From 9f7a6ef06158b4753327e17fbde0cbe5841d2975 Mon Sep 17 00:00:00 2001
From: Steve Gravrock <sdg@panix.com>
Date: Sat, 28 Oct 2017 10:05:28 -0700
Subject: [PATCH] Check truthiness of toThrowError args, not arg count

This enables some useful simplifications at the cost of making it
impossible (for now) to expect a function to throw an error with a falsy
message.

[#20622765]
---
 lib/jasmine-core/jasmine.js       | 14 +++++++-------
 src/core/matchers/toThrowError.js | 14 +++++++-------
 2 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/lib/jasmine-core/jasmine.js b/lib/jasmine-core/jasmine.js
index cd744f21..1976a797 100644
--- a/lib/jasmine-core/jasmine.js
+++ b/lib/jasmine-core/jasmine.js
@@ -3755,18 +3755,18 @@ getJasmineRequireObj().toThrowError = function(j$) {
       var expected = null,
           errorType = null;
 
-      if (arguments.length == 2) {
-        expected = arguments[1];
-        if (isAnErrorType(expected)) {
-          errorType = expected;
-          expected = null;
-        }
-      } else if (arguments.length > 2) {
+      if (arguments[2]) {
         errorType = arguments[1];
         expected = arguments[2];
         if (!isAnErrorType(errorType)) {
           throw new Error(getErrorMsg('Expected error type is not an Error.'));
         }
+      } else if (arguments[1]) {
+        expected = arguments[1];
+        if (isAnErrorType(expected)) {
+          errorType = expected;
+          expected = null;
+        }
       }
 
       if (expected && !isStringOrRegExp(expected)) {
diff --git a/src/core/matchers/toThrowError.js b/src/core/matchers/toThrowError.js
index ef809e35..7cdc1d9f 100644
--- a/src/core/matchers/toThrowError.js
+++ b/src/core/matchers/toThrowError.js
@@ -71,18 +71,18 @@ getJasmineRequireObj().toThrowError = function(j$) {
       var expected = null,
           errorType = null;
 
-      if (arguments.length == 2) {
-        expected = arguments[1];
-        if (isAnErrorType(expected)) {
-          errorType = expected;
-          expected = null;
-        }
-      } else if (arguments.length > 2) {
+      if (arguments[2]) {
         errorType = arguments[1];
         expected = arguments[2];
         if (!isAnErrorType(errorType)) {
           throw new Error(getErrorMsg('Expected error type is not an Error.'));
         }
+      } else if (arguments[1]) {
+        expected = arguments[1];
+        if (isAnErrorType(expected)) {
+          errorType = expected;
+          expected = null;
+        }
       }
 
       if (expected && !isStringOrRegExp(expected)) {