Refactor entrypoints (#28)

* Create utilities.get_parser

Factor out common logic into utilities.
Removes some dependencies and code duplications.

* Use parser in main()

See answer https://stackoverflow.com/questions/37697502/python-unittest-for-argparse
for reference.
Also updated docstrings

* Make testable as init

* Refactor and test init()

Using sys.exit as insurance that test call is executed correclty. #7

Needs import sys in module

* Refactored calls in tests to main

Now even simpler tests! No argparse.

* format

tdvisu/construct_dpdb_visu.py

@@ -27,6 +27,7 @@
 import argparse
 import json
 import logging
+import sys
 from datetime import datetime, timedelta
 from pathlib import Path
 from time import sleep
@@ -38,8 +39,7 @@
 from tdvisu.utilities import convert_to_adj
 from tdvisu.reader import TwReader
 from tdvisu.visualization import flatten
-from tdvisu.version import __date__, __version__ as version
-from tdvisu.utilities import read_yml_or_cfg, logging_cfg, LOGLEVEL_EPILOG
+from tdvisu.utilities import read_yml_or_cfg, logging_cfg, get_parser
 
 LOGGER = logging.getLogger('construct_dpdb_visu.py')
 
@@ -573,79 +573,69 @@ def create_json(
     return {}
 
 
-def main(args: argparse.Namespace) -> None:
+def main(args: List[str]) -> None:
     """
-    Main method running construct_dpdb_visu for arguments in 'args'
+    Main method running construct_dpdb_visu for arguments in 'args'.
 
     Parameters
     ----------
-    args : argparse.Namespace
-        The namespace containing all (command-line) parameters.
+    args : List[str]
+        The array containing all (command-line) flags.
 
     Returns
     -------
     None
     """
+    parser = get_parser("Extracts Information from "
+                        "https://github.com/hmarkus/dp_on_dbs runs "
+                        "for further visualization.")
 
-    logging_cfg(filename='logging.yml', loglevel=args.loglevel)
-    LOGGER.info("Called with '%s'", args)
+    parser.add_argument('problemnumber', type=int,
+                        help="selected problem-id in the postgres-database.")
+    parser.add_argument('--twfile',
+                        type=argparse.FileType('r', encoding='UTF-8'),
+                        help="tw-file containing the edges of the graph - "
+                        "obtained from dpdb with option --gr-file GR_FILE.")
+    parser.add_argument('--outfile', default='dbjson%d.json',
+                        help="default:'dbjson%%d.json'")
+    parser.add_argument('--pretty', action='store_true',
+                        help="pretty-print the JSON.")
+    parser.add_argument('--inter-nodes', action='store_true',
+                        help="calculate and animate the shortest path between "
+                        "successive bags in the order of evaluation.")
+    # get cmd-arguments
+    options = parser.parse_args(args)
 
-    problem_ = args.problemnumber
+    logging_cfg(filename='logging.yml', loglevel=options.loglevel)
+    LOGGER.info("Called with '%s'", options)
+    problem_ = options.problemnumber
     # get twfile if supplied
     try:
-        tw_file_ = args.twfile
+        tw_file_ = options.twfile
     except AttributeError:
         tw_file_ = None
+
+    # create JSON
     result_json = create_json(problem=problem_, tw_file=tw_file_)
-    # build json filename, can be supplied with problem-number
-    try:
-        outfile = args.outfile % problem_
+    try:    # build json filename, can be supplied with problem-number
+        outfile = options.outfile % problem_
     except TypeError:
-        outfile = args.outfile
+        outfile = options.outfile
     LOGGER.info("Output file-name: %s", outfile)
     with open(outfile, 'w') as file:
         json.dump(
             result_json,
             file,
             sort_keys=True,
-            indent=2 if args.pretty else None,
+            indent=2 if options.pretty else None,
             ensure_ascii=False)
         LOGGER.debug("Wrote to %s", file)
 
 
-if __name__ == "__main__":
-    # Parse args, call main
+def init():
+    """Initialization that is executed at the time of the module import."""
+    if __name__ == "__main__":
+        sys.exit(main(sys.argv[1:]))  # call main function
 
-    PARSER = argparse.ArgumentParser(
-        description="""
-        Copyright (C) 2020 Martin Röbke
-        This program comes with ABSOLUTELY NO WARRANTY
-        This is free software, and you are welcome to redistribute it
-        under certain conditions; see COPYING for more information.
 
-        Extracts Information from https://github.com/hmarkus/dp_on_dbs runs
-        for further visualization.""",
-        epilog=LOGLEVEL_EPILOG,
-        formatter_class=argparse.RawDescriptionHelpFormatter
-    )
-
-    PARSER.add_argument('problemnumber', type=int,
-                        help="selected problem-id in the postgres-database.")
-    PARSER.add_argument('--twfile',
-                        type=argparse.FileType('r', encoding='UTF-8'),
-                        help="tw-file containing the edges of the graph - "
-                        "obtained from dpdb with option --gr-file GR_FILE.")
-    PARSER.add_argument('--loglevel', help="set the minimal loglevel for root")
-    PARSER.add_argument('--outfile', default='dbjson%d.json',
-                        help="default:'dbjson%%d.json'")
-    PARSER.add_argument('--pretty', action='store_true',
-                        help="pretty-print the JSON.")
-    PARSER.add_argument('--inter-nodes', action='store_true',
-                        help="calculate and animate the shortest path between "
-                        "successive bags in the order of evaluation.")
-    PARSER.add_argument('--version', action='version',
-                        version='%(prog)s ' + version + ', ' + __date__)
-
-    # get cmd-arguments
-    _args = PARSER.parse_args()
-    main(_args)
+init()

tdvisu/utilities.py

@@ -20,16 +20,18 @@
     If not, see https://www.gnu.org/licenses/gpl-3.0.html
 
 """
-
+import argparse
 from collections.abc import Iterable as iter_type
 from configparser import ConfigParser, ParsingError, Error as CfgError
+from itertools import chain
 import logging
 import logging.config
-from itertools import chain
 from pathlib import Path
 from typing import Any, Generator, Iterable, Iterator, List, Tuple, TypeVar, Union
 import yaml
 
+from tdvisu.version import __date__, __version__
+
 LOGGER = logging.getLogger('utilities.py')
 
 CFG_EXT = ('.ini', '.cfg', '.conf', '.config')
@@ -446,3 +448,35 @@ def solution_node(
         result += '|' + bottomlabel
 
     return '{' + result + '}'
+
+
+def get_parser(extra_desc: str = '') -> argparse.ArgumentParser:
+    """
+    Prepare an argument parser for TDVisu scripts.
+
+    Parameters
+    ----------
+    extra_desc : str, optional
+        Description about the script using the parser. The default is ''.
+
+    Returns
+    -------
+    parser : argparse.ArgumentParser
+        The prepared argument parser object.
+
+    """
+    parser = argparse.ArgumentParser(
+        description="""
+        Copyright (C) 2020 Martin Röbke
+        This program comes with ABSOLUTELY NO WARRANTY
+        This is free software, and you are welcome to redistribute it
+        under certain conditions; see COPYING for more information.
+        """
+        + "\n" + extra_desc,
+        epilog=LOGLEVEL_EPILOG,
+        formatter_class=argparse.RawDescriptionHelpFormatter)
+
+    parser.add_argument('--version', action='version',
+                        version='%(prog)s ' + __version__ + ', ' + __date__)
+    parser.add_argument('--loglevel', help="set the minimal loglevel for root")
+    return parser

tdvisu/visualization.py

@@ -31,17 +31,16 @@
 import itertools
 import json
 import logging
+import sys
 from dataclasses import asdict
 from pathlib import Path
-from sys import stdin
 from typing import Iterable, List, Optional, Union, NewType
 
 from graphviz import Digraph, Graph
 from tdvisu.visualization_data import (VisualizationData, IncidenceGraphData,
                                        GeneralGraphData, SvgJoinData)
-from tdvisu.version import __date__, __version__ as version
 from tdvisu.svgjoin import svg_join
-from tdvisu.utilities import flatten, LOGLEVEL_EPILOG, logging_cfg
+from tdvisu.utilities import flatten, logging_cfg, get_parser
 from tdvisu.utilities import bag_node, solution_node, base_style
 from tdvisu.utilities import style_hide_edge, style_hide_node, emphasise_node
 
@@ -699,25 +698,38 @@ def call_svgjoin(self) -> None:
             svg_join(**asdict(sj_data))
 
 
-def main(args: argparse.Namespace) -> None:
+def main(args: List[str]) -> None:
     """
-    Main method running construct_dpdb_visu for arguments in 'args'
+    Main method running visualization for arguments in 'args'.
 
     Parameters
     ----------
-    args : argparse.Namespace
-        The namespace containing all (command-line) parameters.
+    args : List[str]
+        The array containing all (command-line) flags.
 
     Returns
     -------
     None
     """
+    parser = get_parser(
+        "Visualizing Dynamic Programming on Tree-Decompositions.")
+    # possible to use stdin for the file.
+    parser.add_argument('infile', nargs='?',
+                        type=argparse.FileType('r', encoding='UTF-8'),
+                        default=sys.stdin,
+                        help="Input file for the visualization "
+                        "must conform with the 'JsonAPI.md'")
+    parser.add_argument('outfolder',
+                        help="Folder to output the visualization results")
+
+    # get cmd-arguments
+    options = parser.parse_args(args)
 
-    logging_cfg(filename='logging.yml', loglevel=args.loglevel)
-    LOGGER.info("Called with '%s'", args)
+    logging_cfg(filename='logging.yml', loglevel=options.loglevel)
+    LOGGER.info("Called with '%s'", options)
 
-    infile = args.infile
-    outfolder = args.outfolder
+    infile = options.infile
+    outfolder = options.outfolder
     if not outfolder:
         outfolder = 'outfolder'
     outfolder = Path(outfolder).resolve()
@@ -728,33 +740,10 @@ def main(args: argparse.Namespace) -> None:
     visu.tree_dec_timeline()
 
 
-if __name__ == "__main__":
-    # Parse args, call main
-
-    PARSER = argparse.ArgumentParser(
-        description="""
-        Copyright (C) 2020 Martin Röbke
-        This program comes with ABSOLUTELY NO WARRANTY
-        This is free software, and you are welcome to redistribute it
-        under certain conditions; see COPYING for more information.
+def init():
+    """Initialization that is executed at the time of the module import."""
+    if __name__ == "__main__":
+        sys.exit(main(sys.argv[1:]))  # call main function
 
-        Visualizing Dynamic Programming on Tree-Decompositions.""",
-        epilog=LOGLEVEL_EPILOG,
-        formatter_class=argparse.RawDescriptionHelpFormatter)
 
-    # possible to use stdin for the file.
-    PARSER.add_argument('infile', nargs='?',
-                        type=argparse.FileType('r', encoding='UTF-8'),
-                        default=stdin,
-                        help="Input file for the visualization "
-                        "must conform with the 'JsonAPI.md'")
-    PARSER.add_argument('outfolder',
-                        help="Folder to output the visualization results")
-    PARSER.add_argument('--version', action='version',
-                        version='%(prog)s ' + version + ', ' + __date__)
-    PARSER.add_argument('--loglevel', help="set the minimal loglevel for root")
-
-    # get cmd-arguments
-    _args = PARSER.parse_args()
-    # call main()
-    main(_args)
+init()

test/test_construct_dpdb.py

@@ -21,12 +21,11 @@
 
 """
 
-import argparse
 import datetime
 
 from pathlib import Path
 import psycopg2 as pg
-
+from tdvisu import construct_dpdb_visu as module
 from tdvisu.construct_dpdb_visu import (read_cfg, db_config, DEFAULT_DBCONFIG,
                                         IDpdbVisuConstruct, DpdbSharpSatVisu,
                                         DpdbSatVisu, DpdbMinVcVisu, main)
@@ -137,28 +136,10 @@ def test_main(mocker, tmp_path):
     query_edgearray = mocker.patch(
         'tdvisu.construct_dpdb_visu.query_edgearray', return_value=[
             (2, 1), (3, 2), (4, 2), (5, 4)])
-
-    parser = argparse.ArgumentParser()
-    parser.add_argument('problemnumber', type=int,
-                        help="selected problem-id in the postgres-database.")
-    parser.add_argument('--twfile',
-                        type=argparse.FileType('r', encoding='UTF-8'),
-                        help="tw-file containing the edges of the graph - "
-                        "obtained from dpdb with option --gr-file GR_FILE.")
-    parser.add_argument('--loglevel', help="set the minimal loglevel for root")
-    parser.add_argument('--outfile', default='dbjson%d.json',
-                        help="default:'dbjson%%d.json'")
-    parser.add_argument('--pretty', action='store_true',
-                        help="pretty-print the JSON.")
-    parser.add_argument('--inter-nodes', action='store_true',
-                        help="calculate and animate the shortest path between "
-                        "successive bags in the order of evaluation.")
-
     # set cmd-arguments
     outfile = str(tmp_path / 'test_main.json')
-    _args = parser.parse_args(['1', '--outfile', outfile])
     # one mocked run
-    main(_args)
+    main(['1', '--outfile', outfile])
 
     # Assertions
     mock_connect.assert_called_once()
@@ -172,3 +153,15 @@ def test_main(mocker, tmp_path):
     assert query_column_name.call_count == 5
     assert query_td_bag.call_count == 5
     assert query_td_node_status.call_count == 5
+
+
+def test_init(mocker):
+    """Test that main is called correctly if called as __main__."""
+    expected = -1000
+    main = mocker.patch.object(module, "main", return_value=expected)
+    mock_exit = mocker.patch.object(module.sys, 'exit')
+    mocker.patch.object(module, "__name__", "__main__")
+    module.init()
+
+    main.assert_called_once()
+    assert mock_exit.call_args[0][0] == expected