[Solved] Why does this test client code raise an error?with app.test_client() as client: response = client.get('/missing_route')Assuming no route is defined for /missing_route. | Flask

Flask - Testing Flask Applications

Why does this test client code raise an error?

with app.test_client() as client:
    response = client.get('/missing_route')

Assuming no route is defined for /missing_route.

ARaises RuntimeError due to missing route

BRaises KeyError because route is missing

CNo error; response status will be 404

DRaises AttributeError on client.get()

Step-by-Step Solution

Solution:

Step 1: Understand test client behavior on missing routes
When a route is missing, Flask returns a 404 response but does not raise an error.
Step 2: Confirm no exceptions raised
Calling client.get() on a missing route returns a response with status 404, no exceptions.
Final Answer:
No error; response status will be 404 -> Option C
Quick Check:
Missing route returns 404 response, no error [OK]

Quick Trick: Missing routes return 404, not exceptions in test client [OK]

Common Mistakes:

MISTAKES

Master "Testing Flask Applications" in Flask

9 interactive learning modes - each teaches the same concept differently

More Flask Quizzes

Why does this test client code raise an error?