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Camila Maia edited this page May 25, 2021 · 3 revisions

Tests are located in the tests folder. We only have unit tests in the project for now.

Unit Tests

Tools

For unit tests, we use pytest and pytest-it. If you are not familiar with these tools, please take a quick look at their official docs, it might help you:

Folder Structure

Unit tests are located in the tests/unit folder.

Test files should follow the same structure as the project itself and their names should start with test_. For example:

  • File: scanapi/evaluators/code_evaluator.py. Test File tests/unit/evaluators/test_code_evaluator.py
  • File: scanapi/scan.py. Test file: tests/unit/test_scan.py

If the test file gets too long, we create a folder and split the tests there. For example:

  • File: scanapi/tree/endpoint_node.py.
  • Test Files:
    • tests/unit/tree/endpoint_node/test_delay.py
    • tests/unit/tree/endpoint_node/test_get_requests.py
    • tests/unit/tree/endpoint_node/test_get_specs.py
    • ...

How to create a test

We create a separate class for each method we want to test. We add two describe decorators for this test class:

  • one for the class name that the method belongs to;
  • another for the method name itself.

We use context decorators to specify different scenarios. And, we use the it decorator for every test case, to describe what is the expected behavior.

Let's say we have the following file to be tested:

# my_file.py
class MyClassA:
    def method_1(self):
        pass
    
    def method_2(self):
        pass

class MyClassB:
    def method_3(self):
        pass

The test file test_my_file.py would look like something similar to this:

from pytest import mark


@mark.describe("my class a")
@mark.describe("method_1")
class TestMethod1:
    @mark.context("when scenario A happens")
    @mark.it("should do this")
    def test_should_do_this(self):
        # test here
        pass

    @mark.context("when scenario A happens")
    @mark.it("should not do that")
    def test_should_not_do_that(self):
        # test here
        pass

    @mark.context("when scenario B happens")
    @mark.it("should do another thing")
    def test_should_do_another_thing(self):
        # test here
        pass


@mark.describe("my class a")
@mark.describe("method_2")
class TestMethod2:
    @mark.context("when scenario C happens")
    @mark.it("should do something")
    def test_should_do_something(self):
        # test here
        pass

    @mark.context("when scenario D happens")
    @mark.it("should do another thing")
    def test_should_do_another_thing(self):
        # test here
        pass


@mark.describe("my class b")
@mark.describe("method_3")
class TestMethod3:
    @mark.context("when scenario E happens")
    @mark.it("should do something")
    def test_should_do_something(self):
        # test here
        pass

    @mark.context("when scenario F happens")
    @mark.it("should do another thing")
    def test_should_do_another_thing(self):
        # test here
        pass

The output for this would be like:

* tests/unit/test_my_file.py...
- Describe: My class a...

  - Describe: Method_1...

    - Context: When scenario a happens...
      - ✓ It: should do this
      - ✓ It: should not do that

    - Context: When scenario b happens...
      - ✓ It: should do another thing

  - Describe: Method_2...

    - Context: When scenario c happens...
      - ✓ It: should do something

    - Context: When scenario d happens...
      - ✓ It: should do another thing

- Describe: My class b...

  - Describe: Method_3...

    - Context: When scenario e happens...
      - ✓ It: should do something

    - Context: When scenario f happens...
      - ✓ It: should do another thing

Sometimes we have files without classes. It is not a problem, we can change the describe decorator to point out the file name

Let's say we have the following file to be tested:

# `my_file.py`
def method_1(self):
    pass


def method_2(self):
    pass

The test file test_my_file.py would look like something similar to this:

from pytest import mark


@mark.describe("my file")
@mark.describe("method_1")
class TestMethod1:
    @mark.context("when scenario A happens")
    @mark.it("should do this")
    def test_should_do_this(self):
        # test here
        pass

    @mark.context("when scenario A happens")
    @mark.it("should not do that")
    def test_should_not_do_that(self):
        # test here
        pass

    @mark.context("when scenario B happens")
    @mark.it("should do another thing")
    def test_should_do_another_thing(self):
        # test here
        pass

@mark.describe("my file")
@mark.describe("method_2")
class TestMethod2:
    @mark.context("when scenario C happens")
    @mark.it("should do something")
    def test_should_do_something(self):
        # test here
        pass

    @mark.context("when scenario D happens")
    @mark.it("should do another thing")
    def test_should_do_another_thing(self):
        # test here
        pass

The output for it would be like:

* tests/unit/test_my_file.py...
- Describe: My file...

  - Describe: Method_1...

    - Context: When scenario a happens...
      - ✓ It: should do this
      - ✓ It: should not do that

    - Context: When scenario b happens...
      - ✓ It: should do another thing

  - Describe: Method_2...

    - Context: When scenario c happens...
      - ✓ It: should do something

    - Context: When scenario d happens...
      - ✓ It: should do another thing

Examples

Do you wanna see real examples? Check the folder https://github.com/scanapi/scanapi/tree/master/tests/unit

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