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mangaBookmark/docs/adr/0008-series-identity-is-discovered-not-derived.md
T
sulthan 0fe07d12f8 Record the lightnovelworld series-identity decision (#77)
A Series identity is discovered from the Site's own links, never derived
from an address. ADR-0008 carries the decision and the evidence behind
it: 3 of 41 sampled novels serve chapters under a slug that differs from
their series slug, one novel serves chapters under two, and neither slug
is computable from the other.

CONTEXT.md gains Chapter Slug as a term, defines it as plural by nature
and never an identity, and pins Series identity to the canonical slug the
Site publishes. Latest Chapter is restated as the highest-numbered
chapter rather than the newest-dated one, settling #79.

The research note is corrected in place where later probes refuted it:
the ul.clstyle container it named is the hidden empty "Latest Reading"
template rather than the chapter list, and its caveat about the comment
region understated the risk, since that region is writable by any
visitor and the scan takes an unbounded maximum into a shared row.

Docs only; no code. Implementation is specified in #80.
2026-08-11 09:28:26 +07:00

5.5 KiB
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ADR-0008: A Series identity is discovered from the Site's links, never derived from an address

Date: 2026-08-11 Status: accepted

Decision

On lightnovelworld, a Series is identified by the slug in its /novel/<slug>/ address, and the userscript obtains that address by reading the chapter page's a[aria-label="All Chapter"] anchor. It no longer constructs the address by string manipulation of the chapter path. When neither that anchor nor the microdata breadcrumb is present, the page resolves to type: "other" and no Bookmark is offered.

A Chapter Slug — the slug a chapter address is built from — is not an identity and is not stored. The backend finds chapters by matching lightnovelworld\.net/[a-z0-9-]+-chapter-([0-9.]+)/ against the series page body truncated at the first wpd-threads.

Why

Measured on lightnovelworld between 2026-08-10 and 2026-08-11.

The chapter slug and the series slug are two independent facts. In a 41-novel sample, 3 diverged (~7%). /my-longevity-simulation-chapter-1/ returns 200 while /novel/my-longevity-simulation/ returns 404 with no redirect, and that novel's real address is /novel/immortality-simulator/. Divergence runs in both directions: the-sword-illuminates-the-great-wilderness is served by chapter slug radiant-blade-of-the-wilderness. Neither slug is computable from the other, and the Site publishes no alternative-names field, so the mapping exists only in the chapter page's own markup.

Storing the Chapter Slug beside the identity does not work, because a Series may have more than one. /novel/all-jobs-and-classes-i-just-wanted-one-skill-not-them-all/ serves chapters 1–99 under …-one-skill-not and 100–423 under …-one-skill-not-them-all. Both resolve, and both chapter pages point back at the same Series.

Deriving the identity from the chapter path also made one Series produce two rows: bookmarking from the series page yielded lightnovelworld:immortality-simulator, and from a chapter page lightnovelworld:my-longevity-simulation.

The pointer is reliable. Across 8 chapter pages — chapter 1, chapter 1200, the latest chapter, both slugs of the split novel, two divergent novels, and a novel with a number in its title — the All Chapter anchor and breadcrumb position 2 were both present and agreed every time, including on the old-slug pages. Three narrower selectors were rejected on evidence: a[href*="/novel/"] matches the header nav index first; matching the text "All Chapter" false-matches the novel titled "…Not Them All Chapter 200"; and the JSON-LD breadcrumb's position 2 is the chapter, not the Series.

The scan is truncated because a series page server-renders a wpdiscuz comment thread below the chapter list, and comment bodies are HTML that can carry an anchor. Verified on /novel/the-sword-illuminates-the-great-wilderness/: comment #wpd-comm-358_0 rendered in the initial HTML, corroborated by that page's comment RSS feed. The scanner takes the maximum chapter number with no upper bound, and a Series row is shared by every Reader (ADR-0003), so one comment containing a link to a high-numbered chapter would pin that Series' Latest Chapter for everyone. wpd-threads occurs exactly once per page and follows every chapter anchor on all 4 series pages measured. wpdcom and wpdiscuz are unusable: they occur 111 to 143 times per page, including in <head> before the chapter list.

Considered options

Correct series_url only, leaving the Chapter Slug as the identity. This repairs the Poll with no migration, because the Poll reads the stored address rather than the identity. Rejected: it keeps an identity that the Site does not guarantee to be stable, and leaves the duplicate-row hazard in place.

Scope the match to the chapter-list container. Rejected on measurement. The prior research named ul.clstyle; on all 4 pages sampled that is the hidden, empty "Latest Reading" template, and the real list is a classless <ul> in div.eplister.eplisterfull. The backend scans raw HTML with no parser, so container extraction means a second regex against class names, which is more fragile than the one-off truncation and protects nothing extra.

Repair the stored rows with a SQL migration. Rejected as impossible: the database holds no source for the correct slug. The series table has no chapter address, and no endpoint on the Site maps one slug to the other.

Consequences

Existing Bookmarks on divergent novels stop matching their own chapter pages, because keyOf changes. The userscript therefore migrates a row in place when it sees the mismatch: it rewrites the row's key, identity and address in the cache, the retry-queue entry, and the last-checked map, then syncs. This heals only when the Reader next opens a chapter page of that novel.

A migrated row leaves its old series row behind. Nothing deletes it, but DueForLatestCheck is an inner join against bookmarks, so a Series with no Bookmarks is never polled again. The old row is permanently stored and permanently inert.

A Bookmark whose Reader never opens a chapter page of that novel does not heal. It continues to return 404 at every cooldown, as it does today.

If the truncation marker disappears, the scan is skipped and logged rather than run against the whole page. An env-gated live test, TestSmokeLnwCommentBoundary, asserts that wpd-threads still occurs exactly once and still follows the last chapter anchor. It skips when its environment variable is unset, matching the existing TestSmokeKagane* convention.