4.6 Writing Test Cases

Slate includes a port of Smalltalk's SUnit unit-testing framework (implemented in src/lib/test.slate), as well as a collection of unit tests (in tests/*.slate). Three namespaces are provided in which users may place their TestCases:

testing UnitTests

should contain unit-test cases;

testing RegressionTests

is for test cases covering bug fixes, for detecting regressions; and

testing BenchmarkTests

is to contain test cases for measuring the speed of the system.

There is a method testing runAllTests which runs all TestCases found in a recursive search of the UnitTests and RegressionsTests namespaces.

To write your own test cases, add a prototype derived from TestCase to the namespace you've chosen, within the appropriate container - either UnitTests or RegressionTests. For example, suppose you are writing test cases covering Ranges; you might write

UnitTests addPrototype: #Range derivedFrom: {TestCase}.

Once your prototype has been constructed, add tests to it. Test methods are unary methods with selectors beginning with test. For instance,

tc@(UnitTests Range traits) testInclusion1

"Verify that all elements of an Range are found in that Range."

[| range |

  range: (25 to: 50 by: 1).

  tc assert: (range allSatisfy: [| :item | range includes: item]).

].

The important assertion methods are

assert: Boolean

deny: Boolean

should: Method

should: Method raise: Condition

shouldnt: Method

shouldnt: Method raise: Condition

and variants with an additional description: String argument.

Once all your test methods are defined, a suite method should be defined that constructs a TestSuite for exercising the TestCase:

t@(UnitTests Range traits) suite

[t suiteForSelectors: {

  #testInclusion1.

  ``... etc. ...''

}].

See also the method TestCase suiteForSelectors:. The suite method is called by runSuite, which in turn is called by runAllTests.

At this point, invoking testing runAllTests will exercise your new code.