CollatrEdge has 800+ tests. More lines of test code than production code.
That is deliberate.
The E2E suite runs a full pipeline: real config parsing, real plugin instantiation, real data flow from input to output. The sustained operation tests run thousands of metrics through the system and verify nothing leaks, nothing drifts, nothing silently drops.
The buffer overflow tests fill the store-and-forward queue past capacity and verify the system degrades gracefully. Old data drops. New data keeps flowing. The agent stays up.
The error resilience tests inject failures at every layer. A processor that throws. An output that refuses connections. A corrupt SQLite file. The agent recovers from all of them.
We also tested a midnight UTC boundary bug that only triggers when timestamps span a day rotation. Found it in independent review. Would have been invisible in normal testing.
Manufacturing software does not get to crash. The production line keeps running whether your code is ready or not.