Merge pull request #246 from cool-RR/2020-06-20-raise-from

Fix exception causes all over the codebase

jupyter_server/kernelspecs/handlers.py

@@ -14,8 +14,9 @@ def get(self, kernel_name, path, include_body=True):
         ksm = self.kernel_spec_manager
         try:
             self.root = ksm.get_kernel_spec(kernel_name).resource_dir
-        except KeyError:
-            raise web.HTTPError(404, u'Kernel spec %s not found' % kernel_name)
+        except KeyError as e:
+            raise web.HTTPError(404, u'Kernel spec %s not found' %
+                                kernel_name) from e
         self.log.debug("Serving kernel resource from: %s", self.root)
         return web.StaticFileHandler.get(self, path, include_body=include_body)
 

jupyter_server/nbconvert/handlers.py

@@ -60,19 +60,19 @@ def get_exporter(format, **kwargs):
     try:
         from nbconvert.exporters.base import get_exporter
     except ImportError as e:
-        raise web.HTTPError(500, "Could not import nbconvert: %s" % e)
+        raise web.HTTPError(500, "Could not import nbconvert: %s" % e) from e
 
     try:
         Exporter = get_exporter(format)
-    except KeyError:
+    except KeyError as e:
         # should this be 400?
-        raise web.HTTPError(404, u"No exporter for format: %s" % format)
+        raise web.HTTPError(404, u"No exporter for format: %s" % format) from e
 
     try:
         return Exporter(**kwargs)
     except Exception as e:
         app_log.exception("Could not construct Exporter: %s", Exporter)
-        raise web.HTTPError(500, "Could not construct Exporter: %s" % e)
+        raise web.HTTPError(500, "Could not construct Exporter: %s" % e) from e
 
 
 class NbconvertFileHandler(JupyterHandler):
@@ -125,7 +125,7 @@ def get(self, format, path):
             )
         except Exception as e:
             self.log.exception("nbconvert failed: %s", e)
-            raise web.HTTPError(500, "nbconvert failed: %s" % e)
+            raise web.HTTPError(500, "nbconvert failed: %s" % e) from e
 
         if respond_zip(self, name, output, resources):
             return
@@ -162,7 +162,7 @@ def post(self, format):
                 "config_dir": self.application.settings['config_dir'],
             })
         except Exception as e:
-            raise web.HTTPError(500, "nbconvert failed: %s" % e)
+            raise web.HTTPError(500, "nbconvert failed: %s" % e) from e
 
         if respond_zip(self, name, output, resources):
             return

jupyter_server/services/contents/fileio.py

@@ -217,7 +217,7 @@ def perm_to_403(self, os_path=''):
                 if not os_path:
                     os_path = str_to_unicode(e.filename or 'unknown file')
                 path = to_api_path(os_path, root=self.root_dir)
-                raise HTTPError(403, u'Permission denied: %s' % path)
+                raise HTTPError(403, u'Permission denied: %s' % path) from e
             else:
                 raise
 
@@ -301,13 +301,13 @@ def _read_file(self, os_path, format):
             # was explicitly requested.
             try:
                 return bcontent.decode('utf8'), 'text'
-            except UnicodeError:
+            except UnicodeError as e:
                 if format == 'text':
                     raise HTTPError(
                         400,
                         "%s is not UTF-8 encoded" % os_path,
                         reason='bad format',
-                    )
+                    ) from e
         return encodebytes(bcontent).decode('ascii'), 'base64'
 
     def _save_file(self, os_path, content, format):
@@ -326,7 +326,7 @@ def _save_file(self, os_path, content, format):
         except Exception as e:
             raise HTTPError(
                 400, u'Encoding error saving %s: %s' % (os_path, e)
-            )
+            ) from e
 
         with self.atomic_writing(os_path, text=False) as f:
             f.write(bcontent)

jupyter_server/services/contents/filemanager.py

@@ -89,7 +89,8 @@ def run_post_save_hook(self, model, os_path):
                 self.post_save_hook(os_path=os_path, model=model, contents_manager=self)
             except Exception as e:
                 self.log.error("Post-save hook failed o-n %s", os_path, exc_info=True)
-                raise web.HTTPError(500, u'Unexpected error while running post hook save: %s' % e)
+                raise web.HTTPError(500, u'Unexpected error while running post hook save: %s' %
+                                    e) from e
 
     @validate('root_dir')
     def _validate_root_dir(self, proposal):
@@ -437,7 +438,8 @@ def save(self, model, path=''):
             raise
         except Exception as e:
             self.log.error(u'Error while saving file: %s %s', path, e, exc_info=True)
-            raise web.HTTPError(500, u'Unexpected error while saving file: %s %s' % (path, e))
+            raise web.HTTPError(500, u'Unexpected error while saving file: %s %s'
+                                % (path, e)) from e
 
         validation_message = None
         if model['type'] == 'notebook':
@@ -530,7 +532,8 @@ def rename_file(self, old_path, new_path):
         except web.HTTPError:
             raise
         except Exception as e:
-            raise web.HTTPError(500, u'Unknown error renaming file: %s %s' % (old_path, e))
+            raise web.HTTPError(500, u'Unknown error renaming file: %s %s' %
+                                (old_path, e)) from e
 
     def info_string(self):
         return _("Serving notebooks from local directory: %s") % self.root_dir

jupyter_server/services/contents/largefilemanager.py

@@ -35,7 +35,8 @@ def save(self, model, path=''):
                 raise
             except Exception as e:
                 self.log.error(u'Error while saving file: %s %s', path, e, exc_info=True)
-                raise web.HTTPError(500, u'Unexpected error while saving file: %s %s' % (path, e))
+                raise web.HTTPError(500, u'Unexpected error while saving file: %s %s' %
+                                    (path, e)) from e
 
             model = self.get(path, content=False)
 
@@ -62,7 +63,7 @@ def _save_large_file(self, os_path, content, format):
         except Exception as e:
             raise web.HTTPError(
                 400, u'Encoding error saving %s: %s' % (os_path, e)
-            )
+            ) from e
 
         with self.perm_to_403(os_path):
             if os.path.islink(os_path):

jupyter_server/services/kernelspecs/handlers.py

@@ -85,8 +85,8 @@ async def get(self, kernel_name):
         kernel_name = url_unescape(kernel_name)
         try:
             spec = await ensure_async(ksm.get_kernel_spec(kernel_name))
-        except KeyError:
-            raise web.HTTPError(404, u'Kernel spec %s not found' % kernel_name)
+        except KeyError as e:
+            raise web.HTTPError(404, u'Kernel spec %s not found' % kernel_name) from e
         if is_kernelspec_model(spec):
             model = spec
         else:

jupyter_server/services/nbconvert/handlers.py

@@ -12,7 +12,7 @@ def get(self):
         try:
             from nbconvert.exporters import base
         except ImportError as e:
-            raise web.HTTPError(500, "Could not import nbconvert: %s" % e)
+            raise web.HTTPError(500, "Could not import nbconvert: %s" % e) from e
         res = {}
         exporters = base.get_export_names()
         for exporter_name in exporters:

jupyter_server/services/sessions/handlers.py

@@ -42,13 +42,13 @@ async def post(self):
 
         try:
             path = model['path']
-        except KeyError:
-            raise web.HTTPError(400, "Missing field in JSON data: path")
+        except KeyError as e:
+            raise web.HTTPError(400, "Missing field in JSON data: path") from e
 
         try:
             mtype = model['type']
-        except KeyError:
-            raise web.HTTPError(400, "Missing field in JSON data: type")
+        except KeyError as e:
+            raise web.HTTPError(400, "Missing field in JSON data: type") from e
 
         name = model.get('name', None)
         kernel = model.get('kernel', {})
@@ -148,9 +148,9 @@ async def delete(self, session_id):
         sm = self.session_manager
         try:
             await sm.delete_session(session_id)
-        except KeyError:
+        except KeyError as e:
             # the kernel was deleted but the session wasn't!
-            raise web.HTTPError(410, "Kernel deleted before session")
+            raise web.HTTPError(410, "Kernel deleted before session") from e
         self.set_status(204)
         self.finish()