tests.test_npm module

Tests for the npm registry client.

The shared fetch-and-cache mechanics behind _fetch_json are covered once in tests/test_http.py.

tests.test_npm.test_get_release_dates_maps_versions_to_dates()

Each version maps to its publication date, truncated to YYYY-MM-DD.

tests.test_npm.test_get_release_dates_empty_when_fetch_fails()

A failed metadata fetch degrades to an empty mapping.