Testing the Go Port Against PHP

Fri, 23 Oct 2026 00:00:00 +0000

A Go function can return the same failure code as the PHP function and still behave differently in the application. Laravel might replace the exception before the PHP resolver sees it. A database reader might fail while loading a relationship that a direct unit test supplied as an already populated struct. Neither difference appears in a test which compares only the final price.

The rating engine’s migration checks therefore needed more than translated assertions. They needed executable observations from PHP, a clear point at which to compare them with Go, and enough detail to explain a disagreement. Otherwise, “the implementations match” could mean little more than “both tests contain the same assumption.”

A PHP Test File Isn't One Migration Case

Tue, 01 Sep 2026 00:00:00 +0000

One PHP file contained two test bodies and eleven migration cases. Counting it as one file would hide ten of them. Counting its two it(...) declarations would still miss most of the work. Copying the first assertion into a Go test would look plausible and preserve almost nothing of the original matrix.

The file covered customer lifecycle states in the pricing application. One body tested eight transitions; another tested three sets of state predicates. It was small enough to follow completely, which makes it a useful way into the much larger problem: using an existing PHP suite to constrain a Go port without pretending that translating test syntax proves equivalent behavior.

Php on Brian Faust

Testing the Go Port Against PHP

A PHP Test File Isn't One Migration Case