Improve Terminal Output Formatting in pytest-cov

src/pytest_cov/engine.py

@@ -5,6 +5,7 @@
 import functools
 import os
 import random
+import shutil
 import socket
 import sys
 import warnings
@@ -134,15 +135,39 @@ def get_node_desc(platform, version_info):
         return 'platform {}, python {}'.format(platform, '{}.{}.{}-{}-{}'.format(*version_info[:5]))
 
     @staticmethod
-    def sep(stream, s, txt):
+    def get_width():
+        # taken from https://github.com/pytest-dev/pytest/blob/33c7b05a/src/_pytest/_io/terminalwriter.py#L26
+        width, _ = shutil.get_terminal_size(fallback=(80, 24))
+        # The Windows get_terminal_size may be bogus, let's sanify a bit.
+        if width < 40:
+            width = 80
+        return width
+
+    def sep(self, stream, s, txt):
         if hasattr(stream, 'sep'):
             stream.sep(s, txt)
         else:
-            sep_total = max((70 - 2 - len(txt)), 2)
-            sep_len = sep_total // 2
-            sep_extra = sep_total % 2
-            out = f'{s * sep_len} {txt} {s * (sep_len + sep_extra)}\n'
-            stream.write(out)
+            fullwidth = self.get_width()
+            # taken from https://github.com/pytest-dev/pytest/blob/33c7b05a/src/_pytest/_io/terminalwriter.py#L126
+            # The goal is to have the line be as long as possible
+            # under the condition that len(line) <= fullwidth.
+            if sys.platform == 'win32':
+                # If we print in the last column on windows we are on a
+                # new line but there is no way to verify/neutralize this
+                # (we may not know the exact line width).
+                # So let's be defensive to avoid empty lines in the output.
+                fullwidth -= 1
+            N = max((fullwidth - len(txt) - 2) // (2 * len(s)), 1)
+            fill = s * N
+            line = f'{fill} {txt} {fill}'
+            # In some situations there is room for an extra sepchar at the right,
+            # in particular if we consider that with a sepchar like "_ " the
+            # trailing space is not important at the end of the line.
+            if len(line) + len(s.rstrip()) <= fullwidth:
+                line += s.rstrip()
+            # (end of terminalwriter borrowed code)
+            line += '\n\n'
+            stream.write(line)
 
     @_ensure_topdir
     def summary(self, stream):
@@ -155,15 +180,15 @@ def summary(self, stream):
 
         # Output coverage section header.
         if len(self.node_descs) == 1:
-            self.sep(stream, '-', f"coverage: {''.join(self.node_descs)}")
+            self.sep(stream, '_', f"coverage: {''.join(self.node_descs)}")
         else:
-            self.sep(stream, '-', 'coverage')
+            self.sep(stream, '_', 'coverage')
             for node_desc in sorted(self.node_descs):
                 self.sep(stream, ' ', f'{node_desc}')
 
         # Report on any failed workers.
         if self.failed_workers:
-            self.sep(stream, '-', 'coverage: failed workers')
+            self.sep(stream, '_', 'coverage: failed workers')
             stream.write('The following workers failed to return coverage data, ensure that pytest-cov is installed on these workers.\n')
             for node in self.failed_workers:
                 stream.write(f'{node.gateway.id}\n')

src/pytest_cov/plugin.py

@@ -217,6 +217,7 @@ def __init__(self, options, pluginmanager, start=True, no_cov_should_warn=False)
         self._start_path = None
         self._disabled = False
         self.options = options
+        self._wrote_heading = False
 
         is_dist = getattr(options, 'numprocesses', False) or getattr(options, 'distload', False) or getattr(options, 'dist', 'no') != 'no'
         if getattr(options, 'no_cov', False):
@@ -356,9 +357,15 @@ def pytest_runtestloop(self, session):
                 # make sure we get the EXIT_TESTSFAILED exit code
                 compat_session.testsfailed += 1
 
+    def write_heading(self, terminalreporter):
+        if not self._wrote_heading:
+            terminalreporter.write_sep('=', 'tests coverage')
+            self._wrote_heading = True
+
     def pytest_terminal_summary(self, terminalreporter):
         if self._disabled:
             if self.options.no_cov_should_warn:
+                self.write_heading(terminalreporter)
                 message = 'Coverage disabled via --no-cov switch!'
                 terminalreporter.write(f'WARNING: {message}\n', red=True, bold=True)
                 warnings.warn(CovDisabledWarning(message), stacklevel=1)
@@ -372,11 +379,12 @@ def pytest_terminal_summary(self, terminalreporter):
 
         report = self.cov_report.getvalue()
 
-        # Avoid undesirable new lines when output is disabled with "--cov-report=".
         if report:
-            terminalreporter.write('\n' + report + '\n')
+            self.write_heading(terminalreporter)
+            terminalreporter.write(report)
 
         if self.options.cov_fail_under is not None and self.options.cov_fail_under > 0:
+            self.write_heading(terminalreporter)
             failed = self.cov_total < self.options.cov_fail_under
             markup = {'red': True, 'bold': True} if failed else {'green': True}
             message = '{fail}Required test coverage of {required}% {reached}. ' 'Total coverage: {actual:.2f}%\n'.format(