Integration test với pytest

test_roundtrip.py

from store import luu_json, tai_json    # cap luu/doc cua ban

def test_roundtrip(tmp_path):
    goc = {"id": 1, "tieu_de": "Hoc Python", "xong": True}
    f = tmp_path / "task.json"
    luu_json(goc, f)                     # serialize + ghi file
    lai = tai_json(f)                    # doc file + deserialize
    assert lai == goc                    # khu hoi phai khop

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1 passed in 0.01s

conftest.py + test_db.py

# conftest.py
import sqlite3, pytest

@pytest.fixture(scope="session")          # tao schema MOT lan
def con():
    c = sqlite3.connect(":memory:")
    c.execute("CREATE TABLE tasks(id INTEGER, tieu_de TEXT)")
    yield c
    c.close()

@pytest.fixture                           # MOI test: transaction roi rollback
def db(con):
    con.execute("BEGIN")
    yield con
    con.rollback()                        # bo moi thay doi -> test sau thay DB sach

# test_db.py
def test_them(db):
    db.execute("INSERT INTO tasks VALUES (?, ?)", (1, "Hoc"))
    (ten,) = db.execute("SELECT tieu_de FROM tasks WHERE id=?", (1,)).fetchone()
    assert ten == "Hoc"

def test_rong(db):
    assert db.execute("SELECT COUNT(*) FROM tasks").fetchone()[0] == 0   # khong thay du lieu test truoc

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2 passed in 0.02s

mock_vs_fake.py

from unittest.mock import MagicMock

# MOCK: kiem "co goi dung khong"
gui = MagicMock()
gui("an@x.com", "hi")
gui.assert_called_once_with("an@x.com", "hi")   # kiem TUONG TAC

# FAKE: ban cai don gian, kiem KET QUA
class HopThuFake:
    def __init__(self): self.da_gui = []
    def gui(self, to, body): self.da_gui.append((to, body))
ht = HopThuFake(); ht.gui("an@x.com", "hi")
assert ht.da_gui == [("an@x.com", "hi")]

test_net.py

import gia_service                       # co ham lay_gia() goi API that

def tong_tien(so_luong):
    return so_luong * gia_service.lay_gia()

def test_tong_tien(monkeypatch):
    # Thay lay_gia bang ban gia -> KHONG goi internet
    monkeypatch.setattr(gia_service, "lay_gia", lambda: 100)
    assert tong_tien(3) == 300

def test_doc_env(monkeypatch):
    monkeypatch.setenv("API_KEY", "test-key")   # thay bien moi truong tam thoi
    ...

..                                         [100%]
2 passed in 0.01s