Google/Bing/DuckDuckGo/Qwant were tested as a way to find prices on the
3 remaining requested merchants and all four block scraping immediately
(visible captcha or JS-only anti-bot challenge on the very first
automated request) - not usable as an intermediary. Instead, a headless
browser was used to scrape these 3 merchants directly, since their
blocking (JS-only search, empty body, 403) turned out to be bypassable
with real browser rendering rather than needing to get past a captcha:
- Materiel.net: search is entirely client-side (Stimulus/Turbo), a plain
GET on /recherche/?query=... always returns the empty "no results"
template. Fixed by actually filling the search input and clicking
submit in a real page.
- Cdiscount: returns a fully empty response body to plain HTTP fetches
(no error, just nothing) but renders fine in a real browser.
- PCComponentes: blocks plain HTTP requests with a 403, but a headless
browser with a normal user agent goes through.
Implementation:
- New playwright-core dependency, pointed at a system-installed
Chromium binary via CHROMIUM_EXECUTABLE_PATH (set to /usr/bin/chromium
here) instead of downloading Playwright's own ~300MB browser
- New headless_browser_service.ts: lazily launches a single shared
Chromium instance reused across lookups (avoids paying browser launch
cost per request), with a withPage() helper that always closes its
browser context afterwards. A new start/browser.ts preload registers
an app.terminating() hook so the browser process is closed on shutdown
instead of leaking a child process.
- fetchMaterielNetPrice/fetchCdiscountPrice/fetchPcComponentesPrice
follow the same model-token matching strategy as the existing
cheerio-based merchants (LDLC/Grosbill/TopAchat): search on a short
brand+series query, then pick the result whose label/attribute
contains the extracted model number, to avoid misreporting an
unrelated product's price
- PCComponentes exposes clean data-product-price/data-product-category
attributes directly on result links, so full pre-built "Sobremesa" PCs
that happen to mention the searched CPU are excluded rather than
reported as its price
- Fixed two bugs found while testing with a Ryzen 5 9600X (a case with
multiple search results, unlike the Ryzen 3 3200G single-redirect case
used earlier):
- Materiel.net: a search results list page also has .o-product__price
elements (one per card), so checking for their mere presence isn't
enough to detect the "redirected to a single product" case; now
disambiguated by URL pattern (/produit/ vs /recherche/)
- New parseFlattenedFragmentedPriceText(): Playwright's innerText()
flattens "<whole>€<sup>cents</sup>" prices to plain strings like
"284€95" or "2 049€95", which the existing parser misread as
28495/204995. Cheerio-based scrapers (LDLC/Grosbill) already handled
this correctly via DOM structure (parseFragmentedPrice); this adds
the equivalent for already-flattened text.
- findCheapestOffers() now queries all 7 merchants in parallel
- Extended the MerchantOffer type/favicon domain map on the frontend for
the 3 new merchants
All 30 existing tests still pass unchanged (they don't exercise live
network scraping, only the surrounding auth/validation/caching logic).
Kevin L'Hereec