Add 740 total tests (up from ~200) covering:
- Compile-time interface compliance for all providers
- GetCapabilities assertions for every provider
- Parse function edge cases: empty, malformed, single-entry, multi-entry
- apt: extract inline parse logic into testable functions (parsePolicyCandidate,
parseUpgradeSimulation, parseHoldList, parseOwner, parseSourcesLine)
- dnf/rpm: edge cases for both dnf4 and dnf5 parsers, normalize/parseArch
- pacman/aur: parseUpgrades, parseGroupPkgSet, capabilities
- apk: parseUpgradeSimulation, parseListLine, SupportsDryRun
- flatpak/snap: semverCmp, stripNonNumeric edge cases
- pkg/ports: all parse functions with thorough edge cases
Every provider now has:
- Interface compliance checks (what it implements AND what it doesn't)
- Capabilities test via snack.GetCapabilities()
- Parse function unit tests with table-driven edge cases
pkg implements Manager, VersionQuerier, Cleaner, and FileOwner interfaces
wrapping FreeBSD's pkg(8) CLI. ports implements Manager wrapping OpenBSD's
pkg_add/pkg_delete/pkg_info tools.
Both use build tags (freebsd/openbsd) for real implementations with stub
files for other platforms. Includes parser tests for all output formats.