[Fix] still check own properties on Dates, RegExps, and Functions

.eslintrc

@@ -9,6 +9,7 @@
 		"func-names": 0,
 		"id-length": [2, { "min": 1, "max": 23 }],
 		"max-depth": [2, 5],
+		"max-len": 0,
 		"max-lines-per-function": [2, { "max": 250 }],
 		"max-statements": [1, 10],
 		"max-statements-per-line": [2, { "max": 2 }],

package.json

@@ -69,6 +69,7 @@
 		"foreach": "^2.0.5",
 		"make-arrow-function": "~1.1.0",
 		"nyc": "^10.3.2",
+		"object.assign": "^4.1.2",
 		"safe-publish-latest": "^2.0.0",
 		"tape": "^5.3.2"
 	},

test/why.js

@@ -12,6 +12,7 @@ var functionsHaveNames = require('functions-have-names')();
 var inspect = require('object-inspect');
 var v = require('es-value-fixtures');
 var hasGeneratorSupport = v.generatorFunctions.length > 0;
+var assign = require('object.assign');
 
 var symbolIterator = (hasSymbols || hasSymbolShams) && Symbol.iterator;
 var symbolToStringTag = (hasSymbols || hasSymbolShams) && Symbol.toStringTag;
@@ -234,6 +235,14 @@ test('dates', function (t) {
 		st.end();
 	});
 
+	var zero = new Date(0);
+	var zeroPlus = assign(new Date(0), { a: 1 });
+	t.equal(
+		isEqualWhy(zero, zeroPlus),
+		'second argument has key "a"; first does not',
+		inspect(zero) + ' and ' + inspect(zeroPlus) + ' are not equal'
+	);
+
 	t.end();
 });
 
@@ -294,6 +303,14 @@ test('regexes', function (t) {
 		st.end();
 	});
 
+	var re = /a/g;
+	var rePlus = assign(/a/g, { a: 1 });
+	t.equal(
+		isEqualWhy(re, rePlus),
+		'second argument has key "a"; first does not',
+		inspect(re) + ' and ' + inspect(rePlus) + ' are not equal'
+	);
+
 	t.end();
 });
 
@@ -519,13 +536,11 @@ test('functions', function (t) {
 	var g = Object(function g() { /* SOME STUFF */ return 1; });
 	var anon1 = Object(function () { /* ANONYMOUS! */ return 'anon'; });
 	var anon2 = Object(function () { /* ANONYMOUS! */ return 'anon'; });
-	/* jscs: disable */
 	/* eslint-disable space-before-function-paren */
 	/* eslint-disable space-before-blocks */
 	var fnNoSpace = Object(function(){});
 	/* eslint-enable space-before-blocks */
 	/* eslint-enable space-before-function-paren */
-	/* jscs: enable */
 	var fnWithSpaceBeforeBody = Object(function () {});
 	var emptyFnWithName = Object(function a() {});
 	/* eslint-disable no-unused-vars */
@@ -564,7 +579,7 @@ test('functions', function (t) {
 			'functions with different names but same implementations are not equal'
 		);
 	}
-	t.equal('', isEqualWhy(f1, f2), 'functions with same names but same implementations are equal');
+	t.equal(isEqualWhy(f1, f2), '', 'functions with same names but same implementations are equal');
 	t.equal(
 		isEqualWhy(f1, f3),
 		'Function string representations differ',
@@ -725,6 +740,16 @@ test('functions', function (t) {
 		st.end();
 	});
 
+	/* eslint-disable no-unused-vars */
+	var fn = function f(x) { 'y'; };
+	var fnPlus = assign(function f(x) { 'y'; }, { a: 1 });
+	/* eslint-enable no-unused-vars */
+	t.equal(
+		isEqualWhy(fn, fnPlus),
+		'second argument has key "a"; first does not',
+		inspect(fn) + ' and ' + inspect(fnPlus) + ' are not equal'
+	);
+
 	t.end();
 });
 

why.js

@@ -98,8 +98,9 @@ module.exports = function whyNotEqual(value, other) {
 		if (!otherIsDate) { return 'first argument is Date, second is not'; }
 		var valTime = +value;
 		var otherTime = +other;
-		if (valTime === otherTime) { return ''; }
-		return 'Dates have different time values: ' + valTime + ' !== ' + otherTime;
+		if (valTime !== otherTime) {
+			return 'Dates have different time values: ' + valTime + ' !== ' + otherTime;
+		}
 	}
 
 	var valIsRegex = isRegex(value);
@@ -109,8 +110,9 @@ module.exports = function whyNotEqual(value, other) {
 		if (!otherIsRegex) { return 'first argument is RegExp, second is not'; }
 		var regexStringVal = String(value);
 		var regexStringOther = String(other);
-		if (regexStringVal === regexStringOther) { return ''; }
-		return 'regular expressions differ: ' + regexStringVal + ' !== ' + regexStringOther;
+		if (regexStringVal !== regexStringOther) {
+			return 'regular expressions differ: ' + regexStringVal + ' !== ' + regexStringOther;
+		}
 	}
 
 	var valIsArray = isArray(value);
@@ -170,7 +172,9 @@ module.exports = function whyNotEqual(value, other) {
 		return 'second argument is an arrow function; first is not';
 	}
 
-	if (isCallable(value) || isCallable(other)) {
+	var valueIsCallable = isCallable(value);
+	var otherIsCallable = isCallable(other);
+	if (valueIsCallable || otherIsCallable) {
 		if (functionsHaveNames && whyNotEqual(value.name, other.name) !== '') {
 			return 'Function names differ: "' + value.name + '" !== "' + other.name + '"';
 		}
@@ -181,20 +185,21 @@ module.exports = function whyNotEqual(value, other) {
 		var valueStr = normalizeFnWhitespace(String(value));
 		var otherStr = normalizeFnWhitespace(String(other));
 		if (
-			whyNotEqual(valueStr, otherStr) === ''
-			|| (
+			whyNotEqual(valueStr, otherStr) !== ''
+			&& !(
 				!valueIsGen
 				&& !valueIsArrow
 				&& whyNotEqual(valueStr.replace(/\)\s*\{/, '){'), otherStr.replace(/\)\s*\{/, '){')) === ''
 			)
 		) {
-			return '';
+			return 'Function string representations differ';
 		}
-
-		return 'Function string representations differ';
 	}
 
-	if (typeof value === 'object' || typeof other === 'object') {
+	var valueIsObj = valIsDate || valIsRegex || valIsArray || valueIsGen || valueIsArrow || valueIsCallable || Object(value) === value;
+	var otherIsObj = otherIsDate || otherIsRegex || otherIsArray || otherIsGen || otherIsArrow || otherIsCallable || Object(other) === other;
+
+	if (valueIsObj || otherIsObj) {
 		if (typeof value !== typeof other) { return 'arguments have a different typeof: ' + typeof value + ' !== ' + typeof other; }
 		if (isProto.call(value, other)) { return 'first argument is the [[Prototype]] of the second'; }
 		if (isProto.call(other, value)) { return 'second argument is the [[Prototype]] of the first'; }