feat(matchers): Allow for objects in oneOf

lib/chai/core/assertions.js

@@ -1534,10 +1534,17 @@ module.exports = function (chai, _) {
   /**
    * ### .oneOf(list)
    *
-   * Assert that a non-array, non-object value appears somewhere in the flat array `list`.
+   * Assert that a value appears somewhere in the top level of array `list`.
    *
    *     expect('a').to.be.oneOf(['a', 'b', 'c']);
    *     expect(9).to.not.be.oneOf(['z']);
+   *     expect([3]).to.not.be.oneOf([1, 2, [3]]);
+   *
+   *     var three = [3];
+   *     // for object-types, contents are not compared
+   *     expect(three).to.not.be.oneOf([1, 2, [3]]);
+   *     // comparing references works
+   *     expect(three).to.be.oneOf([1, 2, three]);
    *
    * @name oneOf
    * @param {Array<*>} list
@@ -1549,13 +1556,11 @@ module.exports = function (chai, _) {
     if (msg) flag(this, 'message', msg);
     var expected = flag(this, 'object');
     new Assertion(list).to.be.an('array');
-    new Assertion(expected).to.not.be.an('array');
-    new Assertion(expected).to.not.be.an('object');
 
     this.assert(
         list.indexOf(expected) > -1
-      , 'expected #{this} to be in #{exp}'
-      , 'expected #{this} to not be in #{exp}'
+      , 'expected #{this} to be one of #{exp}'
+      , 'expected #{this} to not be one of #{exp}'
       , list
       , expected
     );

test/assert.js

@@ -771,25 +771,31 @@ describe('assert', function () {
   it('oneOf', function() {
     assert.oneOf(1, [1, 2, 3]);
 
-    err(function() {
-      assert.oneOf([1], []);
-    }, 'expected [ 1 ] not to be an array');
+    var three = [3];
+    assert.oneOf(three, [1, 2, three]);
 
-    err(function() {
-      assert.oneOf({a: 1}, []);
-    }, 'expected { a: 1 } not to be an object');
+    var four = { four: 4 };
+    assert.oneOf(four, [1, 2, four]);
 
     err(function() {
       assert.oneOf(1, 1);
     }, 'expected 1 to be an array');
 
     err(function() {
-      assert.oneOf(1, {a: 1});
+      assert.oneOf(1, { a: 1 });
     }, 'expected { a: 1 } to be an array');
 
     err(function() {
       assert.oneOf(9, [1, 2, 3], 'Message');
-    }, 'Message: expected 9 to be in [ 1, 2, 3 ]');
+    }, 'Message: expected 9 to be one of [ 1, 2, 3 ]');
+
+    err(function() {
+      assert.oneOf([3], [1, 2, [3]]);
+    }, 'expected [ 3 ] to be one of [ 1, 2, [ 3 ] ]');
+
+    err(function() {
+      assert.oneOf({ four: 4 }, [1, 2, { four: 4 }]);
+    }, 'expected { four: 4 } to be one of [ 1, 2, { four: 4 } ]');
 
   });
 

test/expect.js

@@ -1082,6 +1082,9 @@ describe('expect', function () {
   it('oneOf', function() {
     expect(1).to.be.oneOf([1, 2, 3]);
     expect('1').to.not.be.oneOf([1, 2, 3]);
+    expect([3, [4]]).to.not.be.oneOf([1, 2, [3, 4]]);
+    var threeFour = [3, [4]];
+    expect(threeFour).to.be.oneOf([1, 2, threeFour]);
   });
 
   it('include.members', function() {