Merge pull request #62 from core-api/internal-refactoring

tomchristie · tomchristie · commit 1fe341e3b819 · 2016-01-26T14:01:57.000Z
Internal refactoring
diff --git a/coreapi/__init__.py b/coreapi/__init__.py
@@ -6,7 +6,7 @@
 from coreapi import codecs, history, transports
 
 
-__version__ = '1.13.1'
+__version__ = '1.13.2'
 __all__ = [
     'Array', 'Document', 'Link', 'Object', 'Error', 'Field',
     'ParseError', 'NotAcceptable', 'TransportError', 'ErrorMessage',
diff --git a/coreapi/transports/http.py b/coreapi/transports/http.py
@@ -12,10 +12,100 @@
 import uritemplate
 
 
+def _get_http_method(action):
+    if not action:
+        return 'GET'
+    return action.upper()
+
+
+def _seperate_params(method, fields, params=None):
+    """
+    Seperate the params into their location types: path, query, or form.
+    """
+    if params is None:
+        return ({}, {}, {})
+
+    field_map = {field.name: field for field in fields}
+    path_params = {}
+    query_params = {}
+    form_params = {}
+    for key, value in params.items():
+        if key not in field_map or not field_map[key].location:
+            # Default is 'query' for 'GET'/'DELETE', and 'form' others.
+            location = 'query' if method in ('GET', 'DELETE') else 'form'
+        else:
+            location = field_map[key].location
+
+        if location == 'path':
+            path_params[key] = value
+        elif location == 'query':
+            query_params[key] = value
+        else:
+            form_params[key] = value
+
+    return path_params, query_params, form_params
+
+
+def _expand_path_params(url, path_params):
+    """
+    Given a templated URL and some parameters that have been provided,
+    expand the URL.
+    """
+    if path_params:
+        return uritemplate.expand(url, path_params)
+    return url
+
+
+def _get_headers(url, decoders=None, credentials=None, extra_headers=None):
+    """
+    Return a dictionary of HTTP headers to use in the outgoing request.
+    """
+    if decoders is None:
+        decoders = default_decoders
+
+    accept = ', '.join([decoder.media_type for decoder in decoders])
+
+    headers = {
+        'accept': accept
+    }
+
+    if credentials:
+        # Include any authorization credentials relevant to this domain.
+        url_components = urlparse.urlparse(url)
+        host = url_components.netloc
+        if host in credentials:
+            headers['authorization'] = credentials[host]
+
+    if extra_headers:
+        # Include any custom headers associated with this transport.
+        headers.update(extra_headers)
+
+    return headers
+
+
+def _make_http_request(url, method, headers=None, query_params=None, form_params=None):
+    """
+    Make an HTTP request and return an HTTP response.
+    """
+    opts = {
+        "headers": headers or {}
+    }
+
+    if query_params:
+        opts['params'] = query_params
+    elif form_params:
+        opts['data'] = json.dumps(form_params)
+        opts['headers']['content-type'] = 'application/json'
+
+    return requests.request(method, url, **opts)
+
+
 def _coerce_to_error_content(node):
-    # Errors should not contain nested documents or links.
-    # If we get a 4xx or 5xx response with a Document, then coerce it
-    # into plain data.
+    """
+    Errors should not contain nested documents or links.
+    If we get a 4xx or 5xx response with a Document, then coerce
+    the document content into plain data.
+    """
     if isinstance(node, (Document, Object)):
         # Strip Links from Documents, treat Documents as plain dicts.
         return OrderedDict([
@@ -33,6 +123,9 @@ def _coerce_to_error_content(node):
 
 
 def _coerce_to_error(obj, default_title):
+    """
+    Given an arbitrary return result, coerce it into an Error instance.
+    """
     if isinstance(obj, Document):
         return Error(
             title=obj.title or default_title,
@@ -42,14 +135,53 @@ def _coerce_to_error(obj, default_title):
         return Error(title=default_title, content=obj)
     elif isinstance(obj, list):
         return Error(title=default_title, content={'messages': obj})
+    elif obj is None:
+        return Error(title=default_title)
     return Error(title=default_title, content={'message': obj})
 
 
-def _get_accept_header(decoders=None):
-    if decoders is None:
-        decoders = default_decoders
+def _decode_result(response, decoders=None):
+    """
+    Given an HTTP response, return the decoded Core API document.
+    """
+    if response.content:
+        # Content returned in response. We should decode it.
+        content_type = response.headers.get('content-type')
+        codec = negotiate_decoder(content_type, decoders=decoders)
+        result = codec.load(response.content, base_url=response.url)
+    else:
+        # No content returned in response.
+        result = None
+
+    # Coerce 4xx and 5xx codes into errors.
+    is_error = response.status_code >= 400 and response.status_code <= 599
+    if is_error and not isinstance(result, Error):
+        result = _coerce_to_error(result, default_title=response.reason)
 
-    return ', '.join([decoder.media_type for decoder in decoders])
+    return result
+
+
+def _handle_inplace_replacements(document, link, link_ancestors):
+    """
+    Given a new document, and the link/ancestors it was created,
+    determine if we should:
+
+    * Make an inline replacement and then return the modified document tree.
+    * Return the new document as-is.
+    """
+    if link.inplace is None:
+        inplace = link.action.lower() in ('put', 'patch', 'delete')
+    else:
+        inplace = link.inplace
+
+    if inplace:
+        root = link_ancestors[0].document
+        keys_to_link_parent = link_ancestors[-1].keys
+        if document is None:
+            return root.delete_in(keys_to_link_parent)
+        return root.set_in(keys_to_link_parent, document)
+
+    return document
 
 
 class HTTPTransport(BaseTransport):
@@ -70,133 +202,17 @@ def headers(self):
         return self._headers
 
     def transition(self, link, params=None, decoders=None, link_ancestors=None):
-        method = self.get_http_method(link.action)
-        path_params, query_params, form_params = self.seperate_params(method, link.fields, params)
-        url = self.expand_path_params(link.url, path_params)
-        headers = self.get_headers(url, decoders)
-        response = self.make_http_request(url, method, headers, query_params, form_params)
-        document = self.load_document(response, decoders)
-
-        if isinstance(document, Document) and link_ancestors:
-            document = self.handle_inplace_replacements(document, link, link_ancestors)
-
-        if isinstance(document, Error):
-            raise ErrorMessage(document)
-
-        return document
-
-    def get_http_method(self, action):
-        if not action:
-            return 'GET'
-        return action.upper()
-
-    def seperate_params(self, method, fields, params=None):
-        """
-        Seperate the params into their location types: path, query, or form.
-        """
-        if params is None:
-            return ({}, {}, {})
-
-        field_map = {field.name: field for field in fields}
-        path_params = {}
-        query_params = {}
-        form_params = {}
-        for key, value in params.items():
-            if key not in field_map or not field_map[key].location:
-                # Default is 'query' for 'GET'/'DELETE', and 'form' others.
-                location = 'query' if method in ('GET', 'DELETE') else 'form'
-            else:
-                location = field_map[key].location
-
-            if location == 'path':
-                path_params[key] = value
-            elif location == 'query':
-                query_params[key] = value
-            else:
-                form_params[key] = value
-
-        return path_params, query_params, form_params
-
-    def expand_path_params(self, url, path_params):
-        if path_params:
-            return uritemplate.expand(url, path_params)
-        return url
-
-    def get_headers(self, url, decoders=None):
-        """
-        Return a dictionary of HTTP headers to use in the outgoing request.
-        """
-        headers = {
-            'accept': _get_accept_header(decoders)
-        }
-
-        if self.credentials:
-            # Include any authorization credentials relevant to this domain.
-            url_components = urlparse.urlparse(url)
-            host = url_components.netloc
-            if host in self.credentials:
-                headers['authorization'] = self.credentials[host]
-
-        if self.headers:
-            # Include any custom headers associated with this transport.
-            headers.update(self.headers)
-
-        return headers
-
-    def make_http_request(self, url, method, headers=None, query_params=None, form_params=None):
-        """
-        Make an HTTP request and return an HTTP response.
-        """
-        opts = {
-            "headers": headers or {}
-        }
-
-        if query_params:
-            opts['params'] = query_params
-        elif form_params:
-            opts['data'] = json.dumps(form_params)
-            opts['headers']['content-type'] = 'application/json'
-
-        return requests.request(method, url, **opts)
-
-    def load_document(self, response, decoders=None):
-        """
-        Given an HTTP response, return the decoded Core API document.
-        """
-        if response.content:
-            # Content returned in response. We should decode it.
-            content_type = response.headers.get('content-type')
-            codec = negotiate_decoder(content_type, decoders=decoders)
-            document = codec.load(response.content, base_url=response.url)
-        else:
-            # No content returned in response.
-            document = None
-
-        # Coerce 4xx and 5xx codes into errors.
-        is_error = response.status_code >= 400 and response.status_code <= 599
-        if is_error and not isinstance(document, Error):
-            document = _coerce_to_error(document, default_title=response.reason)
-
-        return document
-
-    def handle_inplace_replacements(self, document, link, link_ancestors):
-        """
-        Given a new document, and the link/ancestors it was created,
-        determine if we should:
-
-        * Make an inline replacement and then return the modified document tree.
-        * Return the new document as-is.
-        """
-        if link.inplace is None:
-            inplace = link.action.lower() in ('put', 'patch', 'delete')
-        else:
-            inplace = link.inplace
+        method = _get_http_method(link.action)
+        path_params, query_params, form_params = _seperate_params(method, link.fields, params)
+        url = _expand_path_params(link.url, path_params)
+        headers = _get_headers(url, decoders, self.credentials, self.headers)
+        response = _make_http_request(url, method, headers, query_params, form_params)
+        result = _decode_result(response, decoders)
+
+        if isinstance(result, Document) and link_ancestors:
+            result = _handle_inplace_replacements(result, link, link_ancestors)
 
-        if inplace:
-            root = link_ancestors[0].document
-            keys_to_link_parent = link_ancestors[-1].keys
-            if document is None:
-                return root.delete_in(keys_to_link_parent)
-            return root.set_in(keys_to_link_parent, document)
+        if isinstance(result, Error):
+            raise ErrorMessage(result)
 
-        return document
+        return result
diff --git a/tests/test_transitions.py b/tests/test_transitions.py
@@ -1,6 +1,7 @@
 # coding: utf-8
 from coreapi import Document, Link, Client
 from coreapi.transports import HTTPTransport
+from coreapi.transports.http import _handle_inplace_replacements
 import pytest
 
 
@@ -17,7 +18,7 @@ def transition(self, link, params=None, decoders=None, link_ancestors=None):
         else:
             document = None
 
-        return self.handle_inplace_replacements(document, link, link_ancestors)
+        return _handle_inplace_replacements(document, link, link_ancestors)
 
 
 client = Client(transports=[MockTransport()])
diff --git a/tests/test_transport.py b/tests/test_transport.py
@@ -102,31 +102,3 @@ def mockreturn(method, url, **opts):
     link = Link(url='http://example.org', action='delete')
     doc = http.transition(link)
     assert doc is None
-
-
-# Test credentials
-
-def test_credentials(monkeypatch):
-    credentials = {'example.org': 'Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ=='}
-    transport = HTTPTransport(credentials=credentials)
-
-    # Requests to example.org include credentials.
-    headers = transport.get_headers('http://example.org/123')
-    assert 'authorization' in headers
-    assert headers['authorization'] == 'Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ=='
-
-    # Requests to other.org do not include credentials.
-    headers = transport.get_headers('http://other.org/123')
-    assert 'authorization' not in headers
-
-
-# Test custom headers
-
-def test_headers(monkeypatch):
-    headers = {'User-Agent': 'Example v1.0'}
-    transport = HTTPTransport(headers=headers)
-
-    # Requests include custom headers.
-    headers = transport.get_headers('http://example.org/123')
-    assert 'user-agent' in headers
-    assert headers['user-agent'] == 'Example v1.0'
