fib_test.go

// Copyright © 2009-2011 Esko Luontola <www.orfjackal.net>
// This software is released under the Apache License 2.0.
// The license text is at http://www.apache.org/licenses/LICENSE-2.0

package examples

import (
	"github.com/orfjackal/gospec/src/gospec"
	. "github.com/orfjackal/gospec/src/gospec"
)

// The specs should read like a specification. The spec names in this example
// are straight from Wikipedia (http://en.wikipedia.org/wiki/Fibonacci_number)
// where the first paragraph defines the Fibonacci numbers as:
//
//     "By definition, the first two Fibonacci numbers are 0 and 1, and
//      each remaining number is the sum of the previous two."
//
// When the tests read like a specification, it is easier to find out what the
// system does by just reading the test names, and it is also easier to know
// whether the test is still needed when it fails.
//
// To learn more, see this article and tutorial:
// http://blog.orfjackal.net/2010/02/three-styles-of-naming-tests.html
// http://github.com/orfjackal/tdd-tetris-tutorial

func FibSpec(c gospec.Context) {
	fib := NewFib().Sequence(10)

	c.Specify("The first two Fibonacci numbers are 0 and 1", func() {
		c.Expect(fib[0], Equals, 0)
		c.Expect(fib[1], Equals, 1)
	})
	c.Specify("Each remaining number is the sum of the previous two", func() {
		for i := 2; i < len(fib); i++ {
			c.Expect(fib[i], Equals, fib[i-1]+fib[i-2])
		}
	})
}