Group pytest's tests (elementary, files).

The introduction of a pytest.ini appears as a convienient approach
to group tests of pytests sharing an element in common.  This seems
beneficial as long as there is no reliable approch identified to
stack "file" and "folder" as levels of an additional parameter in
theses tests for date2name.

By now, the two layers "elementary" and "files" are installed.

pytest.ini

@@ -0,0 +1,5 @@
+[pytest]
+markers =
+    elementary:  elementary tests ahead of action on files/folders by date2name
+    files:       tests about affect by date2name on files
+    folders:     tests about affect by date2name on folders

test_date2name.py

@@ -64,6 +64,7 @@ def query_modification_time(name=TFILE):
     modified = str(datetime.fromtimestamp(modified))
     return modified
 
+@pytest.mark.elementary
 def test_create_remove_testfile(name=TFILE):
     """Merely check if the test file may be written and removed."""
     prepare_testfile(name=TFILE)
@@ -72,6 +73,7 @@ def test_create_remove_testfile(name=TFILE):
     assert os.path.isfile(name) is False
 
 
+@pytest.mark.elementary    
 def test_create_remove_testfolder(name=TFOLDER):
     """Probe the generation/removal of a test folder."""
     prepare_testfolder(name=TFOLDER)
@@ -80,11 +82,13 @@ def test_create_remove_testfolder(name=TFOLDER):
     assert os.path.isdir(name) is False
 
 
+@pytest.mark.elementary
 def test_script_existence():
     """Merely check for the script's presence."""
     assert os.path.isfile(PROGRAM)
 
 
+@pytest.mark.elementary    
 def test_script_version():
     """Check for the correct output of the version.
 
@@ -92,6 +96,7 @@ def test_script_version():
     out = getoutput(f"python3 {PROGRAM} --version")
     assert out.strip() == "__init__.py 2018-05-09"
 
+@pytest.mark.files
 @pytest.mark.parametrize("arg1", [" ", "-f", "--files",
                                   "-m", "--mtime",
                                   "-c", "--ctime"])
@@ -112,6 +117,7 @@ def test_file_pattern_default(arg1):
     assert os.path.isfile(new)
     os.remove(new)
 
+@pytest.mark.files
 @pytest.mark.parametrize("arg1", ["-C", "--compact",
                                   "-C -f", "--compact -f",
                                   "-C --files", "--compact --files",
@@ -144,6 +150,7 @@ def test_file_pattern_compact(arg1):
     assert os.path.isfile(new)
     os.remove(new)
 
+@pytest.mark.files
 @pytest.mark.parametrize("arg1", ["-M", "--month",
                                   "-M -f", "--month -f",
                                   "-M --files", "--month --files",
@@ -176,6 +183,7 @@ def test_file_pattern_month(arg1):
     assert os.path.isfile(new)
     os.remove(new)
 
+@pytest.mark.files
 @pytest.mark.parametrize("arg1", ["-w -f", "-w --files",
                                   "--withtime -f", "--withtime --files",
                                   "-w -m", "-w --mtime",
@@ -209,6 +217,7 @@ def test_file_pattern_withtime(arg1):
     assert os.path.isfile(new)
     os.remove(new)
 
+@pytest.mark.files
 @pytest.mark.parametrize("arg1", ["-S", "--short",
                                   "-S -f", "--short -f",
                                   "-S --files", "--short --files",
@@ -243,6 +252,7 @@ def test_file_pattern_short(arg1):
     assert os.path.isfile(new)
     os.remove(new)
 
+@pytest.mark.files
 @pytest.mark.parametrize("arg1", ["default", "short", "compact",
                                   "month", "withtime"])
 @pytest.mark.parametrize("arg2", ["-r", "--remove"])

test_generator.org

@@ -81,6 +81,31 @@
       pytest-3 -v test_date2name.py   # pytest if Python 2 and Python 3 coexist
     #+end_src
 
+** Building a pytest.ini
+
+   This file defines markers which groups the tests into groups.  Subsequently,
+   tests with pytest may focus on them rather than performing all tests (which
+   is set up as the default).  In presence of =pytest.ini=, the typical call
+   then is
+   #+begin_src bash  :tangle no
+     pytest-3 test_date2name.py -v -m "elementary"
+   #+end_src
+   to constrain the tester's action to all tests labeled as "elementary".  At
+   present, tests are grouped as
+   + elementary; ahead of checking date2name's action on files or folders
+   + files; checking date2name's action on files, and
+   + folders; checking date2name's action on folders.
+   This became necessary since a reliable approach to stack the levels "files"
+   and "folders" in this testing suite was not yet identified.
+     
+
+   #+begin_src python :tangle pytest.ini
+     [pytest]
+     markers =
+         elementary:  elementary tests ahead of action on files/folders by date2name
+         files:       tests about affect by date2name on files
+         folders:     tests about affect by date2name on folders
+   #+end_src
 
 ** Building the test script
 
@@ -166,6 +191,7 @@
     These tests do not modify a file, nor folder by =date2time=.
 
     #+begin_src python :tangle test_date2name.py
+      @pytest.mark.elementary
       def test_create_remove_testfile(name=TFILE):
           """Merely check if the test file may be written and removed."""
           prepare_testfile(name=TFILE)
@@ -173,7 +199,8 @@
           os.remove(name)
           assert os.path.isfile(name) is False
       
-          
+      
+      @pytest.mark.elementary    
       def test_create_remove_testfolder(name=TFOLDER):
           """Probe the generation/removal of a test folder."""
           prepare_testfolder(name=TFOLDER)
@@ -181,12 +208,14 @@
           os.rmdir(name)
           assert os.path.isdir(name) is False
       
-          
+      
+      @pytest.mark.elementary
       def test_script_existence():
           """Merely check for the script's presence."""
           assert os.path.isfile(PROGRAM)
       
       
+      @pytest.mark.elementary    
       def test_script_version():
           """Check for the correct output of the version.
       
@@ -202,6 +231,7 @@
 
     + [X] default pattern, i.e. prepend YYYY-MM-DD_ to file test.txt
       #+begin_src python :tangle test_date2name.py
+        @pytest.mark.files
         @pytest.mark.parametrize("arg1", [" ", "-f", "--files",
                                           "-m", "--mtime",
                                           "-c", "--ctime"])
@@ -227,6 +257,7 @@
       This may re-use much of the instructions used for the default pattern
       and only needs to drop the hyphens.
       #+begin_src python :tangle test_date2name.py
+        @pytest.mark.files
         @pytest.mark.parametrize("arg1", ["-C", "--compact",
                                           "-C -f", "--compact -f",
                                           "-C --files", "--compact --files",
@@ -264,6 +295,7 @@
       Departing from the standard format YYYY-MM-DD, it suffices to trim
       off the last three characters.
       #+begin_src python :tangle test_date2name.py
+        @pytest.mark.files
         @pytest.mark.parametrize("arg1", ["-M", "--month",
                                           "-M -f", "--month -f",
                                           "-M --files", "--month --files",
@@ -300,6 +332,7 @@
     + [X] To prepend date and time to file test.txt in a pattern of
       YYYY-MM-DDThh.mm.ss, the default pattern YYYY-MM-DD is extended.
       #+begin_src python :tangle test_date2name.py
+        @pytest.mark.files
         @pytest.mark.parametrize("arg1", ["-w -f", "-w --files",
                                           "--withtime -f", "--withtime --files",
                                           "-w -m", "-w --mtime",
@@ -338,6 +371,7 @@
       Related to the basic pattern, except truncating of the first two
       characters.
       #+begin_src python :tangle test_date2name.py
+        @pytest.mark.files
         @pytest.mark.parametrize("arg1", ["-S", "--short",
                                           "-S -f", "--short -f",
                                           "-S --files", "--short --files",
@@ -383,6 +417,7 @@
       successful to retract this stamp.
       
       #+begin_src python :tangle test_date2name.py
+        @pytest.mark.files
         @pytest.mark.parametrize("arg1", ["default", "short", "compact",
                                           "month", "withtime"])
         @pytest.mark.parametrize("arg2", ["-r", "--remove"])