Display node ids and the warnings generated by it

The rationale of using node ids is that users can copy/paste it to run a chosen test

_pytest/terminal.py

@@ -2,6 +2,9 @@
 
 This is a good source for looking at the various reporting hooks.
 """
+import operator
+import itertools
+
 from _pytest.main import EXIT_OK, EXIT_TESTSFAILED, EXIT_INTERRUPTED, \
     EXIT_USAGEERROR, EXIT_NOTESTSCOLLECTED
 import pytest
@@ -28,7 +31,7 @@ def pytest_addoption(parser):
               "--disable-warnings is set")
     group._addoption('--disable-warnings', '--disable-pytest-warnings', default=False,
                      dest='disable_warnings', action='store_true',
-                     help='disable warnings summary, overrides -r w flag')
+                     help='disable warnings summary')
     group._addoption('-l', '--showlocals',
          action="store_true", dest="showlocals", default=False,
          help="show locals in tracebacks (disabled by default).")
@@ -438,16 +441,15 @@ class TerminalReporter(object):
 
     def summary_warnings(self):
         if self.hasopt("w"):
-            warnings = self.stats.get("warnings")
-            if not warnings:
+            all_warnings = self.stats.get("warnings")
+            if not all_warnings:
                 return
-            self.write_sep("=", "warnings summary")
-            for w in warnings:
-                msg = ''
-                if w.fslocation:
-                    msg += str(w.fslocation) + ' '
-                msg += w.message
-                self._tw.line(msg)
+            self.write_sep("=", "warnings summary", yellow=True, bold=False)
+            grouped = itertools.groupby(all_warnings, key=operator.attrgetter('nodeid'))
+            for nodeid, warnings in grouped:
+                self._tw.line(str(nodeid))
+                for w in warnings:
+                    self._tw.line(w.message)
             self._tw.line('-- Docs: http://doc.pytest.org/en/latest/warnings.html')
 
     def summary_passes(self):

_pytest/warnings.py

@@ -63,7 +63,7 @@ def catch_warnings_for_item(item):
         msg = warnings.formatwarning(
             warning.message, warning.category,
             warning.filename, warning.lineno, warning.line)
-        item.config.warn("unused", msg, fslocation=None)
+        item.warn("unused", msg)
 
 
 @pytest.hookimpl(hookwrapper=True)

testing/test_warnings.py

@@ -4,27 +4,48 @@ import pytest
 WARNINGS_SUMMARY_HEADER = 'warnings summary'
 
 @pytest.fixture
-def pyfile_with_warnings(testdir):
-    testdir.makepyfile('''
-        import warnings
-        def test_func():
-            warnings.warn(PendingDeprecationWarning("functionality is pending deprecation"))
-            warnings.warn(DeprecationWarning("functionality is deprecated"))
-    ''')
+def pyfile_with_warnings(testdir, request):
+    """
+    Create a test file which calls a function in a module which generates warnings.
+    """
+    testdir.syspathinsert()
+    test_name = request.function.__name__
+    module_name = test_name.lstrip('test_') + '_module'
+    testdir.makepyfile(**{
+        module_name: '''
+            import warnings
+            def foo():
+                warnings.warn(PendingDeprecationWarning("functionality is pending deprecation"))
+                warnings.warn(DeprecationWarning("functionality is deprecated"))
+                return 1
+        ''',
+        test_name: '''
+            import {module_name}
+            def test_func():
+                assert {module_name}.foo() == 1
+        '''.format(module_name=module_name)
+    })
 
 
 def test_normal_flow(testdir, pyfile_with_warnings):
+    """
+    Check that the warnings section is displayed, containing test node ids followed by
+    all warnings generated by that test node.
+    """
     result = testdir.runpytest()
     result.stdout.fnmatch_lines([
         '*== %s ==*' % WARNINGS_SUMMARY_HEADER,
 
-        '*test_normal_flow.py:3: PendingDeprecationWarning: functionality is pending deprecation',
+        '*test_normal_flow.py::test_func',
+
+        '*normal_flow_module.py:3: PendingDeprecationWarning: functionality is pending deprecation',
         '  warnings.warn(PendingDeprecationWarning("functionality is pending deprecation"))',
 
-        '*test_normal_flow.py:4: DeprecationWarning: functionality is deprecated',
+        '*normal_flow_module.py:4: DeprecationWarning: functionality is deprecated',
         '  warnings.warn(DeprecationWarning("functionality is deprecated"))',
         '* 1 passed, 2 warnings*',
     ])
+    assert result.stdout.str().count('test_normal_flow.py::test_func') == 1
 
 
 def test_setup_teardown_warnings(testdir, pyfile_with_warnings):
@@ -66,7 +87,7 @@ def test_as_errors(testdir, pyfile_with_warnings, method):
     result = testdir.runpytest(*args)
     result.stdout.fnmatch_lines([
         'E       PendingDeprecationWarning: functionality is pending deprecation',
-        'test_as_errors.py:3: PendingDeprecationWarning',
+        'as_errors_module.py:3: PendingDeprecationWarning',
         '* 1 failed in *',
     ])