Testing refactor (denoland/deno_std#240)

Original: https://github.com/denoland/deno_std/commit/e1d5c00279132aa639030c6c6d9b4e308bd4775e

1 files changed, 33 insertions, 2 deletions

diff --git a/testing/asserts.ts b/testing/asserts.ts
index a2110b8d9..8932793d4 100644
--- a/testing/asserts.ts
+++ b/testing/asserts.ts
@@ -1,11 +1,38 @@
 // Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
-import { assertEqual as prettyAssertEqual } from "./pretty.ts";
+import { assertEq as prettyAssertEqual } from "./pretty.ts";
 
 interface Constructor {
   // eslint-disable-next-line @typescript-eslint/no-explicit-any
   new (...args: any[]): any;
 }
 
+export function equal(c: unknown, d: unknown): boolean {
+  const seen = new Map();
+  return (function compare(a: unknown, b: unknown) {
+    if (Object.is(a, b)) {
+      return true;
+    }
+    if (a && typeof a === "object" && b && typeof b === "object") {
+      if (seen.get(a) === b) {
+        return true;
+      }
+      if (Object.keys(a || {}).length !== Object.keys(b || {}).length) {
+        return false;
+      }
+      const merged = { ...a, ...b };
+      for (const key in merged) {
+        type Key = keyof typeof merged;
+        if (!compare(a && a[key as Key], b && b[key as Key])) {
+          return false;
+        }
+      }
+      seen.set(a, b);
+      return true;
+    }
+    return false;
+  })(c, d);
+}
+
 /** Make an assertion, if not `true`, then throw. */
 export function assert(expr: boolean, msg = ""): void {
   if (!expr) {
@@ -17,7 +44,11 @@ export function assert(expr: boolean, msg = ""): void {
  * Make an assertion that `actual` and `expected` are equal, deeply. If not
  * deeply equal, then throw.
  */
-export function equal(actual: unknown, expected: unknown, msg?: string): void {
+export function assertEq(
+  actual: unknown,
+  expected: unknown,
+  msg?: string
+): void {
   prettyAssertEqual(actual, expected, msg);
 }