[Fix] improve error message when callability is mismatched

inspect-js · Oct 5, 2023 · dc0f577 · dc0f577
1 parent fa8d0ae
commit dc0f577
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diff --git a/test/why.js b/test/why.js
@@ -412,6 +412,16 @@ test('arrays', function (t) {
 });
 
 test('objects', function (t) {
+	t.test('fake toStringTag', { skip: !symbolToStringTag }, function (st) {
+		var fake = function () {};
+		fake[symbolToStringTag] = 'Object';
+
+		st.equal(isEqualWhy({}, fake), 'second argument is callable; first is not');
+		st.equal(isEqualWhy(fake, {}), 'first argument is callable; second is not');
+
+		st.end();
+	});
+
 	t.test('prototypes', function (st) {
 		var F = function F() {
 			this.foo = 42;

diff --git a/why.js b/why.js
@@ -202,6 +202,9 @@ module.exports = function whyNotEqual(value, other) {
 	var valueIsCallable = isCallable(value);
 	var otherIsCallable = isCallable(other);
 	if (valueIsCallable || otherIsCallable) {
+		if (valueIsCallable !== otherIsCallable) {
+			return valueIsCallable ? 'first argument is callable; second is not' : 'second argument is callable; first is not';
+		}
 		if (functionsHaveNames && whyNotEqual(value.name, other.name) !== '') {
 			return 'Function names differ: "' + value.name + '" !== "' + other.name + '"';
 		}