[Refactor] don't attempt to run iterable comparisons when there's no …

…Symbol.iterator.
inspect-js · Dec 10, 2015 · 8e34291 · 8e34291
1 parent 078e64a
commit 8e34291
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Showing 2 changed files with 22 additions and 19 deletions.
diff --git a/.eslintrc b/.eslintrc
@@ -7,6 +7,7 @@
 		"complexity": [1, 10],
 		"eqeqeq": [2, "allow-null"],
 		"id-length": [2, { "min": 1, "max": 23 }],
+		"max-depth": [2, 5],
 		"max-statements": [1, 10],
 		"no-extra-parens": [1],
 		"no-implicit-coercion": [2, {

diff --git a/index.js b/index.js
@@ -138,25 +138,27 @@ module.exports = function isEqual(value, other) {
 		if (value.isPrototypeOf(other) || other.isPrototypeOf(value)) { return false; }
 		if (getPrototypeOf(value) !== getPrototypeOf(other)) { return false; }
 
-		var valueIteratorFn = value[symbolIterator];
-		var valueIsIterable = isCallable(valueIteratorFn);
-		var otherIteratorFn = other[symbolIterator];
-		var otherIsIterable = isCallable(otherIteratorFn);
-		if (valueIsIterable !== otherIsIterable) {
-			return false;
-		}
-		if (valueIsIterable && otherIsIterable) {
-			var valueIterator = valueIteratorFn.call(value);
-			var otherIterator = otherIteratorFn.call(other);
-			var valueNext, otherNext;
-			do {
-				valueNext = valueIterator.next();
-				otherNext = otherIterator.next();
-				if (!valueNext.done && !otherNext.done && !isEqual(valueNext, otherNext)) {
-					return false;
-				}
-			} while (!valueNext.done && !otherNext.done);
-			return valueNext.done === otherNext.done;
+		if (symbolIterator) {
+			var valueIteratorFn = value[symbolIterator];
+			var valueIsIterable = isCallable(valueIteratorFn);
+			var otherIteratorFn = other[symbolIterator];
+			var otherIsIterable = isCallable(otherIteratorFn);
+			if (valueIsIterable !== otherIsIterable) {
+				return false;
+			}
+			if (valueIsIterable && otherIsIterable) {
+				var valueIterator = valueIteratorFn.call(value);
+				var otherIterator = otherIteratorFn.call(other);
+				var valueNext, otherNext;
+				do {
+					valueNext = valueIterator.next();
+					otherNext = otherIterator.next();
+					if (!valueNext.done && !otherNext.done && !isEqual(valueNext, otherNext)) {
+						return false;
+					}
+				} while (!valueNext.done && !otherNext.done);
+				return valueNext.done === otherNext.done;
+			}
 		}
 
 		return isEqual(entries(value), entries(other));