How I check that my Rust port still does what the Go original does

A developer built cliproxy-rs, a Rust port of the Go proxy CLIProxyAPI, and paired it with a source-extracted parity audit that tracks each Go contract as covered, partial or missing. The checklist is generated from the Go source at a pinned commit (v8.0.35 yields 1,951 items), with a Python script (audit.py) matching recorded Go fixtures to Rust tests and a second script probing which method/path pairs actually route. The latest audit reports 1,053 covered, 872 partial and 26 missing, after a manual pass over 833 non-covered items moved 164 statuses, including 13 downgrades from covered to partial when the scanner was found to accept a fixture hitting the same path with a different HTTP method.

cliproxy-rs is my Rust port of CLIProxyAPI, a Go proxy that puts Claude, Codex, Gemini and OpenAI-compatible APIs behind one local endpoint. The promise is that a Go user can point the Rust binary at their existing config.yaml and credential files and get the same routes and the same answers. Trying requests by hand only tells you the requests you tried work. I wanted a coverage number I could trace back to evidence, item by item. A list I wrote by hand would only contain the things I remembered, so the checklist is extracted from the Go source at a pinned commit. Each item is one contract: a Go test file, a config key, a public or management route, a plugin RPC method, a CLI flag. At Go v8.0.35 that's 1,951 items. The biggest groups: | Kind | Items | |---|---| | Go test-suite files | 989 | | Config leaves | 436 | | Management routes | 186 | | Public routes | 77 | | Plugin RPC methods | 62 | | CLI flags | 34 | Every item gets one of three statuses: A Python script audit.py fills in most of it. Fixtures recorded from Go carry the Go test name and line, so it can match each Go test against the names cited in Rust tests and fixtures. A second script starts the server and records which method and path pairs actually route. When the scan gets something wrong I override it in a TSV, one row per item, with the evidence and a note. When I redid the audit for v0.2.6, the generated numbers were 854 covered, 722 partial, 111 missing. The README said 835 / 707 / 145, so it was already stale. I went through all 833 items that weren't covered and 164 changed status. Most moved up 73 partial to covered, 36 missing to covered, 42 missing to partial . 13 went from covered down to partial, and those were the useful ones. The scanner had counted a route as covered when a fixture hit the same path, even with a different HTTP method, so a GET test was vouching for a POST handler. Now the evidence has to match the method and the complete route. Two more rules came out of that pass. A subsystem that works doesn't make a whole Go test suite covered: Go has 23 Claude alias-restoration cases, I replay 20, so that item is partial. And a Go test name in a Rust comment is a search hint. It doesn't prove the assertions were ported. Go keeps shipping. I'd been comparing against v8.0.10, and moving to v8.0.35 meant going through 288 upstream commits and adding 264 checklist items. I kept all 1,687 existing IDs and appended the new ones at the end of each section, so branches I had in flight still point at the right item. Tests Go deleted are marked historical instead of disappearing. The last audit 20 Oct, against v8.0.35 reads 1,053 covered, 872 partial and 26 missing. Partial is the biggest bucket. It holds everything implemented in part or implemented without a test that pins Go's behaviour, and the audit won't round any of it up to covered. Generate the checklist from the original's source. Make "covered" need evidence a script can find, and make every manual override say why. My first honest pass moved 13 items backwards. The checklist, the scripts and the per-item notes are in the repo under docs/parity-audit : https://github.com/vayungodara/cliproxy-rs https://github.com/vayungodara/cliproxy-rs