Change pytest tests to handle empty dbf fields

shapefile.py

@@ -747,7 +747,7 @@ def __init__(self, *args, **kwargs):
                     self.dbf.seek(0)
                 except (NameError, io.UnsupportedOperation):
                     self.dbf = io.BytesIO(self.dbf.read())
-        if self.shp or self.dbf:        
+        if self.shp or self.dbf:
             self.load()
         else:
             raise ShapefileException("Shapefile Reader requires a shapefile or file-like object.")
@@ -1670,7 +1670,7 @@ def record(self, *recordList, **recordDict):
         """Creates a dbf attribute record. You can submit either a sequence of
         field values or keyword arguments of field names and values. Before
         adding records you must add fields for the record values using the
-        fields() method. If the record values exceed the number of fields the
+        field() method. If the record values exceed the number of fields the
         extra ones won't be added. In the case of using keyword arguments to specify
         field/value pairs only fields matching the already registered fields
         will be added."""

test_shapefile.py

@@ -227,7 +227,7 @@ def test_write_dbf_only(tmpdir):
     """
     filename = tmpdir.join("test.dbf").strpath
     with shapefile.Writer(dbf=filename) as writer:
-        pass
+        writer.field('field1', 'C') # required to create a valid dbf file
 
     # assert test.dbf exists
     assert os.path.exists(filename)
@@ -247,7 +247,7 @@ def test_write_default_shp_shx_dbf(tmpdir):
     """
     filename = tmpdir.join("test").strpath
     with shapefile.Writer(filename) as writer:
-        pass
+        writer.field('field1', 'C') # required to create a valid dbf file
 
     # assert shp, shx, dbf files exist
     assert os.path.exists(filename + ".shp")
@@ -264,7 +264,7 @@ def test_write_shapefile_extension_ignored(tmpdir):
     ext = ".abc"
     filename = tmpdir.join(base + ext).strpath
     with shapefile.Writer(filename) as writer:
-        pass
+        writer.field('field1', 'C') # required to create a valid dbf file
 
     # assert shp, shx, dbf files exist
     basepath = tmpdir.join(base).strpath