Added set_color_library class method to TableColors

This allows the ability to manually override which color library is being used, which is necessary to ensure reproducible unit tests regardless of what color libraries are installed.

Added the first bare-bones template for unit tests with a single test to start.

Author: tleonhardt

tableformatter.py

@@ -303,6 +303,44 @@ class TableColors(object):
             BOLD = ''
             RESET = ''
 
+    @classmethod
+    def set_color_library(cls, library_name: str) -> None:
+        """Manually override the color library being used."""
+        if library_name == 'colored':
+            from colored import fg, bg, attr
+
+            cls.TEXT_COLOR_WHITE = fg('white')
+            cls.TEXT_COLOR_YELLOW = fg(226)
+            cls.TEXT_COLOR_RED = fg(196)
+            cls.TEXT_COLOR_GREEN = fg(119)
+            cls.TEXT_COLOR_BLUE = fg(27)
+            cls.BG_COLOR_ROW = bg(234)
+            cls.BG_RESET = bg(0)
+            cls.BOLD = attr('bold')
+            cls.RESET = attr('reset')
+        elif library_name == 'colorama':
+            from colorama import Fore, Back, Style
+
+            cls.TEXT_COLOR_WHITE = Fore.WHITE
+            cls.TEXT_COLOR_YELLOW = Fore.LIGHTYELLOW_EX
+            cls.TEXT_COLOR_RED = Fore.LIGHTRED_EX
+            cls.TEXT_COLOR_GREEN = Fore.LIGHTGREEN_EX
+            cls.TEXT_COLOR_BLUE = Fore.LIGHTBLUE_EX
+            cls.BG_COLOR_ROW = Back.LIGHTBLACK_EX
+            cls.BG_RESET = Back.RESET
+            cls.BOLD = Style.BRIGHT
+            cls.RESET = Fore.RESET + Back.RESET
+        else:
+            cls.TEXT_COLOR_WHITE = ''
+            cls.TEXT_COLOR_YELLOW = ''
+            cls.TEXT_COLOR_RED = ''
+            cls.TEXT_COLOR_GREEN = ''
+            cls.TEXT_COLOR_BLUE = ''
+            cls.BG_COLOR_ROW = ''
+            cls.BG_RESET = ''
+            cls.BOLD = ''
+            cls.RESET = ''
+
 
 class ColumnAlignment(enum.Enum):
     """Column alignment"""

tests/test_simple_object.py

@@ -0,0 +1,48 @@
+# coding=utf-8
+"""
+Unit testing of tableformatter with simple cases using a list of objects for the table entries.
+"""
+import pytest
+
+import tableformatter as tf
+
+
+class MyRowObject(object):
+    """Simple object to demonstrate using a list of objects with TableFormatter"""
+    def __init__(self, field1: str, field2: str, field3: str, field4: str):
+        self.field1 = field1
+        self.field2 = field2
+        self._field3 = field3
+        self.field4 = field4
+
+    def get_field3(self):
+        """Demonstrates accessing object functions"""
+        return self._field3
+
+
+# Make the test results reproducible regardless of what color libraries are installed
+tf.TableColors.set_color_library('none')
+
+
+@pytest.fixture
+def rows():
+    r = [MyRowObject('A1', 'A2', 'A3', 'A4'),
+         MyRowObject('B1', 'B2\nB2\nB2', 'B3', 'B4'),
+         MyRowObject('C1', 'C2', 'C3', 'C4'),
+         MyRowObject('D1', 'D2', 'D3', 'D4')]
+    return r
+
+
+@pytest.fixture
+def cols():
+    columns = (tf.Column('Col1', attrib='field1'),
+               tf.Column('Col2', attrib='field2'),
+               tf.Column('Col3', attrib='get_field3'),
+               tf.Column('Col4', attrib='field4'))
+    return columns
+
+
+def test_object_table_with_header(rows, cols):
+    expected = '╔══════╤══════╤══════╤══════╗\n║ Col1 │ Col2 │ Col3 │ Col4 ║\n╠══════╪══════╪══════╪══════╣\n║ A1   │ A2   │ A3   │ A4   ║\n║ B1   │ B2   │ B3   │ B4   ║\n║      │ B2   │      │      ║\n║      │ B2   │      │      ║\n║ C1   │ C2   │ C3   │ C4   ║\n║ D1   │ D2   │ D3   │ D4   ║\n╚══════╧══════╧══════╧══════╝\n'
+    table = tf.generate_table(rows, cols)
+    assert table == expected