npm metadata rewriting depended on handler.Proxy, which pulls SQL
drivers, cloud SDKs and metrics into its import graph. Move the
transformation into internal/metadata/npm with explicit policy,
evaluation time, public URL and hosted-version inputs, and share the
JSON scanner between npm and Composer through internal/jsonscan.
Rebased onto main: rewritten tarball URLs are still logged once per
document, now through an OnTarballsRewritten callback that reports the
count.
The Helm index.yaml and PyPI simple pages and JSON API documents were
parsed and rewritten on every request, cache hits and conditional
requests included. They now go through the rewrite cache like npm and
Composer, so a repeat request is served from memory with an ETag of
its own, a dated Last-Modified, a gzip copy and 304 when it matches.
PyPI simple pages are keyed by their content type and the versions
filtered out as well as the upstream page. Download hrefs are now
rewritten with a literal prefix search that makes the same changes as
the old regular expression, and the link filter's expressions are
compiled once.
A chart cache miss no longer parses the whole Helm index again while
the stored index is unchanged: the chart downloads it lists are kept
per repository, keyed by the index digest.
Denylist entries now also match Composer versions with Packagist's
leading v, OCI repositories written as a path, Swift registry packages
in either form (also when streaming), Go versions with escaped uppercase
letters, and gems whose names contain a dash followed by a digit. OCI
manifests are checked by tag and digest, and denied blobs and Swift
archives answer 403 instead of 500 or 502.
Denylist entries were compared as plain PURL strings, but handlers build
PURLs from download URLs that spell packages differently, so some denied
versions were still served. Entries and checked PURLs now go through one
per-ecosystem comparison form: PyPI names follow PEP 503 (case and runs of
-, _ and . are equivalent), NuGet ids and versions ignore case, a gem
version also matches its platform builds, and a conda entry matches the
package in every channel unless it carries a channel qualifier. Cache keys
are unchanged.
The denylist tests call NewDebianHandler with three arguments, but the
additional APT archives change gave it a fourth. Each passed CI on its
own branch, and together they leave internal/handler without a test
binary that compiles, so go vet and go test fail on main.
