!compare(value, b.get(key))) {
- return false;
- }
- }
-
- return true;
- }
  // Have to render RegExp & Date for string comparison
  // unless it's mistreated as object
  if (
@@ -114,6 +94,28 @@ export function equal(c: unknown, d: unknown): boolean {
  if (Object.keys(a || {}).length !== Object.keys(b || {}).length) {
  return false;
  }
+ 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--;
+ }
+ }
+ }
+
+ return unmatchedEntries === 0;
+ }
  const merged = { ...a, ...b };
  for (const key in merged) {
  type Key = keyof typeof merged;

std/testing/asserts_test.ts

@@ -44,6 +44,7 @@ test(function testingEqual(): void {
  assert(equal(new Set([1]), new Set([1])));
  assert(!equal(new Set([1]), new Set([2])));
  assert(equal(new Set([1, 2, 3]), new Set([3, 2, 1])));
+ assert(equal(new Set([1, new Set([2, 3])]), new Set([new Set([3, 2]), 1])));
  assert(!equal(new Set([1, 2]), new Set([3, 2, 1])));
  assert(!equal(new Set([1, 2, 3]), new Set([4, 5, 6])));
  assert(equal(new Set("denosaurus"), new Set("denosaurussss")));
@@ -83,6 +84,16 @@ test(function testingEqual(): void {
  new Map([["foo", new Map([["bar", "qux"]])]])
  )
  );
+ assert(equal(new Map([[{ x: 1 }, true]]), new Map([[{ x: 1 }, true]])));
+ assert(!equal(new Map([[{ x: 1 }, true]]), new Map([[{ x: 1 }, false]])));
+ assert(!equal(new Map([[{ x: 1 }, true]]), new Map([[{ x: 2 }, true]])));
+ assert(equal([1, 2, 3], [1, 2, 3]));
+ assert(equal([1, [2, 3]], [1, [2, 3]]));
+ assert(!equal([1, 2, 3, 4], [1, 2, 3]));
+ assert(!equal([1, 2, 3, 4], [1, 2, 3]));
+ assert(!equal([1, 2, 3, 4], [1, 4, 2, 3]));
+ assert(equal(new Uint8Array([1, 2, 3, 4]), new Uint8Array([1, 2, 3, 4])));
+ assert(!equal(new Uint8Array([1, 2, 3, 4]), new Uint8Array([2, 1, 4, 3])));
 });
 
 test(function testingNotEquals(): void {