jasmine/suites-and-specs.html.md

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---
layout: default
title: Suites & Specs
---
## Specs
Each spec is, naturally, a JavaScript function. You tell Jasmine about a spec with a call to `it()` with a description string and the function. The string is a description of a behavior that you want your production code to exhibit; it should be meaningful to you when reading a report.
it('should increment a variable', function () {
var foo = 0;
foo++;
});
## Expectations
Within your spec you will express expectations about the behavior of your application code. This is done using the `expect()` function and any of various expectation matchers, like this:
it('should increment a variable', function () {
var foo = 0; // set up the world
foo++; // call your application code
expect(foo).toEqual(1); // passes because foo == 1
});
Results of the expectations will be reported to you when the spec is run.
### Suites
Specs are grouped in Suites. Suites are defined using the global `describe()` function:
describe('Calculator', function () {
it('can add a number', function () {
...
});
it('has multiply some numbers', function () {
...
});
});
The Suite name is typically the name of a class or other applicaton component, and will be reported with results when your specs are run.
Suites are executed in the order in which `describe()` calls are made, usually in the order in which their script files are included. Additionally, specs within a suite share a functional scope. So you may declare variables inside a describe block and they are accessible from within your specs. For example:
describe('Calculator', function () {
var counter = 0
it('can add a number', function () {
counter = counter + 2; // counter was 0 before
expect(bar).toEqual(2);
});
it('can multiply a number', function () {
counter = counter * 5; // counter was 2 before
expect(bar).toEqual(10);
});
});
Be aware that code directly inside the `describe()` function is only executed once, which is why `counter` in the above example is not reset to `0` for the second spec. If you want to initialize variables before each spec, use a `beforeEach()` function.
### Nested Describes
Jasmine supports nested describes. An example:
describe('some suite', function () {
var suiteWideFoo;
beforeEach(function () {
suiteWideFoo = 0;
});
describe('some nested suite', function() {
var nestedSuiteBar;
beforeEach(function() {
nestedSuiteBar=1;
});
it('nested expectation', function () {
expect(suiteWideFoo).toEqual(0);
expect(nestedSuiteBar).toEqual(1);
});
});
it('top-level describe', function () {
expect(suiteWideFoo).toEqual(0);
expect(nestedSuiteBar).toEqual(undefined);
});
});
### Disabling Tests & Suites
Specs may be disabled by calling `xit()` instead of `it()`. Suites may be disabled by calling `xdescribe()` instead of `describe()`.