Adding unit tests for text alignment functions

Author: kmvanbrunt

cmd2/utils.py

@@ -642,7 +642,7 @@ def align_text(text: str, *, fill_char: str = ' ', width: Optional[int] = None,
     """
     Align text for display within a given width. Supports characters with display widths greater than 1.
     ANSI escape sequences are safely ignored and do not count toward the display width. This means colored text is
-    supported. Each line in text will be aligned independently.
+    supported. If text has line breaks, then each line is aligned independently.
 
     There are convenience wrappers around this function: ljustify_text(), center_text(), and rjustify_text()
 
@@ -653,22 +653,21 @@ def align_text(text: str, *, fill_char: str = ' ', width: Optional[int] = None,
                       be converted to a space.
     :param alignment: how to align the text
     :return: aligned text
-    :raises: ValueError if text or fill_char contains an unprintable character
-             TypeError if fill_char is more than one character
-
+    :raises: TypeError if fill_char is more than one character
+             ValueError if text or fill_char contains an unprintable character
     """
     import io
     import shutil
 
     from . import ansi
 
     # Handle tabs
-    text.replace('\t', ' ' * tab_width)
+    text = text.replace('\t', ' ' * tab_width)
     if fill_char == '\t':
         fill_char = ' '
 
     if len(fill_char) != 1:
-        raise ValueError("Fill character must be exactly one character long")
+        raise TypeError("Fill character must be exactly one character long")
 
     fill_char_width = ansi.ansi_safe_wcswidth(fill_char)
     if fill_char_width == -1:
@@ -679,22 +678,21 @@ def align_text(text: str, *, fill_char: str = ' ', width: Optional[int] = None,
     else:
         lines = ['']
 
+    if width is None:
+        width = shutil.get_terminal_size().columns
+
     text_buf = io.StringIO()
 
     for index, line in enumerate(lines):
         if index > 0:
             text_buf.write('\n')
 
-        # Use ansi_safe_wcswidth to support characters with display widths greater than 1
-        # as well as ANSI escape sequences
+        # Use ansi_safe_wcswidth to support characters with display widths
+        # greater than 1 as well as ANSI escape sequences
         line_width = ansi.ansi_safe_wcswidth(line)
         if line_width == -1:
-            # This can happen if text contains characters like newlines or tabs
             raise(ValueError("Text to align contains an unprintable character"))
 
-        if width is None:
-            width = shutil.get_terminal_size().columns
-
         # Check if line is wider than the desired final width
         if width <= line_width:
             text_buf.write(line)
@@ -731,7 +729,7 @@ def ljustify_text(text: str, *, fill_char: str = ' ', width: Optional[int] = Non
     """
     Left justify text for display within a given width. Supports characters with display widths greater than 1.
     ANSI escape sequences are safely ignored and do not count toward the display width. This means colored text is
-    supported. Each line in text will be aligned independently.
+    supported. If text has line breaks, then each line is aligned independently.
 
     :param text: text to left justify (Can contain multiple lines)
     :param fill_char: character that fills the alignment gap. Defaults to space. (Cannot be a line breaking character)
@@ -748,7 +746,7 @@ def center_text(text: str, *, fill_char: str = ' ', width: Optional[int] = None,
     """
     Center text for display within a given width. Supports characters with display widths greater than 1.
     ANSI escape sequences are safely ignored and do not count toward the display width. This means colored text is
-    supported. Each line in text will be aligned independently.
+    supported. If text has line breaks, then each line is aligned independently.
 
     :param text: text to center (Can contain multiple lines)
     :param fill_char: character that fills the alignment gap. Defaults to space. (Cannot be a line breaking character)
@@ -765,7 +763,7 @@ def rjustify_text(text: str, *, fill_char: str = ' ', width: Optional[int] = Non
     """
     Right justify text for display within a given width. Supports characters with display widths greater than 1.
     ANSI escape sequences are safely ignored and do not count toward the display width. This means colored text is
-    supported. Each line in text will be aligned independently.
+    supported. If text has line breaks, then each line is aligned independently.
 
     :param text: text to right justify (Can contain multiple lines)
     :param fill_char: character that fills the alignment gap. Defaults to space. (Cannot be a line breaking character)

tests/test_utils.py

@@ -293,21 +293,157 @@ def test_context_flag_exit_err(context_flag):
         context_flag.__exit__()
 
 
-def test_center_text_pad_equals():
-    msg = 'foo'
-    fill_char = '='
-    centered = cu.center_text(msg, fill_char=fill_char)
-    assert msg in centered
-    assert centered.startswith(fill_char)
-    assert centered.endswith(fill_char)
-    letters_in_centered = set(centered)
-    letters_in_msg = set(msg)
-    assert len(letters_in_centered) == len(letters_in_msg) + 1
-
-
-def test_center_text_pad_blank():
-    msg = 'foo'
-    fill_char = ''
+def test_align_text_fill_char_is_tab():
+    text = 'foo'
+    fill_char = '\t'
+    width = 5
+    aligned = cu.align_text(text, fill_char=fill_char, width=width, alignment=cu.TextAlignment.LEFT)
+    assert aligned == text + '  '
+
+def test_align_text_fill_char_is_too_long():
+    text = 'foo'
+    fill_char = 'fill'
+    width = 5
+    with pytest.raises(TypeError):
+        cu.align_text(text, fill_char=fill_char, width=width, alignment=cu.TextAlignment.LEFT)
 
+def test_align_text_fill_char_is_unprintable():
+    text = 'foo'
+    fill_char = '\n'
+    width = 5
     with pytest.raises(ValueError):
-        cu.center_text(msg, fill_char=fill_char)
+        cu.align_text(text, fill_char=fill_char, width=width, alignment=cu.TextAlignment.LEFT)
+
+def test_align_text_has_tabs():
+    text = '\t\tfoo'
+    fill_char = '-'
+    width = 10
+    aligned = cu.align_text(text, fill_char=fill_char, width=width, alignment=cu.TextAlignment.LEFT, tab_width=2)
+    assert aligned == '    ' + 'foo' + '---'
+
+def test_align_text_blank():
+    text = ''
+    fill_char = '-'
+    width = 5
+    aligned = cu.align_text(text, fill_char=fill_char, width=width, alignment=cu.TextAlignment.LEFT)
+    assert aligned == text + fill_char * width
+
+def test_align_text_wider_than_width():
+    text = 'long'
+    fill_char = '-'
+    width = 3
+    aligned = cu.align_text(text, fill_char=fill_char, width=width, alignment=cu.TextAlignment.LEFT)
+    assert aligned == text
+
+def test_align_text_term_width():
+    import shutil
+    from cmd2 import ansi
+    text = 'foo'
+    fill_char = ' '
+
+    term_width = shutil.get_terminal_size().columns
+    expected_fill = (term_width - ansi.ansi_safe_wcswidth(text)) * fill_char
+
+    aligned = cu.align_text(text, fill_char=fill_char, alignment=cu.TextAlignment.LEFT)
+    assert aligned == text + expected_fill
+
+def test_left_text():
+    text = 'foo'
+    fill_char = '-'
+    width = 5
+    aligned = cu.ljustify_text(text, fill_char=fill_char, width=width)
+    assert aligned == text + fill_char + fill_char
+
+def test_left_text_multiline():
+    text = "foo\nshoes"
+    fill_char = '-'
+    width = 7
+    aligned = cu.ljustify_text(text, fill_char=fill_char, width=width)
+    assert aligned == ('foo----\n'
+                       'shoes--')
+
+def test_left_text_asian_fill():
+    """Test fill_char with display width greater than 1"""
+    text = 'foo'
+    fill_char = '苹'
+    width = 5
+    aligned = cu.ljustify_text(text, fill_char=fill_char, width=width)
+    assert aligned == text + fill_char
+
+def test_left_text_asian_fill_needs_padding():
+    """Test when fill_char's display width does not divide evenly into gap"""
+    text = 'foo'
+    fill_char = '苹'
+    width = 6
+    aligned = cu.ljustify_text(text, fill_char=fill_char, width=width)
+    assert aligned == text + fill_char + ' '
+
+def test_center_text():
+    text = 'foo'
+    fill_char = '-'
+    width = 5
+    aligned = cu.center_text(text,fill_char=fill_char,  width=width)
+    assert aligned == fill_char + text + fill_char
+
+def test_center_text_multiline():
+    text = "foo\nshoes"
+    fill_char = '-'
+    width = 7
+    aligned = cu.center_text(text, fill_char=fill_char, width=width)
+    assert aligned == ('--foo--\n'
+                       '-shoes-')
+
+def test_center_text_asian_fill():
+    """Test fill_char with display width greater than 1"""
+    text = 'foo'
+    fill_char = '苹'
+    width = 7
+    aligned = cu.center_text(text, fill_char=fill_char, width=width)
+    assert aligned == fill_char + text + fill_char
+
+def test_center_text_asian_fill_needs_right_padding():
+    """Test when fill_char's display width does not divide evenly into right gap"""
+    text = 'foo'
+    fill_char = '苹'
+    width = 8
+    aligned = cu.center_text(text, fill_char=fill_char, width=width)
+    assert aligned == fill_char + text + fill_char + ' '
+
+def test_center_text_asian_fill_needs_left_and_right_padding():
+    """Test when fill_char's display width does not divide evenly into either gap"""
+    text = 'foo'
+    fill_char = '苹'
+    width = 9
+    aligned = cu.center_text(text, fill_char=fill_char, width=width)
+    assert aligned == fill_char + ' ' + text + fill_char + ' '
+
+def test_right_text():
+    text = 'foo'
+    fill_char = '-'
+    width = 5
+    aligned = cu.rjustify_text(text, fill_char=fill_char,  width=width)
+    assert aligned == fill_char + fill_char + text
+
+def test_right_text_multiline():
+    text = "foo\nshoes"
+    fill_char = '-'
+    width = 7
+    aligned = cu.rjustify_text(text, fill_char=fill_char, width=width)
+    assert aligned == ('----foo\n'
+                       '--shoes')
+
+def test_right_text_asian_fill():
+    """Test fill_char with display width greater than 1"""
+    text = 'foo'
+    fill_char = '苹'
+    width = 5
+    aligned = cu.rjustify_text(text, fill_char=fill_char, width=width)
+    assert aligned == fill_char + text
+
+def test_right_text_asian_fill_needs_padding():
+    """Test when fill_char's display width does not divide evenly into gap"""
+    text = 'foo'
+    fill_char = '苹'
+    width = 6
+    aligned = cu.rjustify_text(text, fill_char=fill_char, width=width)
+    assert aligned == fill_char + ' ' + text