From fa68b7f42edca8eeab19e1850a3ae768edab3d34 Mon Sep 17 00:00:00 2001
From: Tom Jenkinson <tom@tjenkinson.me>
Date: Thu, 29 Oct 2020 09:20:06 +0000
Subject: [PATCH] fix matching exact args

---
 src/when.js      | 2 +-
 src/when.test.js | 5 ++---
 2 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/src/when.js b/src/when.js
index bf69246..8df777a 100644
--- a/src/when.js
+++ b/src/when.js
@@ -68,7 +68,7 @@ class WhenMock {
           if (once && called) continue
 
           const isMatch =
-            args.length <= matchers.length &&
+            args.length === matchers.length &&
             matchers.reduce(checkArgumentMatchers(expectCall, args), true)
 
           if (isMatch) {
diff --git a/src/when.test.js b/src/when.test.js
index d3ae397..3e6124d 100644
--- a/src/when.test.js
+++ b/src/when.test.js
@@ -160,7 +160,7 @@ describe('When', () => {
       const anyString = expect.any(String)
 
       when(fn)
-        .calledWith(1, 'foo', true, anyString, undefined)
+        .calledWith(1, 'foo', true, anyString)
         .mockReturnValue('x')
 
       expect(fn(1, 'foo', true, 'whatever')).toEqual('x')
@@ -168,7 +168,6 @@ describe('When', () => {
       expect(spyEquals).toBeCalledWith('foo', 'foo')
       expect(spyEquals).toBeCalledWith(true, true)
       expect(spyEquals).toBeCalledWith('whatever', anyString)
-      expect(spyEquals).toBeCalledWith(undefined, undefined)
     })
 
     it('only matches exact sets of args, too little or too many args do not trigger mock return', () => {
@@ -178,7 +177,7 @@ describe('When', () => {
         .calledWith(1, 'foo', true, expect.any(String), undefined)
         .mockReturnValue('x')
 
-      expect(fn(1, 'foo', true)).toEqual(undefined)
+      expect(fn(1, 'foo', true, 'whatever')).toEqual(undefined)
       expect(fn(1, 'foo', true, 'whatever', undefined, 'oops')).toEqual(undefined)
     })