Support Sets in asserts.equals (denoland/deno_std#350)

Original: https://github.com/denoland/deno_std/commit/9432d703291f74b230f39b30614d57a5623faa59

2 files changed, 17 insertions, 0 deletions

diff --git a/testing/asserts.ts b/testing/asserts.ts
index eb5e11969..83fa7c8e5 100644
--- a/testing/asserts.ts
+++ b/testing/asserts.ts
@@ -16,6 +16,17 @@ export class AssertionError extends Error {
 export function equal(c: unknown, d: unknown): boolean {
   const seen = new Map();
   return (function compare(a: unknown, b: unknown) {
+    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;
+    }
     // Have to render RegExp & Date for string comparison
     // unless it's mistreated as object
     if (
diff --git a/testing/asserts_test.ts b/testing/asserts_test.ts
index 87e0335ac..ed58d74df 100644
--- a/testing/asserts_test.ts
+++ b/testing/asserts_test.ts
@@ -40,6 +40,12 @@ test(function testingEqual() {
   assert(!equal(/deno/, /node/));
   assert(equal(new Date(2019, 0, 3), new Date(2019, 0, 3)));
   assert(!equal(new Date(2019, 0, 3), new Date(2019, 1, 3)));
+  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, 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")));
 });
 
 test(function testingNotEquals() {