feat: _registry_name_from_url helper for nvchecker autodetect

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

2 files changed, 50 insertions, 0 deletions

diff --git a/mkhint b/mkhint
index 6a0f157..7d4c505 100755
--- a/mkhint
+++ b/mkhint
@@ -817,6 +817,32 @@ _has_nvchecker_section() {
         "$NVCHECKER_CONFIG"
 }
 
+# Extract a package name from a language-registry download URL.
+# Args: <url> <prgnam-fallback>. Prints the parsed name, or the fallback
+# (PRGNAM) when no host-specific pattern matches.
+_registry_name_from_url() {
+    local url="$1" fallback="$2"
+    case "$url" in
+        *crates.io/api/v1/crates/*)
+            # .../crates/NAME/NAME-VER.crate  or  .../crates/NAME/VER/download
+            printf '%s' "${url#*crates.io/api/v1/crates/}" | cut -d/ -f1
+            return 0 ;;
+        *rubygems.org/downloads/*)
+            # /downloads/NAME-VER.gem
+            local base="${url##*/downloads/}"; base="${base%.gem}"
+            printf '%s' "${base%-*}"
+            return 0 ;;
+        *registry.npmjs.org/*)
+            # /NAME/-/NAME-VER.tgz   (NAME may be @scope/pkg)
+            printf '%s' "${url#*registry.npmjs.org/}" | sed 's|/-/.*||'
+            return 0 ;;
+        *hackage.haskell.org/package/*)
+            printf '%s' "${url#*hackage.haskell.org/package/}" | cut -d/ -f1
+            return 0 ;;
+    esac
+    printf '%s' "$fallback"
+}
+
 # Append an nvchecker [pkg] section to NVCHECKER_CONFIG, auto-detecting the
 # source from the package's .info DOWNLOAD/HOMEPAGE. No-op if section exists.
 add_nvchecker_section() {
diff --git a/tests/mkhint_test.sh b/tests/mkhint_test.sh
index 85d988d..e000820 100755
--- a/tests/mkhint_test.sh
+++ b/tests/mkhint_test.sh
@@ -1950,6 +1950,30 @@ echo "$arrow_line" | grep -q '0.26.7' && echo "$arrow_line" | grep -q '0.26.8' \
     || { echo "  FAIL: report versions. out=$rep"; (( FAIL++ )); ERRORS+=("T-BM21"); }
 rm -f "$MOCK_BASE/manifest_fixture" "$MOCK_HINT/nvim.hint"
 
+# ── T-NV1: _registry_name_from_url extracts names per host ────────────────────
+echo ""
+echo "T-NV1: _registry_name_from_url host-specific parsing"
+# Build a patched script we can source for unit-testing helpers
+SRC_PATCHED=$(mktemp /tmp/mkhint_src_XXXXXX)
+sed -e "s|REPO_DIR=\".*\"|REPO_DIR=\"$MOCK_REPO\"|" \
+    -e "s|HINT_DIR=\".*\"|HINT_DIR=\"$MOCK_HINT\"|" \
+    "$SCRIPT" > "$SRC_PATCHED"
+# shellcheck disable=SC1090
+source "$SRC_PATCHED"
+
+nv_out="$MOCK_BASE/nv_helper.txt"
+{
+  echo "crates $(_registry_name_from_url 'https://crates.io/api/v1/crates/ripgrep/ripgrep-14.0.0.crate' ripgrep)"
+  echo "gems $(_registry_name_from_url 'https://rubygems.org/downloads/rails-7.1.0.gem' rails)"
+  echo "npm $(_registry_name_from_url 'https://registry.npmjs.org/left-pad/-/left-pad-1.3.0.tgz' left-pad)"
+  echo "fallback $(_registry_name_from_url 'https://example.com/weird/path.tar.gz' mypkg)"
+} > "$nv_out"
+
+assert_contains "crates name parsed"   "$nv_out" '^crates ripgrep$'
+assert_contains "gems name parsed"     "$nv_out" '^gems rails$'
+assert_contains "npm name parsed"      "$nv_out" '^npm left-pad$'
+assert_contains "fallback to PRGNAM"   "$nv_out" '^fallback mypkg$'
+
 # ─── SUMMARY ──────────────────────────────────────────────────────────────────
 teardown