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Update docs about Matchers to use addMatcher().

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Christian Williams 2010-02-20 14:44:58 -05:00
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@ -98,36 +98,33 @@ Results of the expectations are logged for later for reporting.
Jasmine has several built-in matchers. Here are a few:
`toEqual()` compares objects or primitives and returns true if they are equal
`toNotEqual()` compares objects or primitives and returns true if they are not equal
`toMatch()` takes a regex or a string and returns true if it matches
`toNotMatch()` takes a regex or a string and returns true if it does not match
`toBeDefined()` returns true if the object or primitive is not `undefined`
`toBeNull()` returns true if the object or primitive is not `null`
`toBeTruthy()` returns true if the object or primitive evaluates to true
`toBeFalsy()` returns true if the object or primitive evaluates to false
`toContain()` returns true if an array or string contains the passed variable.
`toNotContain()` returns true if an array or string does not contain the passed variable.
>`expect(x).toEqual(y);` compares objects or primitives `x` and `y` and passes if they are equivalent
>`expect(x).toMatch(pattern);` compares `x` to string or regular expression `pattern` and passes if they match
>`expect(x).toBeDefined();` passes if `x` is not `undefined`
>`expect(x).toBeNull();` passes if `x` is not `null`
>`expect(x).toBeTruthy();` passes if `x` evaluates to true
>`expect(x).toBeFalsy();` passes if `x` evaluates to false
>`expect(x).toContain(y);` passes if array or string `x` contains `y`
#### Writing New Matchers
A Matcher has a method name, takes an expected value as it's only parameter, has access to the actual value in this, and then makes a call to this.report with true/false with a failure message. Here's the definition of `toEqual()`:
We've provided a small set of matchers that cover many common situations. However, we recommend that you write custom matchers when you want to assert a more specific sort of expectation. Custom matchers help to document the intent of your specs, and can help to remove code duplication in your specs.
jasmine.Matchers.prototype.toEqual = function (expected) {
return this.report((this.actual === expected),
'Expected ' + expected + ' but got ' + this.actual + '.');
It's extremely easy to create new matchers for your app. A matcher function receives the actual value as `this.actual`, and zero or more arguments may be passed in the function call. The function should return `true` if the actual value passes the matcher's requirements, and `false` if it does not.
Here's the definition of `toBeLessThan()`:
toBeLessThan: function(expected) {
return this.actual < expected;
};
Feel free to define your own matcher as needed in your code. If you'd like to add Matchers to Jasmine, please write tests.
To add the matcher to your suite, call `this.addMatchers()` from within a `before` or `it` block. Call it with an object mapping matcher name to function:
beforeEach(function() {
this.addMatchers({
toBeVisible: function() { return this.actual.isVisible(); }
});
});
### Asynchronous Specs