Check object keys in isEqual

lib/utils/under-dash.js

@@ -55,6 +55,7 @@ const _ = {
     const bType = typeof b;
     const aArray = Array.isArray(a);
     const bArray = Array.isArray(b);
+    let keys;
 
     if (aType !== bType) {
       return false;
@@ -73,6 +74,24 @@ const _ = {
           }
           return false;
         }
+
+        if (a === null || b === null) {
+          return a === b;
+        }
+
+        // Compare object keys and values
+        keys = Object.keys(a);
+
+        if (Object.keys(b).length !== keys.length) {
+          return false;
+        }
+
+        for (const key of keys) {
+          if (!b.hasOwnProperty(key)) {
+            return false;
+          }
+        }
+
         return _.every(a, (aValue, key) => {
           const bValue = b[key];
           return _.isEqual(aValue, bValue);

spec/unit/utils/under-dash.spec.js

@@ -0,0 +1,79 @@
+const _ = verquire('utils/under-dash');
+const util = require('util');
+
+describe('under-dash', () => {
+  describe('isEqual', () => {
+    const values = [
+      0,
+      1,
+      true,
+      false,
+      'string',
+      'foobar',
+      'other string',
+      [],
+      ['array'],
+      ['array', 'foobar'],
+      ['array2'],
+      ['array2', 'foobar'],
+      {},
+      {object: 1},
+      {object: 2},
+      {object: 1, foobar: 'quux'},
+      {object: 2, foobar: 'quux'},
+      null,
+      undefined,
+      () => {},
+      () => {},
+      Symbol('foo'),
+      Symbol('foo'),
+      Symbol('bar'),
+    ];
+
+    function showVal(o) {
+      return util.inspect(o, {compact: true});
+    }
+
+    it('works on simple values', () => {
+      for (let i = 0; i < values.length; i++) {
+        for (let j = 0; j < values.length; j++) {
+          const a = values[i];
+          const b = values[j];
+
+          const assertion = `${showVal(a)} ${i === j ? '==' : '!='} ${showVal(
+            b
+          )}`;
+          expect(_.isEqual(a, b)).to.equal(i === j, `expected ${assertion}`);
+        }
+      }
+    });
+
+    it('works on complex arrays', () => {
+      for (let i = 0; i < values.length; i++) {
+        for (let j = 0; j < values.length; j++) {
+          const a = [values[i]];
+          const b = [values[j]];
+
+          const assertion = `${showVal(a)} ${i === j ? '==' : '!='} ${showVal(
+            b
+          )}`;
+          expect(_.isEqual(a, b)).to.equal(i === j, `expected ${assertion}`);
+        }
+      }
+    });
+
+    it('works on complex objects', () => {
+      for (let i = 0; i < values.length; i++) {
+        for (let j = 0; j < values.length; j++) {
+          const a = {key: values[i]};
+          const b = {key: values[j]};
+
+          const assertion = `${showVal(a)} ${i === j ? '==' : '!='} ${showVal(
+            b
+          )}`;
+          expect(_.isEqual(a, b)).to.equal(i === j, `expected ${assertion}`);
+        }
+      }
+    });
+  });
+});