Improve test coverage for random_clustered and update function names (#…

…7273)

* Improve test_cov for random_clustered

* Add match

Co-authored-by: Ross Barnowski <rossbar@berkeley.edu>

* Cleanup invalid joint deg seq tests.

---------

Co-authored-by: Ross Barnowski <rossbar@berkeley.edu>

networkx/generators/tests/test_random_clustered.py

@@ -1,34 +1,33 @@
 import pytest
 
-import networkx
+import networkx as nx
 
 
 class TestRandomClusteredGraph:
-    def test_valid(self):
+    def test_custom_joint_degree_sequence(self):
         node = [1, 1, 1, 2, 1, 2, 0, 0]
         tri = [0, 0, 0, 0, 0, 1, 1, 1]
         joint_degree_sequence = zip(node, tri)
-        G = networkx.random_clustered_graph(joint_degree_sequence)
+        G = nx.random_clustered_graph(joint_degree_sequence)
         assert G.number_of_nodes() == 8
         assert G.number_of_edges() == 7
 
-    def test_valid2(self):
-        G = networkx.random_clustered_graph(
-            [(1, 2), (2, 1), (1, 1), (1, 1), (1, 1), (2, 0)]
-        )
+    def test_tuple_joint_degree_sequence(self):
+        G = nx.random_clustered_graph([(1, 2), (2, 1), (1, 1), (1, 1), (1, 1), (2, 0)])
         assert G.number_of_nodes() == 6
         assert G.number_of_edges() == 10
 
-    def test_invalid1(self):
-        pytest.raises(
-            (TypeError, networkx.NetworkXError),
-            networkx.random_clustered_graph,
-            [[1, 1], [2, 1], [0, 1]],
-        )
+    def test_invalid_joint_degree_sequence_type(self):
+        with pytest.raises(nx.NetworkXError, match="Invalid degree sequence"):
+            nx.random_clustered_graph([[1, 1], [2, 1], [0, 1]])
 
-    def test_invalid2(self):
-        pytest.raises(
-            (TypeError, networkx.NetworkXError),
-            networkx.random_clustered_graph,
-            [[1, 1], [1, 2], [0, 1]],
-        )
+    def test_invalid_joint_degree_sequence_value(self):
+        with pytest.raises(nx.NetworkXError, match="Invalid degree sequence"):
+            nx.random_clustered_graph([[1, 1], [1, 2], [0, 1]])
+
+    def test_directed_graph_raises_error(self):
+        with pytest.raises(nx.NetworkXError, match="Directed Graph not supported"):
+            nx.random_clustered_graph(
+                [(1, 2), (2, 1), (1, 1), (1, 1), (1, 1), (2, 0)],
+                create_using=nx.DiGraph,
+            )