api: add get_method API call.

- in addition use it's mechanics to propose users other methods if the
calling method is not found.

rhodecode/api/__init__.py

@@ -22,6 +22,7 @@ import inspect
 import itertools
 import logging
 import types
+import fnmatch
 
 import decorator
 import venusian
@@ -47,6 +48,18 @@ DEFAULT_RENDERER = 'jsonrpc_renderer'
 DEFAULT_URL = '/_admin/apiv2'
 
 
+def find_methods(jsonrpc_methods, pattern):
+    matches = OrderedDict()
+    if not isinstance(pattern, (list, tuple)):
+        pattern = [pattern]
+
+    for single_pattern in pattern:
+        for method_name, method in jsonrpc_methods.items():
+            if fnmatch.fnmatch(method_name, single_pattern):
+                matches[method_name] = method
+    return matches
+
+
 class ExtJsonRenderer(object):
     """
     Custom renderer that mkaes use of our ext_json lib
@@ -143,7 +156,19 @@ def exception_view(exc, request):
         log.debug('json-rpc method `%s` not found in list of '
                   'api calls: %s, rpc_id:%s',
                   method, request.registry.jsonrpc_methods.keys(), rpc_id)
-        fault_message = "No such method: {}".format(method)
+
+        similar = 'none'
+        try:
+            similar_paterns = ['*{}*'.format(x) for x in method.split('_')]
+            similar_found = find_methods(
+                request.registry.jsonrpc_methods, similar_paterns)
+            similar = ', '.join(similar_found.keys()) or similar
+        except Exception:
+            # make the whole above block safe
+            pass
+
+        fault_message = "No such method: {}. Similar methods: {}".format(
+            method, similar)
 
     return jsonrpc_error(request, fault_message, rpc_id)
 
@@ -348,9 +373,10 @@ class RoutePredicate(object):
 class NotFoundPredicate(object):
     def __init__(self, val, config):
         self.val = val
+        self.methods = config.registry.jsonrpc_methods
 
     def text(self):
-        return 'jsonrpc method not found = %s' % self.val
+        return 'jsonrpc method not found = {}.'.format(self.val)
 
     phash = text
 

rhodecode/api/tests/test_api.py

@@ -80,7 +80,13 @@ class TestApi(object):
     def test_api_non_existing_method(self, request):
         id_, params = build_data(self.apikey, 'not_existing', args='xx')
         response = api_call(self.app, params)
-        expected = 'No such method: not_existing'
+        expected = 'No such method: not_existing. Similar methods: none'
+        assert_error(id_, expected, given=response.body)
+
+    def test_api_non_existing_method_have_similar(self, request):
+        id_, params = build_data(self.apikey, 'comment', args='xx')
+        response = api_call(self.app, params)
+        expected = 'No such method: comment. Similar methods: changeset_comment, comment_pull_request, comment_commit'
         assert_error(id_, expected, given=response.body)
 
     def test_api_disabled_user(self, request):

rhodecode/api/tests/test_get_method.py

@@ -0,0 +1,58 @@
+# -*- coding: utf-8 -*-
+
+# Copyright (C) 2010-2017 RhodeCode GmbH
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License, version 3
+# (only), as published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+# This program is dual-licensed. If you wish to learn more about the
+# RhodeCode Enterprise Edition, including its added features, Support services,
+# and proprietary license terms, please see https://rhodecode.com/licenses/
+
+
+import pytest
+
+from rhodecode.api.tests.utils import build_data, api_call, assert_ok
+
+
+@pytest.mark.usefixtures("testuser_api", "app")
+class TestGetMethod(object):
+    def test_get_methods_no_matches(self):
+        id_, params = build_data(self.apikey, 'get_method', pattern='hello')
+        response = api_call(self.app, params)
+
+        expected = []
+        assert_ok(id_, expected, given=response.body)
+
+    def test_get_methods(self):
+        id_, params = build_data(self.apikey, 'get_method', pattern='*comment*')
+        response = api_call(self.app, params)
+
+        expected = ['changeset_comment', 'comment_pull_request',
+                    'comment_commit']
+        assert_ok(id_, expected, given=response.body)
+
+    def test_get_methods_on_single_match(self):
+        id_, params = build_data(self.apikey, 'get_method', pattern='*comment_commit*')
+        response = api_call(self.app, params)
+
+        expected = ['comment_commit',
+                    {'apiuser': '<RequiredType>',
+                     'comment_type': "<Optional:u'note'>",
+                     'commit_id': '<RequiredType>',
+                     'message': '<RequiredType>',
+                     'repoid': '<RequiredType>',
+                     'request': '<RequiredType>',
+                     'resolves_comment_id': '<Optional:None>',
+                     'status': '<Optional:None>',
+                     'userid': '<Optional:<OptionalAttr:apiuser>>'}]
+        assert_ok(id_, expected, given=response.body)

rhodecode/api/views/server_api.py

@@ -18,10 +18,12 @@
 # RhodeCode Enterprise Edition, including its added features, Support services,
 # and proprietary license terms, please see https://rhodecode.com/licenses/
 
-
+import inspect
 import logging
+import itertools
 
-from rhodecode.api import jsonrpc_method, JSONRPCError, JSONRPCForbidden
+from rhodecode.api import (
+    jsonrpc_method, JSONRPCError, JSONRPCForbidden, find_methods)
 
 from rhodecode.api.utils import (
     Optional, OAttr, has_superadmin_permission, get_user_or_error)
@@ -243,3 +245,77 @@ def cleanup_sessions(request, apiuser, older_then=Optional(60)):
         raise JSONRPCError(
             'Error occurred during session cleanup'
         )
+
+
+@jsonrpc_method()
+def get_method(request, apiuser, pattern=Optional('*')):
+    """
+    Returns list of all available API methods. By default match pattern
+    os "*" but any other pattern can be specified. eg *comment* will return
+    all methods with comment inside them. If just single method is matched
+    returned data will also include method specification
+
+    This command can only be run using an |authtoken| with admin rights to
+    the specified repository.
+
+    This command takes the following options:
+
+    :param apiuser: This is filled automatically from the |authtoken|.
+    :type apiuser: AuthUser
+    :param pattern: pattern to match method names against
+    :type older_then: Optional("*")
+
+    Example output:
+
+    .. code-block:: bash
+
+      id : <id_given_in_input>
+      "result": [
+        "changeset_comment",
+        "comment_pull_request",
+        "comment_commit"
+      ]
+      error :  null
+
+    .. code-block:: bash
+
+      id : <id_given_in_input>
+      "result": [
+        "comment_commit",
+        {
+          "apiuser": "<RequiredType>",
+          "comment_type": "<Optional:u'note'>",
+          "commit_id": "<RequiredType>",
+          "message": "<RequiredType>",
+          "repoid": "<RequiredType>",
+          "request": "<RequiredType>",
+          "resolves_comment_id": "<Optional:None>",
+          "status": "<Optional:None>",
+          "userid": "<Optional:<OptionalAttr:apiuser>>"
+        }
+      ]
+      error :  null
+    """
+    if not has_superadmin_permission(apiuser):
+        raise JSONRPCForbidden()
+
+    pattern = Optional.extract(pattern)
+
+    matches = find_methods(request.registry.jsonrpc_methods, pattern)
+
+    args_desc = []
+    if len(matches) == 1:
+        func = matches[matches.keys()[0]]
+
+        argspec = inspect.getargspec(func)
+        arglist = argspec[0]
+        defaults = map(repr, argspec[3] or [])
+
+        default_empty = '<RequiredType>'
+
+        # kw arguments required by this method
+        func_kwargs = dict(itertools.izip_longest(
+            reversed(arglist), reversed(defaults), fillvalue=default_empty))
+        args_desc.append(func_kwargs)
+
+    return matches.keys() + args_desc