1 # Test unit generation and execution for Nit.
3 In Nit, unit testing can be achieved in two ways:
5 * using `DocUnits` in code comments
6 * using `TestSuites` with test unit files
8 DocUnits are executable pieces of code found in the documentation of modules,
9 classes and properties.
10 They are used for documentation purpose, they should be kept simple and illustrative.
11 More advanced unit testing can be done using TestSuites.
13 TestSuites are test files coupled to a tested module.
14 They contain a list of test methods called TestCase.
16 ## Working with `DocUnits`
18 With DocUnits, executable code can be placed in comments of modules, classes and properties.
19 The execution can be verified using `assert`
26 # assert foo.bar == 10
31 Everything used in the test must be declared.
32 To test a method you have to instanciate its class:
37 # assert foo.bar == 10
40 # assert foo.baz(1, 2) == 3
41 fun baz(a, b: Int) do return a + b
44 `nitunit` is used to test Nit files:
48 ## Working with `TestSuites`
50 TestSuites are Nit files that define a set of TestCase for a particular module.
52 The test suite module must be declared using the `test` annotation.
53 The structure of a test suite is the following:
55 # test suite for module `foo`
56 module test_foo is test
58 import foo # can be intrude to test private things
63 # test case for `foo::Foo::baz`
66 assert subject.baz(1, 2) == 3
70 Test suite can be executed using the same `nitunit` command:
74 To be started automatically with nitunit, the module must be called `test_`
75 followed by the name of the module to test.
76 So for the module `foo.nit` the test suite will be called `test_foo.nit`.
77 Otherwise, you can use the `-t` option to specify the test suite module name:
79 $ nitunit foo.nit -t my_test_suite.nit
81 `nitunit` will execute a test for each method annotated with `test` in a class also annotated with `test`
82 so multiple tests can be executed for a single method:
89 assert subject.baz(1, 2) == 3
94 assert subject.baz(1, -2) == -1
98 `TestSuites` also provide methods to configure the test run:
100 `before` and `after` annotations can be added to methods that must be called before/after each test case.
101 They can be used to factorize repetitive tasks:
106 var subject: Foo is noinit
108 # Method executed before each test
109 redef fun set_up is before do
114 assert subject.baz(1, 2) == 3
118 assert subject.baz(1, -2) == -1
122 When using custom test attributes, a empty init must be declared to allow automatic test running.
124 `before_all` and `after_all` annotations can be set on methods that must be called before/after each test suite.
125 They have to be declared at top level:
127 module test_bdd_connector
131 # Testing the bdd_connector
134 # test cases using a server
137 # Method executed before testing the module
138 fun before_module is before_all do
139 # start server before all test cases
142 # Method executed after testing the module
143 fun after_module is after_all do
144 # stop server after all test cases
147 ## Generating test suites
149 Write test suites for big modules can be a pepetitive and boring task...
150 To make it easier, `nitunit` can generate test skeletons for Nit modules:
152 $ nitunit --gen-suite foo.nit
154 This will generate the test suite `test_foo` containing test case stubs for all public
155 methods found in `foo.nit`.
157 Useful options with `--gen-suite`:
159 * `--private`: also generate tests for protected and private methods
160 * `--force`: force generation of the skeleton (existing test suite will be overwritten)