better exception handling

Author: AddisonSchiller

mfr/extensions/tabular/libs/stdlib_tools.py

@@ -3,7 +3,8 @@
 from http import HTTPStatus
 
 from mfr.extensions.tabular import utilities
-from mfr.extensions.tabular.exceptions import EmptyTableError, TabularRendererError
+from mfr.extensions.tabular.exceptions import (EmptyTableError,
+                                               TabularRendererError)
 
 
 def csv_stdlib(fp):
@@ -73,6 +74,14 @@ def parse_stdlib(reader):
                                        code=HTTPStatus.BAD_REQUEST,
                                        extension='csv') from e
 
+    # Outside other except because the `if any` line causes more errors to be raised
+    # on certain exceptions
+    except UnicodeDecodeError as e:
+        raise TabularRendererError('Cannot render file as csv/tsv. '
+                           'The file may be empty or corrupt',
+                           code=HTTPStatus.BAD_REQUEST,
+                           extension='csv') from e
+
     if not columns and not rows:
         raise EmptyTableError('Cannot render file as csv/tsv. '
                               'The file may be empty or corrupt',

tests/extensions/tabular/files/invalid_null.csv

@@ -4,8 +4,8 @@
 import pytest
 
 from mfr.extensions.tabular.libs import stdlib_tools
-from mfr.extensions.tabular.exceptions import EmptyTableError
-
+from mfr.extensions.tabular.exceptions import(EmptyTableError,
+                                              TabularRendererError)
 
 BASE = os.path.dirname(os.path.abspath(__file__))
 
@@ -49,3 +49,9 @@ def test_csv_stdlib_exception_raises(self):
             with pytest.raises(EmptyTableError) as e:
                 stdlib_tools.tsv_stdlib(fp)
                 assert e.value.code == 400
+
+    def test_csv_stdlib_other_exception_raises(self):
+        with open(os.path.join(BASE, 'files', 'invalid_null.csv')) as fp:
+            with pytest.raises(TabularRendererError) as e:
+                stdlib_tools.tsv_stdlib(fp)
+                assert e.value.code == 400