What causes tests that hit a real network or backend?

The code under test makes real HTTP or socket calls, so the test fails when the server is down, slow, or returns changing data, and it cannot run offline.

How do I catch this when it only happens for some players?

Capture it automatically from the player's device with the full stack trace, the device and OS, the build, and a breadcrumb trail of what they did. That turns a vague complaint into a specific, reproducible issue you can fix without owning the hardware it happens on.

How to Fix Tests That Hit a Real Network or Backend

Quick answer: Abstract the network behind an interface and inject a fake that returns canned responses in tests, reserving real calls for a small set of integration tests.

Unit tests should not depend on a live backend. Hiding the transport behind an interface lets you inject a deterministic fake, making the tests fast, offline, and stable.

How to fix it

1. Abstract the transport

Have the system depend on an interface like IApiClient rather than constructing an HTTP client directly, so the test can supply a substitute.

2. Inject a fake with canned responses

In tests pass a fake that returns fixed payloads and lets you simulate timeouts and 500s, so error handling is tested without an actual server.

3. Keep a few real integration tests

Tag a small suite that hits a real (staging) backend and run it separately, so contract drift is still caught without making every unit test network-bound.

Catching the ones you can't reproduce

The hardest version of this to fix is the one you can't reproduce — it only happens on a player's hardware, OS, driver, or save state, under conditions that simply aren't present on your machine. A report that says “it crashed” or “it froze” gives you nothing to act on, so the bug survives release after release while quietly costing you players.

Automatic error capture closes that gap. Each failure arrives with its full stack trace, the device and OS, the build number, and a breadcrumb trail of what the player did right before it broke, so even a failure you have never seen becomes a specific, reproducible issue. Fold identical failures into one signature ranked by how many players each hits, and your worklist sorts itself worst-first instead of arriving as a stream of vague complaints.

This is where a tool like Bugnet earns its place. Its SDK captures every error automatically with the full stack trace plus device, OS, memory, build, and game-state context, folds duplicates into one grouped issue with an occurrence count, and ties each to the build it first appeared on — so you fix the problem that hurts the most players first and confirm it is gone when its signature disappears from the next release.

Ship the fix, watch the signature disappear from the next build. That's how you know it's really gone.