Add delta message to closeTo() error

Author: eouw0o83hf

chai.js

@@ -3311,8 +3311,9 @@ module.exports = function (chai, _) {
     new Assertion(obj, flagMsg, ssfi, true).is.a('number');
     if (typeof expected !== 'number' || typeof delta !== 'number') {
       flagMsg = flagMsg ? flagMsg + ': ' : '';
+      var deltaMessage = delta === undefined ? ", and a delta is required" : "";
       throw new AssertionError(
-          flagMsg + 'the arguments to closeTo or approximately must be numbers',
+          flagMsg + 'the arguments to closeTo or approximately must be numbers' + deltaMessage,
           undefined,
           ssfi
       );

lib/chai/core/assertions.js

@@ -2950,8 +2950,9 @@ module.exports = function (chai, _) {
     new Assertion(obj, flagMsg, ssfi, true).is.a('number');
     if (typeof expected !== 'number' || typeof delta !== 'number') {
       flagMsg = flagMsg ? flagMsg + ': ' : '';
+      var deltaMessage = delta === undefined ? ", and a delta is required" : "";
       throw new AssertionError(
-          flagMsg + 'the arguments to closeTo or approximately must be numbers',
+          flagMsg + 'the arguments to closeTo or approximately must be numbers' + deltaMessage,
           undefined,
           ssfi
       );

test/assert.js

@@ -1848,6 +1848,10 @@ describe('assert', function () {
     err(function() {
       assert.closeTo(1.5, 1.0, true, 'blah');
     }, "blah: the arguments to closeTo or approximately must be numbers");
+
+    err(function() {
+      assert.closeTo(1.5, 1.0, undefined, 'blah');
+    }, "blah: the arguments to closeTo or approximately must be numbers, and a delta is required");
   });
 
   it('approximately', function(){
@@ -1874,6 +1878,10 @@ describe('assert', function () {
     err(function() {
       assert.approximately(1.5, 1.0, true, 'blah');
     }, "blah: the arguments to closeTo or approximately must be numbers");
+
+    err(function() {
+      assert.approximately(1.5, 1.0, undefined, 'blah');
+    }, "blah: the arguments to closeTo or approximately must be numbers, and a delta is required");
   });
 
   it('sameMembers', function() {