Choose the doctest output format in case of failure, still work in progress as a few checks fail (related to #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. Implements `#1749`_.
+
 * 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

@@ -18,7 +18,9 @@ def pytest_addoption(parser):
         help="run doctests in all .py modules",
         dest="doctestmodules")
     group.addoption("--doctest-report",
-        type=str, default="UDIFF", choices=_get_report_choices().keys(),
+        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",
@@ -62,7 +64,6 @@ class ReprFailDoctest(TerminalRepr):
 
 
 class DoctestItem(pytest.Item):
-
     def __init__(self, name, parent, runner=None, dtest=None):
         super(DoctestItem, self).__init__(name, parent)
         self.runner = runner
@@ -297,11 +298,11 @@ def _get_allow_bytes_flag():
 def _get_report_choices():
     import doctest
     return dict(
-        UDIFF=doctest.REPORT_UDIFF,
+        udiff=doctest.REPORT_UDIFF,
-        CDIFF=doctest.REPORT_CDIFF,
+        cdiff=doctest.REPORT_CDIFF,
-        NDIFF=doctest.REPORT_NDIFF,
+        ndiff=doctest.REPORT_NDIFF,
-        ONLY_FIRST_FAILURE=doctest.REPORT_ONLY_FIRST_FAILURE,
+        only_first_failure=doctest.REPORT_ONLY_FIRST_FAILURE,
-        NONE=0,
+        none=0,
     )
 
 

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 @@ class TestDoctests:
                                     "--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: