support parsing pylint output

This parses pylint output with a simple regexp and counts one failure per
message reported.

This has not been tested yet, but we decided to apply this commit already.

/acked-by @kirr
/reviewed-on nexedi/nxdtest!11

nxdtest/__init__.py

@@ -70,6 +70,7 @@ def loadNXDTestFile(path): # -> TestEnv
     t = TestEnv()
     g = {'TestCase': t.TestCase,    # TODO + all other public TestEnv methods
          'PyTest':   PyTest,
+         'PyLint': PyLint,
          'UnitTest': UnitTest,}
     with open(path, "r") as f:
         src = f.read()
@@ -499,5 +500,26 @@ class UnitTest:
         return status_dict
 
 
+class PyLint:
+
+    @staticmethod
+    def summary(out, err): # -> status_dict
+        test_count = 1
+        error_count = 0
+        if err:
+            test_count = error_count = '?'
+        else:
+            message_re = re.compile(br'^.*:[\d]+:[\d]+: .+: .*')
+            for line in out.splitlines():
+                if message_re.match(line):
+                    error_count += 1
+        return {
+            'test_count': test_count,
+            'error_count': error_count,
+            'failure_count': 0,
+            'skip_count': 0,
+        }
+
+
 if __name__ == '__main__':
     main()

nxdtest/nxdtest_pylint_test.py

+# -*- coding: utf-8 -*-
+# Copyright (C) 2021  Nexedi SA and Contributors.
+#
+# This program is free software: you can Use, Study, Modify and Redistribute
+# it under the terms of the GNU General Public License version 3, or (at your
+# option) any later version, as published by the Free Software Foundation.
+#
+# You can also Link and Combine this program with other software covered by
+# the terms of any of the Free Software licenses or any of the Open Source
+# Initiative approved licenses and Convey the resulting work. Corresponding
+# source of such a combination shall include the source code for all other
+# software used.
+#
+# This program is distributed WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+#
+# See COPYING file for full licensing terms.
+# See https://www.nexedi.com/licensing for rationale and options.
+
+# verify pylint-related functionality
+
+from nxdtest import _test_result_summary, PyLint
+import pytest
+from golang import b
+
+# [] of (name, out, err, summaryok)
+testv = []
+def case1(name, out, err, summaryok): testv.append((name, out, err, summaryok))
+
+
+case1('multiple-messages', b("""\
+************* Module nxdtest
+nxdtest/__init__.py:411:4: E0001: invalid syntax (<unknown>, line 411) (syntax-error)
+************* Module nxdtest.nxdtest_test
+nxdtest/nxdtest_test.py:27:0: E0001: Cannot import 'nxdtest' due to syntax error 'invalid syntax (<unknown>, line 411)' (syntax-error)
+************* Module nxdtest.nxdtest_pylint_test
+nxdtest/nxdtest_pylint_test.py:22:0: E0001: Cannot import 'nxdtest' due to syntax error 'invalid syntax (<unknown>, line 411)' (syntax-error)
+************* Module nxdtest.nxdtest_unittest_test
+nxdtest/nxdtest_unittest_test.py:22:0: E0001: Cannot import 'nxdtest' due to syntax error 'invalid syntax (<unknown>, line 411)' (syntax-error)
+************* Module nxdtest.nxdtest_pytest_test
+nxdtest/nxdtest_pytest_test.py:22:0: E0001: Cannot import 'nxdtest' due to syntax error 'invalid syntax (<unknown>, line 411)' (syntax-error)
+
+------------------------------------------------------------------
+Your code has been rated at 7.16/10 (previous run: 9.85/10, -2.69)
+
+"""),
+b(''),
+'error\ttestname\t1.000s\t# 1t 5e 0f 0s')
+
+
+case1('one-message', b("""\
+************* Module nxdtest
+nxdtest/__init__.py:89:4: E0213: Method should have "self" as first argument (no-self-argument)
+
+------------------------------------------------------------------
+Your code has been rated at 9.85/10 (previous run: 9.69/10, +0.15)
+"""),
+b(''),
+'error\ttestname\t1.000s\t# 1t 1e 0f 0s')
+
+
+case1('no-messages', b("""\
+
+-------------------------------------------------------------------
+Your code has been rated at 10.00/10 (previous run: 7.16/10, +2.84)
+
+"""),
+b(''),
+'ok\ttestname\t1.000s\t# 1t 0e 0f 0s')
+
+
+case1('invocation-error', b(''),
+b('Something went really wrong'),
+'?\ttestname\t1.000s\t# ?t ?e 0f 0s')
+
+
+@pytest.mark.parametrize("name,out,err,summaryok", testv)
+def test_pylint_summary(name, out, err, summaryok):
+    kw = {'duration': 1.0}
+    kw.update(PyLint.summary(out, err))
+    summary = _test_result_summary('testname', kw)
+    assert summary == summaryok