Beginnings of an introduction to test-first javascript development inspired by Jim Weirich's Ruby Koans.

string js koans

// Written by Rachel Myers as a introduction to test-first javascript development.
// Inspired by and very nearly lifted from Jim Weirich's Ruby Koans, which are awesome.

describe("Strings", function() {
	
	describe("Creating Strings", function() {
		var double_quote_string;
		var single_quote_string;
		var talking_string;
		var apostrophe_string;
		
		it("should create a new string with double quotes", function(){
			expect(double_quote_string).toEqual("We have acrobats!");
		});

		it("should create a string with single quotes", function(){
			expect(single_quote_string).toEqual('We have clowns!');
		});

		it("should use single quotes to contain double quotes", function(){
			expect(talking_string).toEqual('I said, "We have clowns!"');
		});

		it("should use double quotes to contain single quotes", function(){
			expect(apostrophe_string).toEqual("It's a limited engagement.");
		});
	});

	describe("Character and Substring Access", function() {
		var character;
		var no_such_character;
		var index;
		var no_such_index;
		var none_such_index;
		
		beforeEach(function() {
			double_quote_string = "We have acrobats!"; // Unnecessary if previous tests passed.
		});

		it("should use charAt to access a character from a string", function(){
			expect(character).toEqual("a");
			// looking for: double_quote_string.charAt(4)
		});

		it("returns empty string if index is larger than string", function(){
			expect(no_such_character).toEqual("");
			// looking for something like: double_quote_string.charAt(17)
		});

		it("should use indexOf to find index of 'bats' substring", function(){
			expect(index).toEqual(12);
			// looking for: double_quote_string.indexOf("bats")
		});

		it ("should return -1 if there's substring doesn't exist", function(){
			expect(no_such_index).toEqual(-1);
			//looking for something like: double_quote_string.indexOf(birds)
		});

		it ("show indexOf is will not find 'Bats", function(){
			expect(none_such_index).toEqual(-1);
			//looking for: double_quote_string.indexOf(Bats)
		});
	});
	
	describe("Concatenation and Splitting", function() {
		var question = "And do you know what else?";
		var answer = "We also have lots of clowns.";
		var elaboration = "How do they all fit in that car?";
		
		var concatenation;
		var long_concatenation;
		var split_answer;
		var no_such_split;
		var strangely_split_answer;
		
		it ("should concatenate two strings", function(){
			expect(concatenation).toEqual("And do you know what else?  We also have lots of clowns.");
			//looking for: concat(question, answer)
		});

		it ("should concatenate many strings", function(){
			expect(long_concatenation).toEqual("And do you know what else?  We also have lots of clowns.  How do they all fit in that car?");
			//looking for: concat(question, answer, elaboration)
		});
		
		it ("should split strings", function(){
			expect(split_answer).toEqual(["We", "also", "have", "lots", "of", "clowns."]);
			//looking for: answer.split()
		});
		
		it ("should split an empty string into an array containing an empty string", function(){
			expect(no_such_split).toEqual([""]);
			//looking for: "".split()
		});
		
		it ("should split strings by any character we want", function(){
			expect(answer_split_by_o).toEqual(["We als", "have l", "ts", "fcl", "wns."]);
			//looking for: answer.split(["o"])
		});
	});

	describe("Formating Strings", function() {
		var statement = "  I love the circus!  ";
		
		var screaming;
		var whispering;
		var trimmed;
		
		it ("should make a statement uppercase", function(){
			expect(screaming).toEqual("  I LOVE THE CIRCUS!  ");
			//looking for: sentence.toUpperCase()
		});
		
		it ("should make a statement lowercase", function(){
			expect(whispering).toEqual("  i love the circus!  ");
			//looking for: sentence.toLowerCase()
		});

		it ("should remove white space", function(){
			expect(trimmed).toEqual("I love the circus!");
			//looking for: sentence.trim()
		});
	});
});