`unittest`: Unit testing framework

This module contains a simple unit testing framework that can be used for implementing automated unit tests for Alore programs.

Introduction

A test case tests a single feature of a program. A suite is a collection of related test cases. Typically test cases are implemented as methods of a test suite class. A test suite class must be a subclass of Suite.

The class below is a simple test suite that tests functions in the mymodule module, which we assume to define the function Add and Multiply:

import unittest
import mymodule

class MySuite is Suite
  def testAdd()
    AssertEqual(Add(1, 1), 2)
  end
  
  def testMultiply()
    AssertEqual(Multiply(2, 3), 6)
  end
end

Only methods whose names start with "test" become test cases of a suite. The AssertEqual function can be used to verify that two values are equal.

The RunTest function is used to execute a test suite:

RunTest(MySuite())

The above program executes the two test cases testAdd and testMultiply. Any test cases that raise an uncaught exception due to an assertion failure or any other reason are reported to the programmer.

If we save the program above as test.alo, we can run the test cases like this:

$ alore test.alo
2 test cases run, all passed.
*** OK ***
$

The Suite class

class Suite(): Construct a Suite object. All members defined in subclasses that start with test are assumed to represent test cases or child suites. Members that are instances of Suite represent child suites and other members are assumed to represent test cases.

Suite methods

addTest(testcase): Add a test case to the suite. This method can be used to add manually constructed instances of the TestCase class or its subclass as members of a suite.
setUp(): This method is called before executing each test case in the suite. The default implementation does nothing. Override this to setup member variables, files and other common state needed by test cases.
tearDown(): This method is usually called after executing each test case in the suite, even if the test case failed. The default implementation does nothing. Override this to clean up the results of the setUp method or test cases.
skip(): Skip the current test case. The number of skipped test cases is reported by RunTest, and if the "-v" flag is present, they are also marked in the list of executed test cases as skipped.

The TestCase class

class TestCase(name[, suite[, function]]): Construct a test case object. The optional suite argument defines the test suite that contains this test case. The optional function argument, a callable object that accepts no arguments, will be called when the case is run.

TestCase methods

setUp(): If suite is defined, calls the setUp method of the suite. setUp is called before running the test case.
tearDown(): If suite is defined, calls the tearDown method of the suite. tearDown is called after running the test case even if the test case failed.
run(): Run the test case. By default, calls the function given to the constructor or does nothing if the function was not provided. This method should raise an exception on test case failure.

Functions

RunTest(test[, args])

Run a test case or a test suite. The optional args parameter may be a sequence of strings that represent the command line arguments to the tester. Status information is displayed on the StdOut stream.

The args array optionally starts with a "-v" flag. If present, it causes the function to display the names of all test cases as they are being run. Finally, the args array may contain a test case filter pattern. The pattern may contain asterisks (*) as wild card characters. It is used to specify the names of test cases to run.

Member test... of a test suite is named test.., unless the test suite is a child suite, in which case the name is prefixed with the name of the parent test suite and a dot (.).

For example, if args is ["testChild.*"], only the test cases in the testChild child suite are run.

Fail()

Fail a test case by raising AssertionFailure.

Assert(bool[, message])

Raise AssertionFailure if bool is not True. If the message is provided, it is associated with the exception.

AssertEqual(a, b)

Raise AssertionFailure if a != b.

AssertNotEqual(a, b)

Raise AssertionFailure if a == b.

AssertRaises(exception[, message], function, arguments = [])

Call the function with the given arguments. Raise AssertionFailure if the function does not raise an exception of the type specified by exception. Additionally, if the message argument is given, verify that the message member of the exception is equal to the message argument. Example:

AssertRaises(TypeError, Ord, [5]) -- Verify that Ord does not accept
                                  -- an integer argument.

AssertType(type, x)

Raise AssertionFailure if x is not an instance of the specified type.

Note: Instances of subclasses of the type are not accepted.

Exceptions

class AssertionFailure([message]): This exception is raised when an assertion is failed in a test case. This class is derived from std::Exception.

unittest: Unit testing framework