test: use pytest fixture and simplify test code (laike9m#50)

Author: 100gle

tests/conftest.py

@@ -0,0 +1,31 @@
+"""
+In `conftest.py` we define fixtures that are used in multiple tests. pytest will automatically
+inject them into the test functions that need them by signature matching.
+"""
+
+
+from pathlib import Path
+
+import pytest
+from flask.testing import FlaskClient
+
+from app import app
+
+CHALLENGES_DIR = Path(__file__).parent.parent / "challenges"
+ALL_QUESTIONS = list(CHALLENGES_DIR.glob("**/question.py"))
+ALL_SOLUTIONS = list(CHALLENGES_DIR.glob("**/solution.py"))
+
+
+@pytest.fixture
+def test_client() -> FlaskClient:
+    return app.test_client()
+
+
+@pytest.fixture(params=ALL_QUESTIONS, ids=lambda x: x.parent.name)
+def question_file(request):
+    return request.param
+
+
+@pytest.fixture(params=ALL_SOLUTIONS, ids=lambda x: x.parent.name)
+def solution_file(request):
+    return request.param

tests/fixture.py

@@ -1,30 +1,25 @@
 from pathlib import Path
 
-import pytest
-from werkzeug.test import TestResponse
-from app import app
-from .fixture import ALL_QUESTIONS
+from flask.testing import FlaskClient
 
 
-@pytest.mark.parametrize("question_file", ALL_QUESTIONS, ids=lambda x: x.parent.name)
-def test_get_challenge(question_file: Path):
+def test_get_challenge(test_client: FlaskClient, question_file: Path):
     level, challenge_name = question_file.parent.name.split("-", maxsplit=1)
-    response = app.test_client().get(f"/{level}/{challenge_name}")
+    response = test_client.get(f"/{level}/{challenge_name}")
 
     # Verify the returned HTML contains a challenge's source code
     assert "TODO" in response.text
 
 
-@pytest.mark.parametrize("question_file", ALL_QUESTIONS, ids=lambda x: x.parent.name)
-def test_run_challenge(question_file: Path):
+def test_run_challenge(test_client: FlaskClient, question_file: Path):
     level, challenge_name = question_file.parent.name.split("-", maxsplit=1)
-    response = app.test_client().post(f"run/{level}/{challenge_name}", data="")
+    response = test_client.post(f"run/{level}/{challenge_name}", data="")
 
     # Verify backend can run type check and return results
     assert response.json is not None
 
 
-def test_invalid_challenge_redirect_to_homepage():
-    response = app.test_client().get("/foo/bar")
+def test_invalid_challenge_redirect_to_homepage(test_client: FlaskClient):
+    response = test_client.get("/foo/bar")
     assert response.status_code == 302
     assert response.location == "/"

tests/test_api.py

@@ -4,13 +4,9 @@
 
 from pathlib import Path
 
-import pytest
-
 from views.challenge import Challenge, Level
-from .fixture import ALL_SOLUTIONS, QUESTION
 
 
-@pytest.mark.parametrize("solution_file", ALL_SOLUTIONS, ids=lambda x: x.parent.name)
 def test_identical(solution_file: Path):
     level, challenge_name = solution_file.parent.name.split("-", maxsplit=1)
     with solution_file.open() as f:
@@ -19,7 +15,7 @@ def test_identical(solution_file: Path):
         name=challenge_name, level=Level(level), code=solution_code
     ).test_code
 
-    question_file = solution_file.parent / QUESTION
+    question_file = solution_file.parent / "question.py"
     with question_file.open() as f:
         question_code = f.read()
     question_test = Challenge(

tests/test_identical.py

@@ -7,10 +7,8 @@
 import pytest
 
 from views.challenge import ChallengeManager
-from .fixture import ALL_QUESTIONS
 
 
-@pytest.mark.parametrize("question_file", ALL_QUESTIONS, ids=lambda x: x.parent.name)
 def test_solution_valid(question_file: Path):
     # Skip the challenges whose question can't fail type check no matter how many tests are added.
     if question_file.parent.name == "basic-any":

tests/test_questions.py

@@ -4,13 +4,9 @@
 
 from pathlib import Path
 
-import pytest
-
 from views.challenge import ChallengeManager
-from .fixture import ALL_SOLUTIONS
 
 
-@pytest.mark.parametrize("solution_file", ALL_SOLUTIONS, ids=lambda x: x.parent.name)
 def test_solution_valid(solution_file: Path):
     with solution_file.open() as f:
         code = f.read()