Additional assertions for referee.

At the moment, only matchers for arrays and array-like objects are provided.

Similar to assert.contains, the following assertions are provided:

• assert.containsOnce(array, element) passes if array contains element exactly once.

• assert.containsInOrder(array, a, b, c, ...) passes if array contains all passed-in values in that order.

The following assertions check for matching elements. See the documentation of assert.match to understand how referee matches.

• assert.containsMatch(array, matcher) passes if any element in array matches matcher.

• assert.containsMatchOnce(array, matcher) passes if exactly one element in array matches matcher.

• assert.containsMatchesInOrder(array, matcherA, matcherB, ...) passes if elements matching the passed-in matchers are contained in the given order.

These assertions check sequence elements by equality. Read the documentation of assert.equals to understand how referee checks for equality.

• assert.containsEqual(array, value) passes if any element in array equals value.

• assert.containsEqualOnce(array, value) passes if exactly one element in array equals value.

• assert.containsEqualsInOrder(array, valueA, valueB, ...) passes if elements equaling the passed-in values are contained in the given order.

This assertion checks whether a string (or string representation of an object) contains a substring.

Contributions welcome! Please make sure that your assertion functions are properly tested. Don’t test assert.myAssert(), but only the assertion function.