From fe49c0e43145820197add8d446571154b9d304d3 Mon Sep 17 00:00:00 2001
From: Marcel Otto <marcelotto@gmx.de>
Date: Thu, 8 Aug 2019 22:26:07 +0200
Subject: [PATCH] Move base IRI coercion from PrefixMap into new
 RDF.IRI.coerce_base/1

- and extend it to also support terms from vocabulary namespaces
---
 CHANGELOG.md                  |  4 ++++
 lib/rdf/iri.ex                | 19 +++++++++++++++++
 lib/rdf/prefix_map.ex         | 16 ++------------
 test/unit/iri_test.exs        | 39 ++++++++++++++++++++++++++++++++++-
 test/unit/prefix_map_test.exs |  2 +-
 5 files changed, 64 insertions(+), 16 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 15c6b0f..78f1acd 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,6 +13,8 @@ This project adheres to [Semantic Versioning](http://semver.org/) and
   option on `RDF.Graph.new` or the the new functions `RDF.Graph.set_base_iri/2` 
   and `RDF.Graph.clear_base_iri/1`
 - `RDF.Graph.clear_metadata/1` which clears the base IRI and the prefixes
+- `RDF.IRI.coerce_base/1` which coerces base IRIs; as opposed to `RDF.IRI.new/1`
+  it also accepts bare `RDF.Vocabulary.Namespace` modules
 
 
 ### Changed
@@ -24,6 +26,8 @@ This project adheres to [Semantic Versioning](http://semver.org/) and
 	- from the `base_iri` field of the given graph
 	- from the `RDF.default_base_iri` returning the one from the application 
 	  configuration
+- `RDF.PrefixMap.new` and `RDF.PrefixMap.add` now also terms from 
+  `RDF.Vocabulary.Namespace`s as namespaces
 
 
 [Compare v0.6.1...HEAD](https://github.com/marcelotto/rdf-ex/compare/v0.6.1...HEAD)
diff --git a/lib/rdf/iri.ex b/lib/rdf/iri.ex
index a614c7f..bc8bbe8 100644
--- a/lib/rdf/iri.ex
+++ b/lib/rdf/iri.ex
@@ -65,6 +65,25 @@ defmodule RDF.IRI do
   def new!(%RDF.IRI{} = iri),          do: valid!(iri)
 
 
+  @doc """
+  Coerces an IRI serving as a base IRI.
+
+  As opposed to `new/1` this also accepts bare `RDF.Vocabulary.Namespace` modules
+  and uses the base IRI from their definition.
+  """
+  def coerce_base(base_iri)
+
+  def coerce_base(module) when is_atom(module) do
+    if RDF.Vocabulary.Namespace.vocabulary_namespace?(module) do
+      apply(module, :__base_iri__, [])
+      |> new()
+    else
+      new(module)
+    end
+  end
+  def coerce_base(base_iri), do: new(base_iri)
+
+
   @doc """
   Returns the given value unchanged if it's a valid IRI, otherwise raises an exception.
 
diff --git a/lib/rdf/prefix_map.ex b/lib/rdf/prefix_map.ex
index 9ba7b14..cf49412 100644
--- a/lib/rdf/prefix_map.ex
+++ b/lib/rdf/prefix_map.ex
@@ -33,24 +33,12 @@ defmodule RDF.PrefixMap do
     map |> Map.new() |> new()
   end
 
-  defp normalize({prefix, %IRI{} = namespace}) when is_atom(prefix),
-    do: {prefix, namespace}
+  defp normalize({prefix, namespace}) when is_atom(prefix),
+    do: {prefix, IRI.coerce_base(namespace)}
 
   defp normalize({prefix, namespace}) when is_binary(prefix),
     do: normalize({String.to_atom(prefix), namespace})
 
-  defp normalize({prefix, namespace}) when is_binary(namespace),
-    do: normalize({prefix, IRI.new(namespace)})
-
-  defp normalize({prefix, namespace}) when is_atom(namespace) do
-    if RDF.Vocabulary.Namespace.vocabulary_namespace?(namespace) do
-      normalize({prefix, apply(namespace, :__base_iri__, [])})
-    else
-      raise ArgumentError,
-            "Invalid prefix mapping for #{inspect(prefix)}, #{inspect(namespace)} is not a vocabulary namespace"
-    end
-  end
-
   defp normalize({prefix, namespace}),
     do:
       raise(ArgumentError, "Invalid prefix mapping: #{inspect(prefix)} => #{inspect(namespace)}")
diff --git a/test/unit/iri_test.exs b/test/unit/iri_test.exs
index 055834d..b201b5e 100644
--- a/test/unit/iri_test.exs
+++ b/test/unit/iri_test.exs
@@ -106,6 +106,44 @@ defmodule RDF.IRITest do
   end
 
 
+  describe "coerce_base/1" do
+    test "with a string" do
+      assert IRI.coerce_base("http://example.com/") == IRI.new("http://example.com/")
+    end
+
+    test "with a RDF.IRI" do
+      assert IRI.coerce_base(IRI.new("http://example.com/")) == IRI.new("http://example.com/")
+    end
+
+    test "with a URI" do
+      assert IRI.coerce_base(URI.parse("http://example.com/")) ==
+               IRI.new(URI.parse("http://example.com/"))
+    end
+
+    test "with a resolvable atom" do
+      assert IRI.coerce_base(EX.Foo) == IRI.new(EX.Foo)
+    end
+
+    test "with a non-resolvable atom" do
+      assert_raise RDF.Namespace.UndefinedTermError, fn -> IRI.coerce_base(Foo.Bar) end
+    end
+
+    test "with Elixirs special atoms" do
+      assert_raise FunctionClauseError, fn -> IRI.coerce_base(true) end
+      assert_raise FunctionClauseError, fn -> IRI.coerce_base(false) end
+      assert_raise FunctionClauseError, fn -> IRI.coerce_base(nil) end
+    end
+
+    test "with a RDF.Vocabulary.Namespace module" do
+      assert IRI.coerce_base(EX) == IRI.new(EX.__base_iri__)
+    end
+
+    test "with a RDF.Vocabulary.Namespace module which is not loaded yet" do
+      assert IRI.coerce_base(RDF.NS.SKOS) == ~I<http://www.w3.org/2004/02/skos/core#>
+    end
+  end
+
+
   describe "valid!/1" do
     test "with valid iris" do
       Enum.each(valid_iris(), fn valid_iri ->
@@ -277,7 +315,6 @@ defmodule RDF.IRITest do
     end
   end
 
-
   describe "parse/1" do
     test "with absolute and relative iris" do
       Enum.each(absolute_iris() ++ relative_iris(), fn iri ->
diff --git a/test/unit/prefix_map_test.exs b/test/unit/prefix_map_test.exs
index c8f95fe..66f195b 100644
--- a/test/unit/prefix_map_test.exs
+++ b/test/unit/prefix_map_test.exs
@@ -80,7 +80,7 @@ defmodule RDF.PrefixMapTest do
     end
 
     test "when the IRI namespace is given as an atom" do
-      assert_raise ArgumentError, "Invalid prefix mapping for :ex, :foo is not a vocabulary namespace", fn ->
+      assert_raise RDF.Namespace.UndefinedTermError, "foo is not a term on a RDF.Namespace", fn ->
         PrefixMap.add(@example1, :ex, :foo)
       end
     end