Issue #469 is fixed (When run on Windows a lot of tests fail with the error: [Errno 13] Permission denied) (#484)

Closes #469

* Issue #469 is fixed

* one extra comment to code is added

* TemporaryFilePath context manager is added to facilitate tests

* flake8 complaints fixed

* Update docs of tempfilepath.py

* Fix flake8

Co-authored-by: Pieter Marsman <pietermarsman@gmail.com>

CHANGELOG.md

@@ -3,10 +3,12 @@ All notable changes in pdfminer.six will be documented in this file.
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
+
 ## [Unreleased]
 
 ### Fixed
 - Fix issue of TypeError: cannot unpack non-iterable PDFObjRef object, when unpacking the value of 'DW2' ([#529](https://github.com/pdfminer/pdfminer.six/pull/529))
+- `PermissionError` when creating temporary filepaths on windows when running tests ([#469](https://github.com/pdfminer/pdfminer.six/issues/469))
 
 ## Removed
 - Support for Python 3.4 and 3.5 ([#522](https://github.com/pdfminer/pdfminer.six/pull/522))

tests/tempfilepath.py

@@ -0,0 +1,58 @@
+"""Helper module, which provides a TemporaryFilePath() context manager"""
+
+import tempfile
+import os
+
+
+class TemporaryFilePath():
+    """Context manager class, which generates temporary file name
+
+    Coonroraly to standard tempfile.NamedTemporaryFile(), it does not
+    create file. Upon exit from the context manager block, it will
+    attempt to delete the file with the generated file name.
+
+    Example:
+
+        >>> with TemporaryFilePath() as temp_file_name:
+        >>>    with open(temp_file_name, "w") as temp_file:
+        >>>        temp_file.write("some test data, which goes to the file")
+        >>>        # some test code is here which reads data out of temp_file
+
+    Args:
+        suffix: If 'suffix' is not None, the file name will end with that
+            suffix, otherwise there will be no suffix.
+        prefix: If 'prefix' is not None, the file name will begin with that
+            prefix, otherwise a default prefix is used.
+        dir: If 'dir' is not None, the file will be created in that directory,
+            otherwise a default directory is used.
+        delete: whether the file is deleted at the end (default True)
+    """
+
+    def __init__(self, suffix=None, prefix=None, dir=None, delete=True):
+        self.suffix = suffix
+        self.prefix = prefix
+        self.dir = dir
+        self.delete = delete
+
+    def __enter__(self) -> str:
+        """Create temporary file path
+
+        `tempfile.NamedTemporaryFile` will create and delete a file, and
+        this method only returns the filepath of the non-existing file.
+        """
+        with tempfile.NamedTemporaryFile(suffix=self.suffix,
+                                         prefix=self.prefix,
+                                         dir=self.dir) as file:
+            self.temp_file_name = file.name
+
+        return self.temp_file_name
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        if self.delete:
+            try:
+                os.remove(self.temp_file_name)
+
+            # Exception 'FileNotFoundError' is acceptable as user may have not
+            # created the file to start with or has deleted it himself
+            except FileNotFoundError:
+                pass

tests/test_tools_dumppdf.py

@@ -1,19 +1,20 @@
 import warnings
-from tempfile import NamedTemporaryFile
 
 from helpers import absolute_sample_path
+from tempfilepath import TemporaryFilePath
 from pdfminer.pdfdocument import PDFNoValidXRefWarning
 from tools import dumppdf
 
 
 def run(filename, options=None):
     absolute_path = absolute_sample_path(filename)
-    with NamedTemporaryFile() as output_file:
+    with TemporaryFilePath() as output_file_name:
         if options:
-            s = 'dumppdf -o %s %s %s' % (output_file.name,
+            s = 'dumppdf -o %s %s %s' % (output_file_name,
                                          options, absolute_path)
         else:
-            s = 'dumppdf -o %s %s' % (output_file.name, absolute_path)
+            s = 'dumppdf -o %s %s' % (output_file_name, absolute_path)
+
         dumppdf.main(s.split(' ')[1:])
 
 

tests/test_tools_pdf2txt.py

@@ -1,19 +1,21 @@
 import os
 from shutil import rmtree
-from tempfile import NamedTemporaryFile, mkdtemp
+from tempfile import mkdtemp
 
 import tools.pdf2txt as pdf2txt
 from helpers import absolute_sample_path
+from tempfilepath import TemporaryFilePath
 
 
 def run(sample_path, options=None):
     absolute_path = absolute_sample_path(sample_path)
-    with NamedTemporaryFile() as output_file:
+    with TemporaryFilePath() as output_file_name:
         if options:
             s = 'pdf2txt -o{} {} {}' \
-                .format(output_file.name, options, absolute_path)
+                .format(output_file_name, options, absolute_path)
         else:
-            s = 'pdf2txt -o{} {}'.format(output_file.name, absolute_path)
+            s = 'pdf2txt -o{} {}'.format(output_file_name, absolute_path)
+
         pdf2txt.main(s.split(' ')[1:])
 
 
@@ -109,8 +111,8 @@ class TestDumpImages:
     @staticmethod
     def extract_images(input_file):
         output_dir = mkdtemp()
-        with NamedTemporaryFile() as output_file:
-            commands = ['-o', output_file.name, '--output-dir',
+        with TemporaryFilePath() as output_file_name:
+            commands = ['-o', output_file_name, '--output-dir',
                         output_dir, input_file]
             pdf2txt.main(commands)
         image_files = os.listdir(output_dir)