Feature/drop python27 (#132)

* removing python2.7 support * using `if` `raise` over `assert` * using `format` strings * using `raise` instead of `exit`
boxed · Jul 17, 2019 · 1d39a91 · 1d39a91
1 parent 1898081
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diff --git a/.travis.yml b/.travis.yml
@@ -8,8 +8,6 @@ stages:
 
 before_install:
   - pip install codecov
-
-
 install:
   - pip install .
 script:
@@ -28,9 +26,7 @@ jobs:
       script:
         - flake8 mutmut
     - stage: test
-      python: "2.7"
-    - python: pypy
-    - python: "3.6"
+      python: "3.6"
     - python: "3.7"
       dist: xenial
     - os: windows
@@ -44,8 +40,7 @@ jobs:
       after_success:
         - python -m codecov
     - stage: deploy
-      python:
-        - 3.6
+      python: "3.6"
       before_script: skip
       after_script: skip
       script:

diff --git a/README.rst b/README.rst
@@ -11,13 +11,16 @@ mutmut - python mutation tester
 .. image:: https://codecov.io/gh/boxed/mutmut/branch/master/graph/badge.svg
   :target: https://codecov.io/gh/boxed/mutmut
 
-Mutmut is a mutation testing system for Python 2 and 3, with a strong focus on
-ease of use. If you don't know what mutation testing is try starting with `this article <https://hackernoon.com/mutmut-a-python-mutation-testing-system-9b9639356c78>`_.
+Mutmut is a mutation testing system for Python 3, with a strong focus on ease
+of use. If you don't know what mutation testing is try starting with
+`this article <https://hackernoon.com/mutmut-a-python-mutation-testing-system-9b9639356c78>`_.
 
 Some highlight features:
 
-- Found mutants can be applied on disk with a simple command making it very easy to work with the results
-- Supports all test runners (because mutmut only needs an exit code from the test command)
+- Found mutants can be applied on disk with a simple command making it very
+  easy to work with the results
+- Supports all test runners (because mutmut only needs an exit code from the
+  test command)
 - Extremely small and simple implementation (less than a thousand lines)
 - Battle tested on tri.struct, tri.declarative, tri.form and tri.table
 - Can use coverage data to only do mutation testing on covered lines
@@ -28,21 +31,22 @@ Install and run
 
 You can get started with a simple:
 
-.. code-block:: shell
+.. code-block:: console
 
-   > pip install mutmut
-   > mutmut run
+    pip install mutmut
+    mutmut run
 
-This will by default run pytest on tests in the "tests" or "test" folder and it will try to figure out where the code to mutate lies. Run
+This will by default run pytest on tests in the "tests" or "test" folder and
+it will try to figure out where the code to mutate lies. Run
 
-.. code-block:: shell
+.. code-block:: console
 
     mutmut --help
 
-for the available flags, to use other runners, etc. The recommended way to use mutmut if
-the defaults aren't working for you is to add a block in `setup.cfg`. Then when you
-come back to mutmut weeks later you don't have to figure out the flags again, just run
-`mutmut run` and it works. Like this:
+for the available flags, to use other runners, etc. The recommended way to use
+mutmut if the defaults aren't working for you is to add a block in `setup.cfg`.
+Then when you come back to mutmut weeks later you don't have to figure out the
+flags again, just run `mutmut run` and it works. Like this:
 
 .. code-block:: ini
 
@@ -53,17 +57,20 @@ come back to mutmut weeks later you don't have to figure out the flags again, ju
     tests_dir=tests/
     dict_synonyms=Struct, NamedStruct
 
-You can stop the mutation run at any time and mutmut will restart where you left off. It's
-also smart enough to retest only the surviving mutants when the test suite changes.
+You can stop the mutation run at any time and mutmut will restart where you
+left off. It's also smart enough to retest only the surviving mutants when the
+test suite changes.
 
-To print the results run `mutmut results`. It will give you output in the form of the commands to apply a mutation:
+To print the results run `mutmut results`. It will give you output in the form
+of the commands to apply a mutation:
 
-.. code-block:: shell
+.. code-block:: console
 
     mutmut apply 3
 
-You can just copy paste those lines and run and you'll get the mutant on disk. You should
-REALLY have the file you mutate under source code control and committed before you mutate it!
+You can just copy paste those lines and run and you'll get the mutant on disk.
+You should **REALLY** have the file you mutate under source code control and
+committed before you mutate it!
 
 
 Whitelisting
@@ -75,54 +82,69 @@ You can mark lines like this:
 
     some_code_here()  # pragma: no mutate
 
-to stop mutation on those lines. Some cases we've found where you need to whitelist lines are:
+to stop mutation on those lines. Some cases we've found where you need to
+whitelist lines are:
 
 - The version string on your library. You really shouldn't have a test for this :P
-- Optimizing break instead of continue. The code runs fine when mutating break to continue, but it's slower.
+- Optimizing break instead of continue. The code runs fine when mutating break
+  to continue, but it's slower.
 
 
 Example mutations
 -----------------
 
 - Integer literals are changed by adding 1. So 0 becomes 1, 5 becomes 6, etc.
-- < is changed to <=
+- `<` is changed to `<=`
 - break is changed to continue and vice versa
 
-In general the idea is that the mutations should be as subtle as possible. See `__init__.py` for the full list.
+In general the idea is that the mutations should be as subtle as possible.
+See `__init__.py` for the full list.
 
 
 Workflow
 --------
 
 This section describes how to work with mutmut to enhance your test suite.
 
-1. Run mutmut with `mutmut run`. A full run is preferred but if you're just getting started you can exit in the middle and start working with what you have found so far.
+1. Run mutmut with `mutmut run`. A full run is preferred but if you're just
+   getting started you can exit in the middle and start working with what you
+   have found so far.
 2. Show the mutants with `mutmut results`
-3. Apply a surviving mutant to disk running `mutmut apply 3` (replace 3 with the relevant mutant ID from `mutmut results`)
+3. Apply a surviving mutant to disk running `mutmut apply 3` (replace 3 with
+   the relevant mutant ID from `mutmut results`)
 4. Write a new test that fails
 5. Revert the mutant on disk
 6. Rerun the new test to see that it now passes
 7. Go back to point 2.
 
-Mutmut keeps a result cache in `.mutmut-cache` so if you want to make sure you run a full mutmut run just delete this file.
+Mutmut keeps a result cache in `.mutmut-cache` so if you want to make sure you
+run a full mutmut run just delete this file.
 
 You can also tell mutmut to just check a single mutant:
 
-.. code-block:: shell
+.. code-block:: console
 
-    > mutmut run 3
+    mutmut run 3
 
 
 JUnit XML support
 -----------------
 
-In order to better integrate with CI/CD systems, `mutmut` supports the generation of a JUnit XML report (using https://pypi.org/project/junit-xml/).
-This option is available by calling `mutmut junitxml`. In order to define how to deal with suspicious and untested mutants, you can use `mutmut junitxml --suspicious-policy=ignore --untested-policy=ignore`.
+In order to better integrate with CI/CD systems, `mutmut` supports the
+generation of a JUnit XML report (using https://pypi.org/project/junit-xml/).
+This option is available by calling `mutmut junitxml`. In order to define how
+to deal with suspicious and untested mutants, you can use
+
+.. code-block:: console
+
+    mutmut junitxml --suspicious-policy=ignore --untested-policy=ignore
+
 The possible values for these policies are:
 
 - `ignore`: Do not include the results on the report at all
 - `skipped`: Include the mutant on the report as "skipped"
 - `error`: Include the mutant on the report as "error"
 - `failure`: Include the mutant on the report as "failure"
 
-If a failed mutant is included in the report, then the unified diff of the mutant will also be included for debugging purposes.
+If a failed mutant is included in the report, then the unified diff of the
+mutant will also be included for debugging purposes.
diff --git a/mutmut/__init__.py b/mutmut/__init__.py
@@ -1,9 +1,6 @@
 # -*- coding: utf-8 -*-
 
-from __future__ import unicode_literals
-
 import re
-import sys
 
 from parso import parse
 from parso.python.tree import Name, Number, Keyword
@@ -18,7 +15,7 @@ def __init__(self, line, index, line_number):
         self.line_number = line_number
 
     def __repr__(self):
-        return 'MutationID(line="%s", index=%s, line_number=%s)' % (self.line, self.index, self.line_number)
+        return 'MutationID(line="{}", index={}, line_number={})'.format(self.line, self.index, self.line_number)
 
     def __eq__(self, other):
         return (self.line, self.index, self.line_number) == (other.line, other.index, other.line_number)
@@ -85,11 +82,13 @@ def matches(self, node, pattern=None, skip_child=None):
         check_value = True
         check_children = True
 
-        # Match type based on the name, so _keyword matches all keywords. Special case for _all that matches everything
+        # Match type based on the name, so _keyword matches all keywords.
+        # Special case for _all that matches everything
         if pattern.type == 'name' and pattern.value.startswith('_') and pattern.value[1:] in ('any', node.type):
             check_value = False
 
-        # The advanced case where we've explicitly marked up a node with the accepted types
+        # The advanced case where we've explicitly marked up a node with
+        # the accepted types
         elif id(pattern) in self.marker_type_by_id:
             if self.marker_type_by_id[id(pattern)] in (pattern.type, 'any'):
                 check_value = False
@@ -140,13 +139,6 @@ def matches(self, node, pattern=None, skip_child=None):
 ]
 
 
-if sys.version_info < (3, 0):   # pragma: no cover (python 2 specific)
-    # noinspection PyUnresolvedReferences
-    text_types = (str, unicode)  # noqa: F821
-else:
-    text_types = (str,)
-
-
 UNTESTED = 'untested'
 OK_KILLED = 'ok_killed'
 OK_SUSPICIOUS = 'ok_suspicious'
@@ -475,7 +467,7 @@ def mutate(context):
     try:
         result = parse(context.source, error_recovery=False)
     except Exception:
-        print('Failed to parse %s. Internal error from parso follows.' % context.filename)
+        print('Failed to parse {}. Internal error from parso follows.'.format(context.filename))
         print('----------------------------------')
         raise
     mutate_list_of_nodes(result, context=context)

diff --git a/mutmut/__main__.py b/mutmut/__main__.py
@@ -1,15 +1,14 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
 
-from __future__ import print_function
-
 import fnmatch
 import itertools
 import os
 import shlex
 import subprocess
 import sys
 import traceback
+from configparser import ConfigParser, NoOptionError, NoSectionError
 from functools import wraps
 from io import open
 from os.path import isdir, exists
@@ -29,31 +28,6 @@
 
 spinner = itertools.cycle('⠋⠙⠹⠸⠼⠴⠦⠧⠇⠏')
 
-if sys.version_info < (3, 0):   # pragma: no cover (python 2 specific)
-    # noinspection PyCompatibility,PyUnresolvedReferences
-    from ConfigParser import ConfigParser, NoOptionError, NoSectionError
-    # This little hack is needed to get the click tester working on python 2.7
-    orig_print = print
-
-    def print(x='', **kwargs):
-        # noinspection PyUnresolvedReferences
-        x = x.decode("utf-8")
-        orig_print(x.encode("utf-8"), **kwargs)
-
-    # noinspection PyShadowingBuiltins
-    class TimeoutError(OSError):
-        """Defining TimeoutError for Python 2 compatibility"""
-
-    # noinspection PyShadowingBuiltins
-    class FileNotFoundError(OSError):
-        """Defining FileNotFoundError for Python 2 compatibility"""
-else:
-    # noinspection PyUnresolvedReferences,PyCompatibility
-    from configparser import ConfigParser, NoOptionError, NoSectionError
-
-    # noinspection PyShadowingBuiltins
-    TimeoutError = TimeoutError
-
 
 # decorator
 def config_from_setup_cfg(**defaults):
@@ -190,7 +164,7 @@ def __init__(self, swallow_output, test_command, exclude_callback,
         self.pre_mutation = pre_mutation
 
     def print_progress(self):
-        print_status('%s/%s  🎉 %s  ⏰ %s  🤔 %s  🙁 %s' % (self.progress, self.total, self.killed_mutants, self.surviving_mutants_timeout, self.suspicious_mutants, self.surviving_mutants))
+        print_status('{}/{}  🎉 {}  ⏰ {}  🤔 {}  🙁 {}'.format(self.progress, self.total, self.killed_mutants, self.surviving_mutants_timeout, self.suspicious_mutants, self.surviving_mutants))
 
 
 DEFAULT_TESTS_DIR = 'tests/:test/'
@@ -265,18 +239,18 @@ def main(command, argument, argument2, paths_to_mutate, backup, runner, tests_di
     :rtype: int
     """
     if version:
-        print("mutmut version %s" % __version__)
+        print("mutmut version {}".format(__version__))
         return 0
 
     if use_coverage and use_patch_file:
         raise click.BadArgumentUsage("You can't combine --use-coverage and --use-patch")
 
     valid_commands = ['run', 'results', 'apply', 'show', 'junitxml']
     if command not in valid_commands:
-        raise click.BadArgumentUsage('%s is not a valid command, must be one of %s' % (command, ', '.join(valid_commands)))
+        raise click.BadArgumentUsage('{} is not a valid command, must be one of {}'.format(command, ', '.join(valid_commands)))
 
     if command == 'results' and argument:
-        raise click.BadArgumentUsage('The %s command takes no arguments' % command)
+        raise click.BadArgumentUsage('The {} command takes no arguments'.format(command))
 
     dict_synonyms = [x.strip() for x in dict_synonyms.split(',')]
 
@@ -387,7 +361,7 @@ def _exclude(context):
             return False
 
     if command != 'run':
-        raise click.BadArgumentUsage("Invalid command %s" % command)
+        raise click.BadArgumentUsage("Invalid command {}".format(command))
 
     mutations_by_file = {}
 
@@ -694,7 +668,7 @@ def feedback(line):
     if returncode == 0 or (using_testmon and returncode == 5):
         baseline_time_elapsed = time() - start_time
     else:
-        raise RuntimeError("Tests don't run cleanly without mutations. Test command was: %s\n\nOutput:\n\n%s" % (test_command, '\n'.join(output)))
+        raise RuntimeError("Tests don't run cleanly without mutations. Test command was: {}\n\nOutput:\n\n{}".format(test_command, '\n'.join(output)))
 
     print(' Done')
 
@@ -723,7 +697,7 @@ def add_mutations_by_file(mutations_by_file, filename, exclude, dict_synonyms):
         mutations_by_file[filename] = list_mutations(context)
         register_mutants(mutations_by_file)
     except Exception as e:
-        raise RuntimeError('Failed while creating mutations for %s, for line "%s"' % (context.filename, context.current_source_line), e)
+        raise RuntimeError('Failed while creating mutations for {}, for line "{}"'.format(context.filename, context.current_source_line), e)
 
 
 def python_source_files(path, tests_dirs, paths_to_exclude=None):