From 76b6f696133ec6a45269ca3d8f4639a6402e18b2 Mon Sep 17 00:00:00 2001
From: Marcel Otto <marcelotto@gmx.de>
Date: Sun, 17 May 2020 00:01:18 +0200
Subject: [PATCH] Fix raised BEAM error warning when namespace resolving
 top-level modules

---
 CHANGELOG.md                            | 5 +++++
 lib/rdf/namespace.ex                    | 8 ++++++++
 test/unit/vocabulary_namespace_test.exs | 6 ++++++
 3 files changed, 19 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index f49cd14..50a524f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,6 +13,11 @@ This project adheres to [Semantic Versioning](http://semver.org/) and
 - `RDF.Namespace.resolve_term/1` now returns ok or error tuples, but a new function 
   `RDF.Namespace.resolve_term!/1` with the old behaviour was added
 
+### Fixed
+
+- BEAM error warnings when trying to use top-level modules as vocabulary terms 
+
+
 [Compare v0.7.1...HEAD](https://github.com/marcelotto/rdf-ex/compare/v0.7.1...HEAD)
 
 
diff --git a/lib/rdf/namespace.ex b/lib/rdf/namespace.ex
index 8b70ad1..24084fe 100644
--- a/lib/rdf/namespace.ex
+++ b/lib/rdf/namespace.ex
@@ -73,6 +73,14 @@ defmodule RDF.Namespace do
 
   defp do_resolve_term(RDF, term), do: do_resolve_term(RDF.NS.RDF, term)
 
+  defp do_resolve_term(Elixir, term) do
+    {:error,
+      %RDF.Namespace.UndefinedTermError{message:
+        "#{term} is not a RDF.Namespace; top-level modules can't be RDF.Namespaces"
+      }
+    }
+  end
+
   defp do_resolve_term(namespace, term) do
     is_module =
       case Code.ensure_compiled(namespace) do
diff --git a/test/unit/vocabulary_namespace_test.exs b/test/unit/vocabulary_namespace_test.exs
index 7506529..f95df60 100644
--- a/test/unit/vocabulary_namespace_test.exs
+++ b/test/unit/vocabulary_namespace_test.exs
@@ -752,6 +752,12 @@ defmodule RDF.Vocabulary.NamespaceTest do
     assert_raise RDF.Namespace.UndefinedTermError, fn -> RDF.iri(ExUnit.Test) end
   end
 
+  test "resolving an top-level module" do
+    assert_raise RDF.Namespace.UndefinedTermError,
+                 "ExUnit is not a RDF.Namespace; top-level modules can't be RDF.Namespaces",
+                 fn -> RDF.iri(ExUnit) end
+  end
+
   test "resolving an non-existing RDF.Namespace module" do
     assert_raise RDF.Namespace.UndefinedTermError, fn -> RDF.iri(NonExisting.Test) end
   end