shouldjs · wmzy · Sep 30, 2019
diff --git a/lib/ext/_assert.js b/lib/ext/_assert.js
@@ -206,7 +206,7 @@ function expectedException(actual, expected) {

  if (Object.prototype.toString.call(expected) == "[object RegExp]") {
    return expected.test(actual);
-  } else if (actual instanceof expected) {
+  } else if (expected.prototype && actual instanceof expected) {
    return true;
  } else if (expected.call({}, actual) === true) {
    return true;

diff --git a/test/ext/assert.test.js b/test/ext/assert.test.js
@@ -251,6 +251,9 @@ describe("assert", function() {
    );
    threw = false;

+    // if passing a arrow function, catch all
+    assert.throws(makeBlock(thrower, TypeError), () => true);
+
    // doesNotThrow should pass through all errors
    try {
      assert.doesNotThrow(makeBlock(thrower, TypeError), assert.AssertionError);