From 5c9ed717fc079e70c8ac48a682e4f661dff5bcf6 Mon Sep 17 00:00:00 2001
From: Alan Crosswell <alan@columbia.edu>
Date: Sun, 2 Jun 2019 10:56:50 -0400
Subject: [PATCH] fix // path prefix

---
 rest_framework/schemas/generators.py |  2 +-
 rest_framework/schemas/openapi.py    |  4 +++-
 tests/schemas/test_openapi.py        | 14 ++++++++++++++
 3 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/rest_framework/schemas/generators.py b/rest_framework/schemas/generators.py
index ecb07f935..392d385d8 100644
--- a/rest_framework/schemas/generators.py
+++ b/rest_framework/schemas/generators.py
@@ -249,7 +249,7 @@ class BaseSchemaGenerator(object):
         /api/v1/users/
         /api/v1/users/{pk}/
 
-        The path prefix is '/api/v1/'
+        The path prefix is '/api/v1'
         """
         prefixes = []
         for path in paths:
diff --git a/rest_framework/schemas/openapi.py b/rest_framework/schemas/openapi.py
index 44b281be8..c03205c3e 100644
--- a/rest_framework/schemas/openapi.py
+++ b/rest_framework/schemas/openapi.py
@@ -35,12 +35,14 @@ class SchemaGenerator(BaseSchemaGenerator):
         if not paths:
             return None
         prefix = self.determine_path_prefix(paths)
+        if prefix == '/':  # no prefix
+            prefix = ''
 
         for path, method, view in view_endpoints:
             if not self.has_view_permissions(path, method, view):
                 continue
             operation = view.schema.get_operation(path, method)
-            subpath = '/' + path[len(prefix):]
+            subpath = path[len(prefix):]
             result.setdefault(subpath, {})
             result[subpath][method.lower()] = operation
 
diff --git a/tests/schemas/test_openapi.py b/tests/schemas/test_openapi.py
index 2ddf54f01..4914c1422 100644
--- a/tests/schemas/test_openapi.py
+++ b/tests/schemas/test_openapi.py
@@ -214,6 +214,20 @@ class TestGenerator(TestCase):
         assert 'get' in example_operations
         assert 'post' in example_operations
 
+    def test_prefixed_paths_construction(self):
+        """Construction of the `paths` key with a common prefix."""
+        patterns = [
+            url(r'^api/v1/example/?$', views.ExampleListView.as_view()),
+            url(r'^api/v1/example/{pk}/?$', views.ExampleDetailView.as_view()),
+        ]
+        generator = SchemaGenerator(patterns=patterns)
+        generator._initialise_endpoints()
+
+        paths = generator.get_paths()
+
+        assert '/example/' in paths
+        assert '/example/{id}/' in paths
+
     def test_schema_construction(self):
         """Construction of the top level dictionary."""
         patterns = [