Fix Atom category attribute parsing

[cardmagic]

Atom categories store their value in term, but the parser read element text and lost ordinary self-closing categories. Read Atom 1.0 terms so scalar category, array_tags: [:category], and items_by_category work together. Preserve source order and duplicates, skip missing or blank terms, and retain RSS category text, CDATA, and scalar/array behavior.

Resolve default and prefixed namespaces at each entry's actual position in the feed, including local overrides and resets. Keep category extraction within direct children so nested content, source metadata, comments, and neighboring entries cannot supply a category. Reuse the existing link tokenizer for direct-child extraction while retaining relation-link behavior and zero additional runtime dependencies. Update the README and Unreleased changelog.

Validation: the initial regression failed with expected ["ruby", "rails"] and actual nil; it passes after the fix. Added separate failing regressions for namespace declarations in comments and namespace leakage from an RDF channel to sibling items. The full suite passes on Ruby 3.4.8 (136 tests, 310 assertions; 3 existing network-test omissions), along with RuboCop, RBS generation/validation, and Steep. Category values also match namespace-aware XML extraction for all three entries in the archived fork fixture.

Review note: Hound reports single-quote style and test length/complexity limits from its defaults. The repository explicitly requires double quotes and excludes tests from those metrics in .rubocop.yml; the configured CI lint check passes. Those conflicting Hound threads are resolved without changing the project conventions.

Closes #56.

[greptile-apps]

Greptile Summary

This PR updates category parsing to read Atom 1.0 term attributes while retaining RSS text and CDATA behavior.

• Restricts category extraction to direct item or entry children.
• Resolves inherited, overridden, and reset XML namespaces at each entry.
• Reuses direct-child tokenization for relation links and category extraction.
• Adds regression coverage for scalar and array categories, filtering, namespace scope, ordering, duplicates, and nested metadata exclusion.
• Documents the behavior in the README and Unreleased changelog.

Confidence Score: 5/5

The PR appears safe to merge, with no concrete correctness, security, or independently actionable quality issue identified.

The new parser preserves existing relation-link and RSS category behavior while adding focused Atom namespace and term handling backed by boundary and regression coverage.

Important Files Changed

Filename	Overview
lib/simple-rss.rb	Adds namespace-aware direct-child category extraction and factors relation-link scanning through the shared child-element tokenizer.
test/base/category_parsing_test.rb	Adds comprehensive regressions for Atom terms, RSS compatibility, namespace scoping, nested-element exclusion, ordering, duplicates, and filtering.
test/data/atom_categories.xml	Provides Atom category fixtures covering attributes, entities, duplicates, blank terms, and prefixed categories.
test/data/rss_categories.xml	Provides RSS category fixtures covering text, CDATA, duplicates, scalar behavior, and arrays.
README.md	Documents Atom term extraction, RSS compatibility, category filtering, and namespace behavior.
CHANGELOG.md	Records the category parsing fix and its compatibility guarantees under Unreleased.

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
  A[Scan feed for item or entry] --> B[Resolve namespace context at entry position]
  B --> C[Inspect configured item tags]
  C -->|category| D[Tokenize direct child elements]
  D --> E{Category namespace}
  E -->|Atom 1.0| F[Read and normalize term attribute]
  E -->|RSS namespace| G[Read element text or CDATA]
  E -->|Foreign or undeclared prefix| H[Skip category]
  F --> I[Apply scalar or array behavior]
  G --> I
  I --> J[Populate item category]
  C -->|other tag| K[Use existing item-tag parser]

Loading

_{Reviews (1): Last reviewed commit: "fix: parse Atom category terms" | Re-trigger Greptile}