fix: cause last element index check

Author: dmuharemagic

index.js

@@ -23,7 +23,7 @@ function createError (code, message, statusCode = 500, Base = Error) {
     this.statusCode = statusCode
 
     const lastElement = args.length - 1
-    if (lastElement !== 1 && args[lastElement] && typeof args[lastElement] === 'object' && 'cause' in args[lastElement]) {
+    if (lastElement !== -1 && args[lastElement] && typeof args[lastElement] === 'object' && 'cause' in args[lastElement]) {
       this.cause = args.pop().cause
     }
 

test/index.test.js

@@ -163,6 +163,16 @@ test('Create an error with cause', t => {
   t.equal(err.cause, cause)
 })
 
+test('Create an error with cause and message', t => {
+  t.plan(2)
+  const cause = new Error('HEY')
+  const NewError = createError('CODE', 'Not available: %s')
+  const err = NewError('foo', { cause })
+
+  t.ok(err instanceof Error)
+  t.equal(err.cause, cause)
+})
+
 test('Create an error with last argument null', t => {
   t.plan(2)
   const cause = new Error('HEY')