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borachio/scaladoc

本家scaladocの翻訳

以下は2011/7/2時点のhttp://borachio.com/api/com/borachio/package.htmlの翻訳

Borachio: Native Scala mocking

ScalaTestでBorachioを使うには、suiteにMockFactoryトレイトをミックスする。 

class MyTest extends Suite with MockFactory

JUnit3にて使うには同じくMockFactoryをTestCaseにミックスする。 

class MyTest extends TestCase with MockFactory

Borachioは二つのモックスタイルをサポートする。ファンクショナルモッキングとプロキシモッキングである。

ファンクショナルモッキング

ファンクショナルモックはmockFunctionを使って生成される。例えば以下では一つのInt引数をとり、Stringを返すモック関数を作成する。 

val m = mockFunction[Int, String]

そしてこのモックファンクションにエクスペクテーションを設定する。 例えば以下では、このモックが一度だけ42という引数で呼び出され、"Forty two"を返すものとする。 

m expects (42) returning "Forty two" once

プロキシモッキング

mock（関数）によってプロキシモックを作成する。例えば以下は、Turtleトレイト（インターフェース）のすべてを実装するモックを作成する。 

val m = mock[Turtle]

そしてそれぞれのメソッドについてのエクスペクテーションをセットすることができる。例えば 

m expects 'setPosition withArgs (10.0, 10.0)
m expects 'forward withArgs (5.0)
m expects 'getPosition returning (15.0, 10.0)

エクスペクテーション

Expectations can be set on the arguments a function or method is called with and how many times it should be called. In addition, mocks can be instructed to return a particular value or throw an exception when that expectation is met. Arguments

To specify expected arguments for a functional mock, use expects. To specify expected arguments for a proxy mock, use withArgs or withArguments.

If no expected arguments are given, mocks accept any arguments.

To specify arguments that should simply be tested for equality, provide the expected arguments as a tuple:

m expects ("this", "that")

Borachio currently supports two types of generalized matching: wildcards and epsilon matching. Wildcards

Wildcard values are specified with an * (asterisk). For example:

m expects ("this", *)

will match any of the following:

m("this", 42) m("this", 1.0) m("this", null)

Epsilon matching

Epsilon matching is useful when dealing with floating point values. An epsilon match is specified with the ~ (tilde) operator:

m expects (~42.0)

will match:

m(42.0) m(42.0001) m(41.9999)

but will not match:

m(43.0) m(42.1)

Return value

Mocks can be instructed to return a specific value with returns or returning:

m1 returns 42 m2 expects ("this", "that") returning "the other"

If no return value is specified, functional mocks return null.asInstanceOf[R] where R is the return type (which equates to 0 for Int, 0.0 for Double etc.).

If no return value is specified, proxy mocks return null. This works correctly for most return types, but not for methods returning primitive types (Int, Double etc.), where returning null leads to a NullPointerException. So you will need to explicitly specify a return value for such methods. This restriction may be lifted in the future. Exceptions

Instead of a return value, a mock can be instructed to throw:

m expects ("this", "that") throws new RuntimeException("what's that?")

Call count

By default, mocks expect one or more calls (i.e. only fail if the function or method is never called). An exact number of calls or a range can be set with repeat:

m1 returns 42 repeat 3 to 7 m2 expects (3) repeat 10

There are various aliases for common expectations and styles:

m1 expects ("this", "that") once m2 returns "foo" noMoreThanTwice m3 expects (42) repeated 3 times

For a full list, see Expectation. Ordering

By default, expectations can be satisfied in any order. For example:

m expects (1) m expects (2) m(2) m(1)

A specific sequence can be enforced with inSequence:

inSequence {

  • m expects (1) m expects (2)

} m(2) // throws ExpectationException m(1)

Multiple sequences can be specified. As long as the calls within each sequence happen in the correct order, calls within different sequences can be interleaved. For example:

val m1 = mock[Turtle] val m2 = mock[Turtle]

inSequence {

  • m1 expects 'setPosition withArguments (0.0, 0.0) m1 expects 'penDown m1 expects 'forward withArguments (10.0) m1 expects 'penUp

} inSequence {

  • m2 expects 'setPosition withArguments(1.0, 1.0) m2 expects 'turn withArguments (90.0) m2 expects 'forward withArguments (1.0) m2 expects 'getPosition returning (2.0, 1.0)

}

m2.setPosition(1.0, 1.0) m1.setPosition(0.0, 0.0) m1.penDown m2.turn(90.0) m1.forward(10.0) m2.forward(1.0) m1.penUp expect((2.0, 1.0)) { m2.getPosition }

Debugging

If faced with a difficult to debug failing expectation, consider mixing one or both of the VerboseErrors or CallLogging traits into your test suite:

class MyTest extends Suite with MockFactory with VerboseErrors with CallLogging

Visibility

  • Public All

Type Members

Value Members