add test for the new error case

Author: pchampin

tests/expand-manifest.html

@@ -5360,6 +5360,27 @@ <h2>
 </dd>
 </dl>
 </dd>
+<dt id='te052'>
+Test te052 Definition for the empty term
+</dt>
+<dd>
+<dl class='entry'>
+<dt>id</dt>
+<dd>#te052</dd>
+<dt>Type</dt>
+<dd>jld:NegativeEvaluationTest, jld:ExpandTest</dd>
+<dt>Purpose</dt>
+<dd>Verifies that an exception is raised on expansion when a context contains a definition for the empty term</dd>
+<dt>input</dt>
+<dd>
+<a href='expand/e052-in.jsonld'>expand/e052-in.jsonld</a>
+</dd>
+<dt>expect</dt>
+<dd>
+invalid term definition
+</dd>
+</dl>
+</dd>
 <dt id='tec01'>
 Test tec01 Invalid keyword in term definition
 </dt>

tests/expand-manifest.jsonld

@@ -1624,6 +1624,13 @@
       "purpose": "Verifies that an exception is raised in Expansion when an invalid value object value is found using a value alias",
       "input": "expand/e051-in.jsonld",
       "expectErrorCode": "invalid value object value"
+    }, {
+      "@id": "#te052",
+      "@type": [ "jld:NegativeEvaluationTest", "jld:ExpandTest" ],
+      "name": "Definition for the empty term",
+      "purpose": "Verifies that an exception is raised on expansion when a context contains a definition for the empty term",
+      "input": "expand/e052-in.jsonld",
+      "expectErrorCode": "invalid term definition"
     }, {
       "@id": "#tec01",
       "@type": [ "jld:NegativeEvaluationTest", "jld:ExpandTest" ],

tests/expand/e052-in.jsonld

@@ -0,0 +1,7 @@
+{
+  "@context": {
+    "term": {"@id": "http://example.org/term"},
+    "": {"@id": "http://example.org/empty"}
+  },
+  "@id": "http://example/test#example"
+}