Added approximately alias to close to

lib/chai/core/assertions.js

@@ -1445,27 +1445,31 @@ module.exports = function (chai, _) {
    *     expect(1.5).to.be.closeTo(1, 0.5);
    *
    * @name closeTo
+   * @alias approximately
    * @param {Number} expected
    * @param {Number} delta
    * @param {String} message _optional_
    * @api public
    */
 
-  Assertion.addMethod('closeTo', function (expected, delta, msg) {
+  function closeTo(expected, delta, msg) {
     if (msg) flag(this, 'message', msg);
     var obj = flag(this, 'object');
 
     new Assertion(obj, msg).is.a('number');
     if (_.type(expected) !== 'number' || _.type(delta) !== 'number') {
-      throw new Error('the arguments to closeTo must be numbers');
+      throw new Error('the arguments to closeTo or approximately must be numbers');
     }
 
     this.assert(
         Math.abs(obj - expected) <= delta
       , 'expected #{this} to be close to ' + expected + ' +/- ' + delta
       , 'expected #{this} not to be close to ' + expected + ' +/- ' + delta
     );
-  });
+  }
+
+  Assertion.addMethod('closeTo', closeTo);
+  Assertion.addMethod('approximately', closeTo);
 
   function isSubsetOf(subset, superset, cmp) {
     return subset.every(function(elem) {

lib/chai/interface/assert.js

@@ -1165,6 +1165,25 @@ module.exports = function (chai, util) {
   assert.closeTo = function (act, exp, delta, msg) {
     new Assertion(act, msg).to.be.closeTo(exp, delta);
   };
+
+  /**
+   * ### .approximately(actual, expected, delta, [message])
+   *
+   * Asserts that the target is equal `expected`, to within a +/- `delta` range.
+   *
+   *     assert.approximately(1.5, 1, 0.5, 'numbers are close');
+   *
+   * @name approximately
+   * @param {Number} actual
+   * @param {Number} expected
+   * @param {Number} delta
+   * @param {String} message
+   * @api public
+   */
+
+  assert.approximately = function (act, exp, delta, msg) {
+    new Assertion(act, msg).to.be.approximately(exp, delta);
+  };
 
   /**
    * ### .sameMembers(set1, set2, [message])

test/assert.js

@@ -707,11 +707,37 @@ describe('assert', function () {
 
     err(function() {
       assert.closeTo(1.5, "1.0", 0.5);
-    }, "the arguments to closeTo must be numbers");
+    }, "the arguments to closeTo or approximately must be numbers");
 
     err(function() {
       assert.closeTo(1.5, 1.0, true);
-    }, "the arguments to closeTo must be numbers");
+    }, "the arguments to closeTo or approximately must be numbers");
+  });
+
+  it('approximately', function(){
+    assert.approximately(1.5, 1.0, 0.5);
+    assert.approximately(10, 20, 20);
+    assert.approximately(-10, 20, 30);
+
+    err(function(){
+      assert.approximately(2, 1.0, 0.5);
+    }, "expected 2 to be close to 1 +/- 0.5");
+
+    err(function(){
+      assert.approximately(-10, 20, 29);
+    }, "expected -10 to be close to 20 +/- 29");
+
+    err(function() {
+      assert.approximately([1.5], 1.0, 0.5);
+    }, "expected [ 1.5 ] to be a number");
+
+    err(function() {
+      assert.approximately(1.5, "1.0", 0.5);
+    }, "the arguments to closeTo or approximately must be numbers");
+
+    err(function() {
+      assert.approximately(1.5, 1.0, true);
+    }, "the arguments to closeTo or approximately must be numbers");
   });
 
   it('members', function() {

test/expect.js

@@ -1046,11 +1046,37 @@ describe('expect', function () {
 
     err(function() {
       expect(1.5).to.be.closeTo("1.0", 0.5);
-    }, "the arguments to closeTo must be numbers");
+    }, "the arguments to closeTo or approximately must be numbers");
 
     err(function() {
       expect(1.5).to.be.closeTo(1.0, true);
-    }, "the arguments to closeTo must be numbers");
+    }, "the arguments to closeTo or approximately must be numbers");
+  });
+
+  it('approximately', function(){
+    expect(1.5).to.be.approximately(1.0, 0.5);
+    expect(10).to.be.approximately(20, 20);
+    expect(-10).to.be.approximately(20, 30);
+
+    err(function(){
+      expect(2).to.be.approximately(1.0, 0.5, 'blah');
+    }, "blah: expected 2 to be close to 1 +/- 0.5");
+
+    err(function(){
+      expect(-10).to.be.approximately(20, 29, 'blah');
+    }, "blah: expected -10 to be close to 20 +/- 29");
+
+    err(function() {
+      expect([1.5]).to.be.approximately(1.0, 0.5);
+    }, "expected [ 1.5 ] to be a number");
+
+    err(function() {
+      expect(1.5).to.be.approximately("1.0", 0.5);
+    }, "the arguments to closeTo or approximately must be numbers");
+
+    err(function() {
+      expect(1.5).to.be.approximately(1.0, true);
+    }, "the arguments to closeTo or approximately must be numbers");
   });
 
   it('include.members', function() {

test/should.js

@@ -875,11 +875,31 @@ describe('should', function() {
 
     err(function() {
       (1.5).should.be.closeTo("1.0", 0.5);
-    }, "the arguments to closeTo must be numbers");
+    }, "the arguments to closeTo or approximately must be numbers");
 
     err(function() {
       (1.5).should.be.closeTo(1.0, true);
-    }, "the arguments to closeTo must be numbers");
+    }, "the arguments to closeTo or approximately must be numbers");
+  });
+
+  it('approximately', function(){
+    (1.5).should.be.approximately(1.0, 0.5);
+
+    err(function(){
+      (2).should.be.approximately(1.0, 0.5, 'blah');
+    }, "blah: expected 2 to be close to 1 +/- 0.5");
+
+    err(function() {
+      [1.5].should.be.approximately(1.0, 0.5);
+    }, "expected [ 1.5 ] to be a number");
+
+    err(function() {
+      (1.5).should.be.approximately("1.0", 0.5);
+    }, "the arguments to closeTo or approximately must be numbers");
+
+    err(function() {
+      (1.5).should.be.approximately(1.0, true);
+    }, "the arguments to closeTo or approximately must be numbers");
   });
 
   it('include.members', function() {