broaden /metadata/:class tests; narrow 404 test to bogus-only names

- Extend `test_metadata_route_renders_for_model_class` to loop over
  `Ontology`, `Metrics`, `Class` — covers plain top-level lookup
  (`Ontology`), singularization (`Metrics` → `Metric`), and a second
  plain case with a distinctive name (`Class`). All three hit the same
  `resolve_model_class` top-level branch, but `Ontology` was the one
  case we previously had no explicit coverage for.

- Rename `test_metadata_route_returns_404_for_non_class_names` →
  `test_metadata_route_returns_404_for_bogus_names` and trim its list
  to `DefinitelyNotAModel`, `nonexistent_thing`, `xyzqux123` —
  guaranteed-nonexistent identifiers that will stay 404 regardless of
  future features.

  The previous list (`created`, `body`, `prefixIRI`, `name`,
  `omvacronym`) was misleading: those *are* attribute URIs the API
  emits in JSON-LD @context, currently 404'd as a stop-gap but tracked
  in ncbo/bioportal-project#388 for actual attribute-documentation
  rendering. Leaving them asserted as 404 would turn into a false
  regression signal when #388 lands.

Author: alexskr

test/controllers/test_home_controller.rb

@@ -29,9 +29,12 @@ def test_documentation_route_renders
   # for the same namespace-helper-resolution reason as /documentation, and
   # had been listed as broken in #37 since 2017.
   def test_metadata_route_renders_for_model_class
-    get '/metadata/Metrics'
-    assert last_response.ok?, get_errors(last_response)
-    assert_match(/<html/i, last_response.body)
+    %w[Ontology Metrics Class].each do |name|
+      get "/metadata/#{name}"
+      assert last_response.ok?,
+        "expected 200 for /metadata/#{name}, got #{last_response.status}: #{get_errors(last_response)}"
+      assert_match(/<html/i, last_response.body)
+    end
   end
 
   # Exercises the sub-module lookup branch in HomeHelper#routes_by_class
@@ -42,11 +45,19 @@ def test_metadata_route_resolves_submodule_class
     assert_match(/<html/i, last_response.body)
   end
 
-  # /metadata/:class for names that aren't model classes (attribute/property
-  # names, arbitrary typos) should return 404, not 500. Several paths of this
-  # shape are listed in ncbo/ontologies_api#37.
-  def test_metadata_route_returns_404_for_non_class_names
-    %w[created body prefixIRI name omvacronym Nonexistent].each do |name|
+  # /metadata/:class for genuinely bogus names (arbitrary typos, identifiers
+  # not emitted by the API anywhere) should always return 404.
+  #
+  # Attribute URIs that the API *does* emit in JSON-LD @context (e.g.
+  # /metadata/created, /metadata/name, /metadata/prefixIRI, /metadata/omv*)
+  # are intentionally NOT asserted here. Those currently 404 as a stop-gap
+  # (commit d2e5b64), but ncbo/bioportal-project#388 tracks making them
+  # render actual attribute documentation. When that lands this test should
+  # not silently flip from "correctly 404" to "incorrectly 404 — feature
+  # regressed"; a new assertion covering attribute URIs will live alongside
+  # that feature work instead.
+  def test_metadata_route_returns_404_for_bogus_names
+    %w[DefinitelyNotAModel nonexistent_thing xyzqux123].each do |name|
       get "/metadata/#{name}"
       assert_equal 404, last_response.status,
         "expected 404 for /metadata/#{name}, got #{last_response.status}: #{last_response.body[0, 200]}"