From a73aa6b5ecb125932d4af4f95b5a54bb38168b47 Mon Sep 17 00:00:00 2001
From: Carlton Gibson <carlton.gibson@noumenal.es>
Date: Thu, 5 Oct 2017 09:25:48 +0200
Subject: [PATCH] Adjust insert_into to raise ValueError

---
 rest_framework/schemas/generators.py | 23 ++++++++++++++++++++++-
 tests/test_schemas.py                | 12 +++++++++---
 2 files changed, 31 insertions(+), 4 deletions(-)

diff --git a/rest_framework/schemas/generators.py b/rest_framework/schemas/generators.py
index 3e927527c..a9fa15b87 100644
--- a/rest_framework/schemas/generators.py
+++ b/rest_framework/schemas/generators.py
@@ -51,6 +51,19 @@ def is_api_view(callback):
     return (cls is not None) and issubclass(cls, APIView)
 
 
+INSERT_INTO_COLLISION_FMT = """
+Schema Naming Collision.
+
+coreapi.Link for URL path {value_url} cannot be inserted into schema.
+Position conflicts with coreapi.Link for URL path {target_url}.
+
+Attemped to insert link with keys: {keys}.
+
+Adjust URLs to avoid naming collision or override `SchemaGenerator.get_keys()`
+to customise schema structure.
+"""
+
+
 def insert_into(target, keys, value):
     """
     Nested dictionary insertion.
@@ -64,7 +77,15 @@ def insert_into(target, keys, value):
         if key not in target:
             target[key] = {}
         target = target[key]
-    target[keys[-1]] = value
+    try:
+        target[keys[-1]] = value
+    except TypeError:
+        msg = INSERT_INTO_COLLISION_FMT.format(
+            value_url=value.url,
+            target_url=target.url,
+            keys=keys
+        )
+        raise ValueError(msg)
 
 
 def is_custom_action(action):
diff --git a/tests/test_schemas.py b/tests/test_schemas.py
index 0c2589394..6555a13b8 100644
--- a/tests/test_schemas.py
+++ b/tests/test_schemas.py
@@ -778,7 +778,9 @@ class TestURLNamingCollisions(TestCase):
         ]
 
         generator = SchemaGenerator(title='Naming Colisions', patterns=patterns)
-        schema = generator.get_schema()
+
+        with pytest.raises(ValueError):
+            generator.get_schema()
 
     def test_manually_routing_generic_view(self):
         patterns = [
@@ -793,7 +795,9 @@ class TestURLNamingCollisions(TestCase):
         ]
 
         generator = SchemaGenerator(title='Naming Colisions', patterns=patterns)
-        schema = generator.get_schema()
+
+        with pytest.raises(ValueError):
+            generator.get_schema()
 
     def test_from_router(self):
         patterns = [
@@ -801,4 +805,6 @@ class TestURLNamingCollisions(TestCase):
         ]
 
         generator = SchemaGenerator(title='Naming Colisions', patterns=patterns)
-        schema = generator.get_schema()
+
+        with pytest.raises(ValueError):
+            generator.get_schema()