fixup! No longer silently ignore errors in parametrize callable ids

fogo · fogo · commit b363f51acf0c · 2017-01-02T12:55:53.000-02:00
diff --git a/CHANGELOG.rst b/CHANGELOG.rst
@@ -8,8 +8,7 @@ New Features
 * Added an ini option ``doctest_encoding`` to specify which encoding to use for doctest files.
   Thanks `@wheerd`_ for the PR (`#2101`_).
 
-* pytest no longer ignores errors when a callable ids raises in a parametrized
-  test. Thanks `@fogo`_ for the PR.
+* pytest now warns when a callable ids raises in a parametrized test. Thanks `@fogo`_ for the PR.
 
 *
 
diff --git a/_pytest/python.py b/_pytest/python.py
@@ -928,7 +928,12 @@ def _find_parametrized_scope(argnames, arg2fixturedefs, indirect):
 
 def _idval(val, argname, idx, idfn, config=None):
     if idfn:
-        s = idfn(val)
+        s = None
+        try:
+            s = idfn(val)
+        except Exception:
+            import warnings
+            warnings.warn("Raised while trying to determine id of parameter %s at position %d" % (argname, idx))
         if s:
             return _escape_strings(s)
 
diff --git a/testing/python/metafunc.py b/testing/python/metafunc.py
@@ -296,20 +296,30 @@ def ids(val):
     @pytest.mark.issue351
     def test_idmaker_idfn_exception(self):
         from _pytest.python import idmaker
+        from _pytest.recwarn import WarningsRecorder
 
         class BadIdsException(Exception):
             pass
 
         def ids(val):
             raise BadIdsException("ids raised")
 
-        with pytest.raises(BadIdsException) as e:
+        rec = WarningsRecorder()
+        with rec:
             idmaker(("a", "b"), [(10.0, IndexError()),
                                           (20, KeyError()),
                                           ("three", [1, 2, 3]),
             ], idfn=ids)
 
-        assert str(e.value) == "ids raised"
+        assert [str(i.message) for i in rec.list] == [
+            "Raised while trying to determine id of parameter a at position 0",
+            "Raised while trying to determine id of parameter b at position 0",
+            "Raised while trying to determine id of parameter a at position 1",
+            "Raised while trying to determine id of parameter b at position 1",
+            "Raised while trying to determine id of parameter a at position 2",
+            "Raised while trying to determine id of parameter b at position 2",
+        ]
+
 
     def test_parametrize_ids_exception(self, testdir):
         """
@@ -328,9 +338,9 @@ def test_foo(arg):
             """)
         result = testdir.runpytest("--collect-only")
         result.stdout.fnmatch_lines([
-            "*ERROR collecting test_parametrize_ids_exception.py*",
-            "test_parametrize_ids_exception.py:*: in ids",
-            "*raise Exception(\"bad ids\")",
+            "<Module 'test_parametrize_ids_exception.py'>",
+            "  <Function 'test_foo[a]'>",
+            "  <Function 'test_foo[b]'>",
         ])
 
     def test_idmaker_with_ids(self):

Original file line number	Diff line number	Diff line change
`@@ -8,8 +8,7 @@ New Features`
`8`	`8`	* Added an ini option ``doctest_encoding`` to specify which encoding to use for doctest files.
`9`	`9`	Thanks `@wheerd`_ for the PR (`#2101`_).
`10`	`10`
`11`		`-* pytest no longer ignores errors when a callable ids raises in a parametrized`
`12`		- test. Thanks `@fogo`_ for the PR.
	`11`	+* pytest now warns when a callable ids raises in a parametrized test. Thanks `@fogo`_ for the PR.
`13`	`12`
`14`	`13`	`*`
`15`	`14`