require_existing=True by default

(see wq/django-data-wizard#33)
wq · Nov 18, 2021 · b7b5ddc · b7b5ddc
1 parent 81c6aca
commit b7b5ddc
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Showing 6 changed files with 45 additions and 5 deletions.
diff --git a/itertable/gis/mixins.py b/itertable/gis/mixins.py
@@ -1,6 +1,7 @@
 import fiona
 from shapely import wkt, geometry
 from ..loaders import FileLoader
+from ..exceptions import LoadFailed
 from ..parsers.base import BaseParser
 from ..mappers import TupleMapper
 
@@ -16,7 +17,22 @@ class FionaLoaderParser(FileLoader, BaseParser):
     def load(self):
         try:
             self.layers = fiona.listlayers(self.filename)
-        except (ValueError, IOError):
+        except OSError as e:
+            if self.require_existing:
+                raise LoadFailed(
+                    e.strerror,
+                    path=self.filename,
+                    code=e.errno,
+                )
+            else:
+                self.empty_file = True
+        except ValueError as e:
+            if self.require_existing:
+                raise LoadFailed(str(e))
+            else:
+                self.empty_file = True
+
+        if self.empty_file:
             driver = guess_driver(self.filename)
             self.meta = {'driver': driver}
             self.empty_file = True

diff --git a/itertable/loaders.py b/itertable/loaders.py
@@ -16,6 +16,7 @@ def load(self):
 
 class FileLoader(BaseLoader):
     filename = None
+    require_existing = True
 
     @property
     def read_mode(self):
@@ -29,8 +30,14 @@ def load(self):
         try:
             self.file = open(self.filename, self.read_mode)
             self.empty_file = False
-        except IOError:
-            if self.binary:
+        except OSError as e:
+            if self.require_existing:
+                raise LoadFailed(
+                    e.strerror,
+                    path=self.filename,
+                    code=e.errno,
+                )
+            elif self.binary:
                 self.file = BytesIO()
             else:
                 self.file = StringIO()

diff --git a/tests/files/nodata.csv b/tests/files/nodata.csv
diff --git a/tests/test_gis.py b/tests/test_gis.py
@@ -24,7 +24,9 @@ def test_shapeio_sync(self):
                 source_file = self.get_filename("test", source_ext)
                 dest_file = self.get_filename("sync", dest_ext, True)
                 source_instance = ShapeIter(filename=source_file)
-                dest_instance = ShapeIter(filename=dest_file)
+                dest_instance = ShapeIter(
+                    filename=dest_file, require_existing=False
+                )
                 source_instance.sync(dest_instance)
                 self.check_instance(ShapeIter(filename=dest_file))
 

diff --git a/tests/test_load_file.py b/tests/test_load_file.py
@@ -1,5 +1,5 @@
 from itertable import load_file
-from itertable.exceptions import NoData
+from itertable.exceptions import LoadFailed, NoData
 from .base import IterTestCase
 import pickle
 
@@ -40,6 +40,19 @@ def test_load_nodata(self):
             instance[0]
         self.assertEqual(str(cm.exception), "No data returned!")
 
+    def test_load_non_existing(self):
+        filename = self.get_filename("nonexisting", "csv")
+        with self.assertRaises(LoadFailed) as cm:
+            load_file(filename)
+        self.assertEqual(str(cm.exception), "No such file or directory")
+
+    def test_load_init_empty(self):
+        filename = self.get_filename("nonexisting", "csv")
+        instance = load_file(filename, options={'require_existing': False})
+        with self.assertRaises(NoData) as cm:
+            instance[0]
+        self.assertEqual(str(cm.exception), "No data returned!")
+
     def test_pickle(self):
         for ext in self.types:
             filename = self.get_filename("test", ext)

diff --git a/tests/test_write.py b/tests/test_write.py
@@ -35,6 +35,7 @@ def test_write_file(self):
             # Create an empty instance of the class
             instance = cls(
                 filename=filename,
+                require_existing=False,
                 field_names=['one', 'two', 'three'],
 
                 # These only apply to XmlFileIter, will be ignored by others
@@ -72,6 +73,7 @@ def duplicate(self, mode, xform):
                 # Create empty instance of the destination Iter class
                 dest_instance = dest_cls(
                     filename=dest_file,
+                    require_existing=False,
                     field_names=['one', 'two', 'three'],
                     root_tag="root",
                     item_tag="item",