verification chain

The word "chain" is doing real work in the phrase. The checks run in a fixed order, each one gates the next, and a failure anywhere stops the sequence rather than being noted and passed over. A tool that runs some checks sometimes has automated testing. A tool that runs the same checks in the same order on every build, and releases nothing until they pass, has a verification chain.

In sup3rapp the chain has four stages — a typecheck, the test suite, a production build, and a smoke test — run inside the project's own sandbox. The order is chosen so the cheapest, most precise check runs first: a typecheck fails in seconds and names a file and a line, where a smoke test fails later and tells you only that something did not start.

A verification chain proves less than people assume. It proves the code is internally consistent, that existing tests still pass, that it builds under production settings, and that it starts. It does not prove the app does what you meant, and it is not a security review. The value is narrower and still large: it removes the entire class of failure where you are handed something that was never run.

When a stage fails, what happens next is a repair loop.