Fixing bug regarding circular references in deepequal

src/deepEqual.js

@@ -1,38 +1,42 @@
-import get from './get.js';
-import isEqual from './isEqual.js';
-import traverse from './traverse.js';
-
-/**
- * Deeply compares two items.
- *
- * @example
- * ``` javascript
- * import { deepEqual } from 'object-agent';
- *
- * deepEqual(null, undefined);
- * // => false
- *
- * const item1 = {
- *     a: ['b']
- * }
- * const item2 = {
- *     a: ['c']
- * }
- *
- * deepEqual(item1, item2);
- * // => false
- * ```
- *
- * @function deepEqual
- * @category Comparison
- *
- * @arg {*} item1
- * @arg {*} item2
- *
- * @returns {Boolean}
- */
-export default (item1, item2) => {
-	return Object.is(item1, item2) || !traverse(item1, (path, value, isCircular) => {
-		return isCircular && Object.is(value, get(item2, path)) || !isEqual(value, get(item2, path));
-	});
-};
+import get from './get.js';
+import isEqual from './isEqual.js';
+import traverse from './traverse.js';
+
+/**
+ * Deeply compares two items.
+ *
+ * @example
+ * ``` javascript
+ * import { deepEqual } from 'object-agent';
+ *
+ * deepEqual(null, undefined);
+ * // => false
+ *
+ * const item1 = {
+ *     a: ['b']
+ * }
+ * const item2 = {
+ *     a: ['c']
+ * }
+ *
+ * deepEqual(item1, item2);
+ * // => false
+ * ```
+ *
+ * @function deepEqual
+ * @category Comparison
+ *
+ * @arg {*} item1
+ * @arg {*} item2
+ *
+ * @returns {Boolean}
+ */
+export default (item1, item2) => {
+	return Object.is(item1, item2) || !traverse(item1, (path, value, isCircular) => {
+		if (isCircular && Object.is(value, get(item2, path))) {
+			return false;
+		}
+
+		return !isEqual(value, get(item2, path));
+	});
+};

tests/deepEqual.test.js

@@ -1,40 +1,54 @@
-import displayValue from 'display-value';
-import { assert } from 'type-enforcer';
-import { clone, deepEqual } from '../index.js';
-import { testValues } from './testValues.js';
-
-describe('deepEqual', () => {
-	testValues.forEach((value1, index1) => {
-		clone(testValues).forEach((value2, index2) => {
-			if (index1 !== index2) {
-				it(`should return false for ${displayValue(value1)} [${index1}] and ${displayValue(value2)} [${index2}]`, () => {
-					assert.is(deepEqual(value1, value2), false);
-				});
-			}
-			else {
-				it(`should return true for ${displayValue(value1)} [${index1}] and ${displayValue(value2)} [${index2}]`, () => {
-					assert.is(deepEqual(value1, value2), true);
-				});
-			}
-		});
-	});
-
-	it('should compare a circular reference', () => {
-		const object = {
-			key1: 'something',
-			key2: {
-				key3: 'another'
-			}
-		};
-		object.key2.key4 = [object.key2];
-		const object2 = {
-			key1: 'something',
-			key2: {
-				key3: 'another'
-			}
-		};
-		object2.key2.key4 = [object2.key2];
-
-		assert.equal(deepEqual(object, object2), true);
-	});
-});
+import displayValue from 'display-value';
+import { assert } from 'type-enforcer';
+import { clone, deepEqual } from '../index.js';
+import { testValues } from './testValues.js';
+
+describe('deepEqual', () => {
+	testValues.forEach((value1, index1) => {
+		clone(testValues).forEach((value2, index2) => {
+			if (index1 !== index2) {
+				it(`should return false for ${displayValue(value1)} [${index1}] and ${displayValue(value2)} [${index2}]`, () => {
+					assert.is(deepEqual(value1, value2), false);
+				});
+			}
+			else {
+				it(`should return true for ${displayValue(value1)} [${index1}] and ${displayValue(value2)} [${index2}]`, () => {
+					assert.is(deepEqual(value1, value2), true);
+				});
+			}
+		});
+	});
+
+	it('should compare the same item referenced multiple times', () => {
+		const item = {};
+
+		assert.equal(deepEqual([{
+			item
+		}, {
+			item
+		}], [{
+			item
+		}, {
+			item
+		}]), true);
+	});
+
+	it('should compare seperate circular references in different objects', () => {
+		const object = {
+			key1: 'something',
+			key2: {
+				key3: 'another'
+			}
+		};
+		object.key2.key4 = [object.key2];
+		const object2 = {
+			key1: 'something',
+			key2: {
+				key3: 'another'
+			}
+		};
+		object2.key2.key4 = [object2.key2];
+
+		assert.equal(deepEqual(object, object2), true);
+	});
+});