tegwick
44faf3de8e
Two decisions taken with the operator: stdlib HTML driver instead of Playwright (F-0004), and a deterministic discovery runtime instead of a live model. Both sit behind interfaces so the alternatives drop in later. - html.py: stdlib DOM parse and query - agentic.py: DiscoveryRuntime (agentic arm, ignores data-td by construction) and RecordedSelectorRuntime (control arm, uses the strongest identifier the page offers) - browser.py: per-actor sessions over real HTTP, constructed per call so no actor inherits another's connection state - cost/nondeterminism metrics recorded from the first run F-0005 (CONCEPT_DRIFT): the H-001 result is a narrowing. Where test ids are preserved, discovery 9/9 and recorded selectors 9/9 - the semantic action buys nothing. Where they are dropped, discovery 2/3 and recorded 0/3. The concept model presents semantic actions as generally superior; the evidence says conditionally superior. M21 and M22 added mid-task: the deciding side of the axis was N=1. M22 (field names renamed) defeats the heuristic and is the first concrete evidence that a live model would add capability, not just cost. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Assistant: claude-code Assistant-Model: opus Assistant-Process: 1629012@bnt-lap001 Assistant-Session: 78d4fb13-8a1e-474b-87a3-9b9261c49a39
2.4 KiB
| id | type | class | status | discovered | discovered_by | workplan | task | carried_to |
|---|---|---|---|---|---|---|---|---|
| F-0004 | framework-finding | FRAMEWORK_LIMITATION | open | 2026-08-22 | TD-WP-0002-T07 | TD-WP-0002 | TD-WP-0002-T07 | TD-WP-0002-T10 |
F-0004 — The browser surface is driven without a browser
Decision
TD-WP-0002-T07 names Playwright as the browser driver. It was not used.
Instead, src/testdriver/html.py parses the lab's server-rendered HTML with
html.parser, and src/testdriver/browser.py drives it over real HTTP.
Reasons, in order of weight:
- The lab's surface has no JavaScript. It is server-rendered forms. A browser engine would not change what H-001 or H-002 can be measured against — the mutations that matter are DOM restructuring, rewording and field renaming, all of which a parser faces in full.
- Establishing Playwright is a real cost to the operator — installation plus a licence review, and the usual snag is the Chromium binaries the installer pulls rather than the library licence itself. Blocking the vertical spike on that was not worth it for a surface that gains nothing from it.
- The stack is deliberately boring. Zero dependencies remains true.
Driver is a Protocol, so a Playwright implementation sits alongside this one
without touching the kernel, the oracles or the evidence format.
What this costs — stated, not buried
The driver cannot:
- execute JavaScript, so no single-page-application surface can be driven;
- take screenshots, so that evidence type listed in
INTENT.mdis unavailable; - read an accessibility tree, or observe visual layout at all.
The third is the most consequential for the thesis. A real mechanical change often moves a control visually while leaving the DOM largely intact, and this driver is blind to that entire class. H-001's mutation set is therefore narrower than the hypothesis's wording implies: it tests structural durability, not visual durability.
That should be said plainly whenever the H-001 result is quoted.
Carried to T10
Two questions, neither answerable now:
- Does a Playwright driver actually change the H-001 result, or merely widen the surface it can reach? Worth one experiment, not a rewrite.
- Is the screenshot evidence type in
INTENT.mdload-bearing, or was it listed because screenshots are conventional in this space? If nothing has needed one by T10, that is a candidate for compression.