Use warnings.warn rather than log warning in app log

docs/etag.rst

@@ -201,9 +201,8 @@ It is up to the developer to call
 :meth:`Blueprint.check_etag <Blueprint.check_etag>` in the view function. It
 can't be automatic.
 
-If ETag is enabled and :meth:`check_etag <Blueprint.check_etag>` is not called,
-a warning is logged at runtime. When in `DEBUG` or `TESTING` mode, an exception
-is raised.
+A warning is issued if ETag is enabled and
+:meth:`check_etag <Blueprint.check_etag>` is not called.
 
 Include Headers Content in ETag
 -------------------------------

flask_smorest/etag.py

@@ -3,14 +3,14 @@
 from functools import wraps
 from copy import deepcopy
 import http
+import warnings
 
 import hashlib
 
 from marshmallow import Schema
 from flask import request, current_app, json
 
 from .exceptions import (
-    CheckEtagNotCalledError,
     PreconditionRequired, PreconditionFailed, NotModified)
 from .utils import deepupdate, get_appcontext
 
@@ -150,15 +150,16 @@ def check_etag(self, etag_data, etag_schema=None):
         Must be called from resource code to check ETag.
 
         Unfortunately, there is no way to call it automatically. It is the
-        developer's responsability to do it. However, a warning is logged at
+        developer's responsability to do it. However, a warning is issued at
         runtime if this function was not called.
 
-        Logs a warning if called in a method other than one of
-        PUT, PATCH, DELETE.
+        Issues a warning if called in a method other than PUT, PATCH, or
+        DELETE.
         """
         if request.method not in self.METHODS_NEEDING_CHECK_ETAG:
-            current_app.logger.warning(
-                'ETag cannot be checked on {} request.'.format(request.method))
+            warnings.warn(
+                'ETag cannot be checked on {} request.'.format(request.method)
+            )
         if _is_etag_enabled():
             etag_schema = etag_schema or _get_etag_ctx().get('etag_schema')
             new_etag = self._generate_etag(etag_data, etag_schema)
@@ -169,23 +170,18 @@ def check_etag(self, etag_data, etag_schema=None):
     def _verify_check_etag(self):
         """Verify check_etag was called in resource code
 
-        Log a warning if ETag is enabled but check_etag was not called in
+        Issues a warning if ETag is enabled but check_etag was not called in
         resource code in a PUT, PATCH or DELETE method.
 
-        Raise CheckEtagNotCalledError when in debug or testing mode.
-
         This is called automatically. It is meant to warn the developer about
         an issue in his ETag management.
         """
         if request.method in self.METHODS_NEEDING_CHECK_ETAG:
             if not _get_etag_ctx().get('etag_checked'):
-                message = (
+                warnings.warn(
                     'ETag not checked in endpoint {} on {} request.'
-                    .format(request.endpoint, request.method))
-                app = current_app
-                app.logger.warning(message)
-                if app.debug or app.testing:
-                    raise CheckEtagNotCalledError(message)
+                    .format(request.endpoint, request.method)
+                )
 
     def _check_not_modified(self, etag):
         """Raise NotModified if etag is in If-None-Match header
@@ -207,12 +203,13 @@ def set_etag(self, etag_data, etag_schema=None):
         decorated with the ``response`` decorator, in which case the ETag is
         computed by default from response data if ``set_etag`` is not called.
 
-        Logs a warning if called in a method other than one of
-        GET, HEAD, POST, PUT, PATCH.
+        Issues a warning if called in a method other than GET, HEAD, POST, PUT
+        or PATCH.
         """
         if request.method not in self.METHODS_ALLOWING_SET_ETAG:
-            current_app.logger.warning(
-                'ETag cannot be set on {} request.'.format(request.method))
+            warnings.warn(
+                'ETag cannot be set on {} request.'.format(request.method)
+            )
         if _is_etag_enabled():
             etag_schema = etag_schema or _get_etag_ctx().get('etag_schema')
             new_etag = self._generate_etag(etag_data, etag_schema)

flask_smorest/exceptions.py

@@ -11,10 +11,6 @@ class MissingAPIParameterError(FlaskSmorestError):
     """Missing API parameter"""
 
 
-class CheckEtagNotCalledError(FlaskSmorestError):
-    """ETag enabled on resource but check_etag not called"""
-
-
 class NotModified(wexc.HTTPException, FlaskSmorestError):
     """Resource was not modified (Etag is unchanged)
 

flask_smorest/pagination.py

@@ -8,14 +8,14 @@
 - Post-pagination: the resource returns an iterator (typically a DB cursor) and
   a pager is provided to paginate the data and get the total number of items.
 """
-
 from copy import deepcopy
 from collections import OrderedDict
 from functools import wraps
 import http
 import json
+import warnings
 
-from flask import request, current_app
+from flask import request
 
 import marshmallow as ma
 from webargs.flaskparser import FlaskParser
@@ -199,8 +199,8 @@ def wrapper(*args, **kwargs):
                 # Set pagination metadata in response
                 if self.PAGINATION_HEADER_FIELD_NAME is not None:
                     if page_params.item_count is None:
-                        current_app.logger.warning(
-                            'item_count not set in endpoint {}'
+                        warnings.warn(
+                            'item_count not set in endpoint {}.'
                             .format(request.endpoint)
                         )
                     else:

tests/test_etag.py

@@ -3,24 +3,23 @@
 from collections import OrderedDict
 import json
 import hashlib
-from unittest import mock
 
 import pytest
 
-from flask import jsonify, Response
+from flask import jsonify, Response, request as f_request
 from flask.views import MethodView
 
 from flask_smorest import Api, Blueprint, abort
 from flask_smorest.etag import _get_etag_ctx
 from flask_smorest.exceptions import (
-    CheckEtagNotCalledError,
     NotModified, PreconditionRequired, PreconditionFailed)
 from flask_smorest.utils import get_appcontext
 
 from .mocks import ItemNotFound
 
 
 HTTP_METHODS = ['OPTIONS', 'HEAD', 'GET', 'POST', 'PUT', 'PATCH', 'DELETE']
+HTTP_METHODS_ALLOWING_SET_ETAG = ['GET', 'HEAD', 'POST', 'PUT', 'PATCH']
 
 
 @pytest.fixture(params=[True, False])
@@ -251,7 +250,7 @@ def test_etag_check_etag_wrong_method_warning(
         app.config['ETAG_DISABLED'] = etag_disabled
         blp = Blueprint('test', __name__)
 
-        with mock.patch.object(app.logger, 'warning') as mock_warning:
+        with pytest.warns(None) as record:
             with app.test_request_context(
                     '/',
                     method=method,
@@ -263,52 +262,43 @@ def test_etag_check_etag_wrong_method_warning(
                 except PreconditionFailed:
                     pass
                 if method in ['PUT', 'PATCH', 'DELETE']:
-                    assert not mock_warning.called
+                    assert not record
                 else:
-                    assert mock_warning.called
+                    assert len(record) == 1
+                    assert record[0].category == UserWarning
+                    assert str(record[0].message) == (
+                        'ETag cannot be checked on {} request.'
+                        .format(method)
+                    )
 
     @pytest.mark.parametrize('method', HTTP_METHODS)
     def test_etag_verify_check_etag_warning(self, app, method):
         blp = Blueprint('test', __name__)
         old_item = {'item_id': 1, 'db_field': 0}
         old_etag = blp._generate_etag(old_item)
 
-        with mock.patch.object(app.logger, 'warning') as mock_warning:
+        with pytest.warns(None) as record:
             with app.test_request_context(
                     '/',
                     method=method,
                     headers={'If-Match': old_etag},
             ):
                 blp._verify_check_etag()
                 if method in ['PUT', 'PATCH', 'DELETE']:
-                    assert mock_warning.called
+                    assert len(record) == 1
+                    assert record[0].category == UserWarning
+                    assert str(record[0].message) == (
+                        'ETag not checked in endpoint {} on {} request.'
+                        .format(f_request.endpoint, method)
+                    )
                 else:
-                    assert not mock_warning.called
+                    assert not record
                 blp.check_etag(old_item)
-                mock_warning.reset_mock()
+                record.clear()
                 blp._verify_check_etag()
-                assert not mock_warning.called
+                assert not record
 
-    @pytest.mark.parametrize('method', HTTP_METHODS)
-    @pytest.mark.parametrize('debug', (True, False))
-    @pytest.mark.parametrize('testing', (True, False))
-    def test_etag_verify_check_etag_exception(
-            self, app, method, debug, testing):
-        app.config['DEBUG'] = debug
-        app.config['TESTING'] = testing
-        blp = Blueprint('test', __name__)
-
-        with app.test_request_context('/', method=method):
-            if (debug or testing) and method in ['PUT', 'PATCH', 'DELETE']:
-                with pytest.raises(
-                        CheckEtagNotCalledError,
-                        match='ETag not checked in endpoint'
-                ):
-                    blp._verify_check_etag()
-            else:
-                blp._verify_check_etag()
-
-    @pytest.mark.parametrize('method', HTTP_METHODS)
+    @pytest.mark.parametrize('method', HTTP_METHODS_ALLOWING_SET_ETAG)
     @pytest.mark.parametrize('etag_disabled', (True, False))
     def test_etag_set_etag(self, app, schemas, method, etag_disabled):
         app.config['ETAG_DISABLED'] = etag_disabled
@@ -369,18 +359,23 @@ def test_etag_set_etag(self, app, schemas, method, etag_disabled):
 
     @pytest.mark.parametrize('etag_disabled', (True, False))
     @pytest.mark.parametrize('method', HTTP_METHODS)
-    def test_set_etag_method_not_allowed_warning(
+    def test_etag_set_etag_method_not_allowed_warning(
             self, app, method, etag_disabled):
         app.config['ETAG_DISABLED'] = etag_disabled
         blp = Blueprint('test', __name__)
 
-        with mock.patch.object(app.logger, 'warning') as mock_warning:
+        with pytest.warns(None) as record:
             with app.test_request_context('/', method=method):
                 blp.set_etag(None)
-            if method in ['GET', 'HEAD', 'POST', 'PUT', 'PATCH']:
-                assert not mock_warning.called
+            if method in HTTP_METHODS_ALLOWING_SET_ETAG:
+                assert not record
             else:
-                assert mock_warning.called
+                assert len(record) == 1
+                assert record[0].category == UserWarning
+                assert str(record[0].message) == (
+                    'ETag cannot be set on {} request.'
+                    .format(method)
+                )
 
     @pytest.mark.parametrize('paginate', (True, False))
     def test_etag_set_etag_in_response(self, app, schemas, paginate):

tests/test_pagination.py

@@ -3,7 +3,6 @@
 from itertools import product
 from collections import namedtuple
 import json
-from unittest import mock
 
 import pytest
 
@@ -196,16 +195,18 @@ def func(pagination_parameters):
         api.register_blueprint(blp)
         client = app.test_client()
 
-        with mock.patch.object(app.logger, 'warning') as mock_warning:
+        with pytest.warns(None) as record:
             response = client.get('/test/')
-            assert response.status_code == 200
-            assert 'X-Pagination' not in response.headers
-            if header_name is None:
-                assert mock_warning.call_count == 0
-            else:
-                assert mock_warning.call_count == 1
-                assert mock_warning.call_args == (
-                    ('item_count not set in endpoint test.func',), )
+        if header_name is None:
+            assert not record
+        else:
+            assert len(record) == 1
+            assert record[0].category == UserWarning
+            assert str(record[0].message) == (
+                'item_count not set in endpoint test.func.'
+            )
+        assert response.status_code == 200
+        assert 'X-Pagination' not in response.headers
 
     @pytest.mark.parametrize('collection', [1000, ], indirect=True)
     def test_pagination_parameters(self, app_fixture):