Flask Testing 中文文檔 · Flask 擴展文檔匯總

# Flask-Testing **Flask-Testing** 擴展為 Flask 提供了單元測試的工具。 ## 安裝 Flask-Testing 使用 **pip** 或者 **easy_install** 安裝: ``` pip install Flask-Testing ``` 或者從版本控制系統(github)中下載最新的版本: ``` git clone https://github.com/jarus/flask-testing.git cd flask-testing python setup.py develop ``` 如果你正在使用 **virtualenv**，假設你會安裝 **Flask-Testing** 在運行你的 Flask 應用程序的同一個 virtualenv 上。 ## 編寫測試用例簡單地繼承 `TestCase` 的 MyTest: ``` from flask.ext.testing import TestCase class MyTest(TestCase): pass ``` 你必須定義 `create_app` 方法，該方法返回一個 Flask 實例: ``` from flask import Flask from flask.ext.testing import TestCase class MyTest(TestCase): def create_app(self): app = Flask(__name__) app.config['TESTING'] = True return app ``` 如果不定義 `create_app`，`NotImplementedError` 異常將會拋出。 ### 使用 LiveServer 測試如果你想要你的測試通過 Selenium 或者無頭瀏覽器(無頭瀏覽器的意思就是無外設的意思，可以在命令行下運行的瀏覽器)運行，你可以使用 LiveServerTestCase: ``` import urllib2 from flask import Flask from flask.ext.testing import LiveServerTestCase class MyTest(LiveServerTestCase): def create_app(self): app = Flask(__name__) app.config['TESTING'] = True # Default port is 5000 app.config['LIVESERVER_PORT'] = 8943 return app def test_server_is_up_and_running(self): response = urllib2.urlopen(self.get_server_url()) self.assertEqual(response.code, 200) ``` 在這個例子中 `get_server_url` 方法將會返回 [http://localhost:8943](http://localhost:8943)。 ### 測試 JSON 響應如果你正在測試一個返回 JSON 的視圖函數的話，你可以使用 `Response` 對象的特殊的屬性 `json` 來測試輸出: ``` @app.route("/ajax/") def some_json(): return jsonify(success=True) class TestViews(TestCase): def test_some_json(self): response = self.client.get("/ajax/") self.assertEquals(response.json, dict(success=True)) ``` ### 選擇不渲染模板當測試需要處理模板渲染的時候可能是一個大問題。如果在測試中你不想要渲染模板的話可以設置 `render_templates` 屬性: ``` class TestNotRenderTemplates(TestCase): render_templates = False def test_assert_not_process_the_template(self): response = self.client.get("/template/") assert "" == response.data ``` 盡管可以設置不想渲染模板，但是渲染模板的信號在任何時候都會發送，你也可以使用 `assert_template_used` 方法來檢查模板是否被渲染: ``` class TestNotRenderTemplates(TestCase): render_templates = False def test_assert_mytemplate_used(self): response = self.client.get("/template/") self.assert_template_used('mytemplate.html') ``` 當渲染模板被關閉的時候，測試執行起來會更加的快速并且視圖函數的邏輯將會孤立地被測試。 ### 使用 Twill [Twill](http://twill.idyll.org/) 是一個用來通過使用命令行界面瀏覽網頁的簡單的語言。 Note 請注意 Twill 只支持 Python 2.x，不能在 Python 3 或者以上版本上使用。 `Flask-Testing` 擁有一個輔助類用來創建使用 Twill 的功能測試用例: ``` def test_something_with_twill(self): with Twill(self.app, port=3000) as t: t.browser.go(t.url("/")) ``` 舊的 `TwillTestCase` 類已經被棄用。 ### 測試 SQLAlchemy 這部分將會涉及使用 **Flask-Testing** 測試 [SQLAlchemy](http://sqlalchemy.org) 的一部分內容。這里假設你使用的是 [Flask-SQLAlchemy](http://packages.python.org/Flask-SQLAlchemy/) 擴展，并且這里的例子也不是太難，可以適用于用戶自己的配置。首先，先確保數據庫的 URI 是設置成開發環境而不是生產環境！其次，一個好的測試習慣就是在每一次測試執行的時候先創建表，在結束的時候刪除表，這樣保證干凈的測試環境: ``` from flask.ext.testing import TestCase from myapp import create_app, db class MyTest(TestCase): SQLALCHEMY_DATABASE_URI = "sqlite://" TESTING = True def create_app(self): # pass in test configuration return create_app(self) def setUp(self): db.create_all() def tearDown(self): db.session.remove() db.drop_all() ``` 同樣需要注意地是每一個新的 SQLAlchemy 會話在測試用例運行的時候就被創建， `db.session.remove()` 在每一個測試用例的結尾被調用(這是為了確保 SQLAlchemy 會話及時被刪除) - 這是一種常見的 “陷阱”。另外一個 “陷阱” 就是 Flask-SQLAlchemy 會在每一個請求結束的時候刪除 SQLAlchemy 會話(session)。因此每次調用 `client.get()` 或者其它客戶端方法的后，SQLAlchemy 會話(session)連同添加到它的任何對象都會被刪除。例如: ``` class SomeTest(MyTest): def test_something(self): user = User() db.session.add(user) db.session.commit() # this works assert user in db.session response = self.client.get("/") # this raises an AssertionError assert user in db.session ``` 你現在必須重新添加 “user” 實例回 SQLAlchemy 會話(session)使用 `db.session.add(user)`，如果你想要在數據庫上做進一步的操作。同樣需要注意地是在這個例子中內存數據庫 SQLite 是被使用：盡管它是十分的快，但是你要是使用其它類型的數據庫(例如 MySQL 或者 PostgreSQL)，可能上述代碼就不適用。你也可能想要在 `setUp()` 里為你的數據庫增加一組實例一旦你的數據庫的表已經創建。如果你想要使用數據集的話，請參看 [Fixture](http://farmdev.com/projects/fixture/index.html)，它包含了對 SQLAlchemy 的支持。 ## 運行測試用例 ### 使用 unittest 一開始我建議把所有的測試放在一個文件里面，這樣你可以使用 `unittest.main()` 函數。這個函數將會發現在你的 `TestCase` 類里面的所有的測試方法。請記住，所有的測試方法和類請以 `test` 開頭（不區分大小寫），這樣才能被自動識別出來。一個測試用例的文件可以看起來像這樣: ``` import unittest import flask.ext.testing # your test cases if __name__ == '__main__': unittest.main() ``` 現在你可以用 `python tests.py` 命令執行你的測試。 ### 使用 nose 同樣 [nose](http://nose.readthedocs.org/en/latest/) 也與 Flask-Testing 能夠很好的融合在一起。 ## 更新歷史 ### 0.4.2 (24.07.2014) > > > * Improved teardown to be more graceful. > * Add `message` argument to `assertStatus` respectively all assertion methods with fixed status like `assert404`. > > ### 0.4.1 (27.02.2014) This release is dedicated to every contributer who made this release possible. Thank you very much. > > > * Python 3 compatibility (without twill) > * Add `LiveServerTestCase` > * Use unittest2 backports if available in python 2.6 > * Install multiprocessing for python versions earlier than 2.6 > > ### 0.4 (06.07.2012) > > > * Use of the new introduced import way for flask extensions. Use `import flask.ext.testing` instead of `import flaskext.testing`. > * Replace all `assert` with `self.assert*` methods for better output with unittest. > * Improved Python 2.5 support. > * Use Flask’s preferred JSON module. > > ## API `class flask.ext.testing.TestCase(methodName='runTest')` `assert200(response)` Checks if response status code is 200 Parameters: **response** – Flask response `assert400(response)` Checks if response status code is 400 Versionadded: 0.2.5 Parameters: **response** – Flask response `assert401(response)` Checks if response status code is 401 Versionadded: 0.2.1 Parameters: **response** – Flask response `assert403(response)` Checks if response status code is 403 Versionadded: 0.2 Parameters: **response** – Flask response `assert404(response)` Checks if response status code is 404 Parameters: **response** – Flask response `assert405(response)` Checks if response status code is 405 Versionadded: 0.2 Parameters: **response** – Flask response `assert500(response)` Checks if response status code is 500 Versionadded: 0.4.1 Parameters: **response** – Flask response `assertContext(name, value)` Checks if given name exists in the template context and equals the given value. Versionadded: 0.2 Parameters: * **name** – name of context variable * **value** – value to check against `assertRedirects(response, location)` Checks if response is an HTTP redirect to the given location. Parameters: * **response** – Flask response * **location** – relative URL (i.e. without **http://localhost**) `assertStatus(response, status_code)` Helper method to check matching response status. Parameters: * **response** – Flask response * **status_code** – response status code (e.g. 200) `assertTemplateUsed(name, tmpl_name_attribute='name')` Checks if a given template is used in the request. Only works if your version of Flask has signals support (0.6+) and blinker is installed. If the template engine used is not Jinja2, provide `tmpl_name_attribute` with a value of its `Template` class attribute name which contains the provided `name` value. Versionadded: 0.2 Parameters: * **name** – template name * **tmpl_name_attribute** – template engine specific attribute name `assert_200(response)` Checks if response status code is 200 Parameters: **response** – Flask response `assert_400(response)` Checks if response status code is 400 Versionadded: 0.2.5 Parameters: **response** – Flask response `assert_401(response)` Checks if response status code is 401 Versionadded: 0.2.1 Parameters: **response** – Flask response `assert_403(response)` Checks if response status code is 403 Versionadded: 0.2 Parameters: **response** – Flask response `assert_404(response)` Checks if response status code is 404 Parameters: **response** – Flask response `assert_405(response)` Checks if response status code is 405 Versionadded: 0.2 Parameters: **response** – Flask response `assert_500(response)` Checks if response status code is 500 Versionadded: 0.4.1 Parameters: **response** – Flask response `assert_context(name, value)` Checks if given name exists in the template context and equals the given value. Versionadded: 0.2 Parameters: * **name** – name of context variable * **value** – value to check against `assert_redirects(response, location)` Checks if response is an HTTP redirect to the given location. Parameters: * **response** – Flask response * **location** – relative URL (i.e. without **http://localhost**) `assert_status(response, status_code)` Helper method to check matching response status. Parameters: * **response** – Flask response * **status_code** – response status code (e.g. 200) `assert_template_used(name, tmpl_name_attribute='name')` Checks if a given template is used in the request. Only works if your version of Flask has signals support (0.6+) and blinker is installed. If the template engine used is not Jinja2, provide `tmpl_name_attribute` with a value of its `Template` class attribute name which contains the provided `name` value. Versionadded: 0.2 Parameters: * **name** – template name * **tmpl_name_attribute** – template engine specific attribute name `create_app()` Create your Flask app here, with any configuration you need. `get_context_variable(name)` Returns a variable from the context passed to the template. Only works if your version of Flask has signals support (0.6+) and blinker is installed. Raises a ContextVariableDoesNotExist exception if does not exist in context. Versionadded: 0.2 Parameters: **name** – name of variable `class flask.ext.testing.Twill(app, host='127.0.0.1', port=5000, scheme='http')` Versionadded: 0.3 Twill wrapper utility class. Creates a Twill `browser` instance and handles WSGI intercept. Usage: ``` t = Twill(self.app) with t: t.browser.go("/") t.url("/") ``` `url(url)` Makes complete URL based on host, port and scheme Twill settings. Parameters: **url** – relative URL `class flask.ext.testing.TwillTestCase(methodName='runTest')` Deprecated: use Twill helper class instead. Creates a Twill `browser` instance and handles WSGI intercept. `make_twill_url`<big>(</big>_url_<big>)</big> Makes complete URL based on host, port and scheme Twill settings. Parameters: **url** – relative URL