Doctest report format option (#1749)

AUTHORS

@@ -94,6 +94,7 @@ Punyashloka Biswal
 Quentin Pradet
 Ralf Schmitt
 Raphael Pierzina
+Romain Dorgueil
 Roman Bolshakov
 Ronny Pfannschmidt
 Ross Lawley

CHANGELOG.rst

@@ -70,6 +70,9 @@ time or change existing behaviors in order to make them less surprising/more use
   namespace in which doctests run.
   Thanks `@milliams`_ for the complete PR (`#1428`_).
 
+* New ``--doctest-report`` option available to change the output format of diffs
+  when running (failing) doctests.
+
 * New ``name`` argument to ``pytest.fixture`` decorator which allows a custom name
   for a fixture (to solve the funcarg-shadowing-fixture problem).
   Thanks `@novas0x2a`_ for the complete PR (`#1444`_).

_pytest/doctest.py

@@ -4,7 +4,7 @@
 import traceback
 
 import pytest
-from _pytest._code.code import TerminalRepr, ReprFileLocation, ExceptionInfo
+from _pytest._code.code import ExceptionInfo, ReprFileLocation, TerminalRepr
 from _pytest.fixtures import FixtureRequest
 
 
@@ -17,6 +17,11 @@ def pytest_addoption(parser):
         action="store_true", default=False,
         help="run doctests in all .py modules",
         dest="doctestmodules")
+    group.addoption("--doctest-report",
+        type=str.lower, default="udiff",
+        help="choose another output format for diffs on doctest failure",
+        choices=sorted(_get_report_choices_keys()),
+        dest="doctestreport")
     group.addoption("--doctest-glob",
         action="append", default=[], metavar="pat",
         help="doctests file matching pattern, default: test*.txt",
@@ -59,7 +64,6 @@ def toterminal(self, tw):
 
 
 class DoctestItem(pytest.Item):
-
     def __init__(self, name, parent, runner=None, dtest=None):
         super(DoctestItem, self).__init__(name, parent)
         self.runner = runner
@@ -94,7 +98,7 @@ def repr_failure(self, excinfo):
             message = excinfo.type.__name__
             reprlocation = ReprFileLocation(filename, lineno, message)
             checker = _get_checker()
-            REPORT_UDIFF = doctest.REPORT_UDIFF
+            REPORT_UDIFF = _get_report_choices().get(self.config.getoption("doctestreport"))
             if lineno is not None:
                 lines = doctestfailure.test.docstring.splitlines(False)
                 # add line numbers to the left of the error message
@@ -291,6 +295,18 @@ def _get_allow_bytes_flag():
     return doctest.register_optionflag('ALLOW_BYTES')
 
 
+def _get_report_choices():
+    import doctest
+    return dict(
+        zip(
+            _get_report_choices_keys(),
+            (doctest.REPORT_UDIFF, doctest.REPORT_CDIFF, doctest.REPORT_NDIFF, doctest.REPORT_ONLY_FIRST_FAILURE, 0, )
+        )
+    )
+
+def _get_report_choices_keys():
+    return ('udiff', 'cdiff', 'ndiff', 'only_first_failure', 'none', )
+
 @pytest.fixture(scope='session')
 def doctest_namespace():
     """

doc/en/doctest.rst

@@ -16,7 +16,6 @@ from docstrings in all python modules (including regular
 python test modules)::
 
     pytest --doctest-modules
-
 You can make these changes permanent in your project by
 putting them into a pytest.ini file like this:
 
@@ -102,6 +101,7 @@ itself::
     >>> get_unicode_greeting()  # doctest: +ALLOW_UNICODE
     'Hello'
 
+
 The 'doctest_namespace' fixture
 -------------------------------
 
@@ -130,3 +130,20 @@ which can then be used in your doctests directly::
         10
         """
         pass
+
+
+Output format
+-------------
+
+You can change the diff output format on failure for your doctests
+by using one of standard doctest modules format in options
+(see :data:`python:doctest.REPORT_UDIFF`, :data:`python:doctest.REPORT_CDIFF`,
+:data:`python:doctest.REPORT_NDIFF`, :data:`python:doctest.REPORT_ONLY_FIRST_FAILURE`)::
+
+    pytest --doctest-modules --doctest-report none
+    pytest --doctest-modules --doctest-report udiff
+    pytest --doctest-modules --doctest-report cdiff
+    pytest --doctest-modules --doctest-report ndiff
+    pytest --doctest-modules --doctest-report only_first_failure
+
+

testing/test_doctest.py

@@ -475,6 +475,85 @@ def foo():
                                     "--junit-xml=junit.xml")
         reprec.assertoutcome(failed=1)
 
+    def _run_doctest_report(self, testdir, format):
+        testdir.makepyfile("""
+            def foo():
+                '''
+                >>> foo()
+                   a  b
+                0  1  4
+                1  2  4
+                2  3  6
+                '''
+                print('   a  b\\n'
+                      '0  1  4\\n'
+                      '1  2  5\\n'
+                      '2  3  6')
+            """)
+        return testdir.runpytest("--doctest-modules", "--doctest-report", format)
+
+    def test_doctest_report_udiff(self, testdir, format='udiff'):
+        result = self._run_doctest_report(testdir, format)
+        result.stdout.fnmatch_lines([
+            '     0  1  4',
+            '    -1  2  4',
+            '    +1  2  5',
+            '     2  3  6',
+        ])
+
+    def test_doctest_report_cdiff(self, testdir):
+        result = self._run_doctest_report(testdir, 'cdiff')
+        result.stdout.fnmatch_lines([
+            '         a  b',
+            '      0  1  4',
+            '    ! 1  2  4',
+            '      2  3  6',
+            '    --- 1,4 ----',
+            '         a  b',
+            '      0  1  4',
+            '    ! 1  2  5',
+            '      2  3  6',
+        ])
+
+    def test_doctest_report_ndiff(self, testdir):
+        result = self._run_doctest_report(testdir, 'ndiff')
+        result.stdout.fnmatch_lines([
+            '         a  b',
+            '      0  1  4',
+            '    - 1  2  4',
+            '    ?       ^',
+            '    + 1  2  5',
+            '    ?       ^',
+            '      2  3  6',
+        ])
+
+    def test_doctest_report_none_or_only_first_failure(self, testdir):
+        for format in 'none', 'only_first_failure':
+            result = self._run_doctest_report(testdir, format)
+            result.stdout.fnmatch_lines([
+                'Expected:',
+                '       a  b',
+                '    0  1  4',
+                '    1  2  4',
+                '    2  3  6',
+                'Got:',
+                '       a  b',
+                '    0  1  4',
+                '    1  2  5',
+                '    2  3  6',
+            ])
+
+    def test_doctest_report_case_insensitive(self, testdir):
+        for format in 'udiff', 'UDIFF', 'uDiFf':
+            self.test_doctest_report_udiff(testdir, format)
+
+    def test_doctest_report_invalid(self, testdir):
+        result = self._run_doctest_report(testdir, 'obviously_invalid_format')
+        result.stderr.fnmatch_lines([
+            "*error: argument --doctest-report: invalid choice: 'obviously_invalid_format' (choose from*"
+        ])
+
+
 
 class TestLiterals: