Updating unit tests and docs

Author: kmvanbrunt

CHANGELOG.md

@@ -2,6 +2,9 @@
 * Enhancements
     * Flushing stderr when setting the window title and printing alerts for better responsiveness in cases where
     stderr is not unbuffered.
+    * Added function to truncate a single line to fit within a given display width. `cmd2.utils.truncate_line`
+    supports characters with display widths greater than 1 and ANSI style sequences.
+    * Added line truncation support to `cmd2.utils` text alignment functions.
 
 ## 0.9.23 (January 9, 2020)
 * Bug Fixes

docs/api/utility_functions.rst

@@ -17,6 +17,8 @@ Utility Functions
 
 .. autofunction:: cmd2.utils.align_right
 
+.. autofunction:: cmd2.utils.truncate_line
+
 .. autofunction:: cmd2.utils.strip_quotes
 
 .. autofunction:: cmd2.utils.namedtuple_with_defaults

tests/test_utils.py

@@ -317,6 +317,13 @@ def test_truncate_line_wide_text():
     truncated = cu.truncate_line(line, max_width)
     assert truncated == '苹苹o\N{HORIZONTAL ELLIPSIS}'
 
+def test_truncate_line_split_wide_text():
+    """Test when truncation results in a string which is shorter than max_width"""
+    line = '1苹2苹'
+    max_width = 3
+    truncated = cu.truncate_line(line, max_width)
+    assert truncated == '1\N{HORIZONTAL ELLIPSIS}'
+
 def test_truncate_line_tabs():
     line = 'has\ttab'
     max_width = 9
@@ -379,6 +386,14 @@ def test_align_text_wider_than_width_truncate():
     aligned = cu.align_text(text, cu.TextAlignment.LEFT, fill_char=fill_char, width=width, truncate=True)
     assert aligned == 'long te\N{HORIZONTAL ELLIPSIS}'
 
+def test_align_text_wider_than_width_truncate_add_fill():
+    """Test when truncation results in a string which is shorter than width and align_text adds filler"""
+    text = '1苹2苹'
+    fill_char = '-'
+    width = 3
+    aligned = cu.align_text(text, cu.TextAlignment.LEFT, fill_char=fill_char, width=width, truncate=True)
+    assert aligned == '1\N{HORIZONTAL ELLIPSIS}-'
+
 def test_align_text_has_unprintable():
     text = 'foo\x02'
     fill_char = '-'