feat: Add support for open api servers

In openapi 3 the 'schemes' and 'basePath' were replaced with a single
property called 'servers', in this property we introduce the available
servers with the full path, for example:

```yaml
servers:
  - url: https://statsapi.web.nhl.com/api/v1
 ```

With this change, a flag is added in the parsing of the context
`is_open_api` that can be used to check for the new properties available
in open api 3.

fixes httpie#197

Signed-off-by: Arturo Volpe <[email protected]>

http_prompt/context/__init__.py

@@ -1,4 +1,5 @@
 from http_prompt.tree import Node
+from urllib.parse import urlparse
 
 
 class Context(object):
@@ -15,19 +16,28 @@ def __init__(self, url=None, spec=None):
         # Create a tree for supporting API spec and ls command
         self.root = Node('root')
         if spec:
+            is_open_api = 'openapi' in spec
+
             if not self.url:
-                self.url = spec.get('servers')[0].get('url')
-                if 'servers' in spec:
-                    self.url = spec.get('servers')[0].get('url')
+                if is_open_api:
+                    # In open api, the schemes are in the 'server' element,
+                    self.url = spec.get('servers', [{'url': 'http://localhost:8000'}])[0].get('url')
                 else:
                     schemes = spec.get('schemes')
                     scheme = schemes[0] if schemes else 'https'
                     self.url = (scheme + '://' +
                                 spec.get('host', 'http://localhost:8000') +
                                 spec.get('basePath', ''))
 
-            base_path_tokens = list(filter(lambda s: s,
-                                    spec.get('basePath', '').split('/')))
+            # in open api, there is no 'basePath', we should extract that from the url
+            if is_open_api:
+                server = spec.get('servers', [{'url': 'http://localhost:8000'}])[0].get('url')
+                base_path_tokens = list(filter(lambda s: s,
+                                        urlparse(server).path.split('/')))
+            else:
+                base_path_tokens = list(filter(lambda s: s,
+                                        spec.get('basePath', '').split('/')))
+
             paths = spec.get('paths')
             if paths:
                 for path in paths:

tests/test_cli.py

@@ -181,6 +181,28 @@ def test_spec_from_local_yml(self):
         self.assertEqual(set([n.name for n in context.root.children]),
                          set(['users', 'orgs']))
 
+    def test_spec_from_local_yml_openapi(self):
+        spec_filepath = self.make_tempfile("""
+            openapi: "3.0.0"
+            servers:
+              - url: https://localhost:8080/
+            paths:
+              /api/users:
+                get:
+                  description:
+              /api/orgs:
+                get:
+                  description:
+        """)
+        result, context = run_and_exit(['example.com/api', "--spec",
+                                        spec_filepath])
+        self.assertEqual(result.exit_code, 0)
+        self.assertEqual(context.url, 'http://example.com/api')
+        self.assertEqual(set([n.name for n in context.root.children]),
+                         set(['api']))
+        self.assertEqual(set([n.name for n in context.root.ls('api')]),
+                         set(['users', 'orgs']))
+
     def test_spec_basePath(self):
         spec_filepath = self.make_tempfile(json.dumps({
             'basePath': '/api/v1',