Raise CollectError if import test module fails

CHANGELOG.rst

@@ -39,7 +39,9 @@
   parametrize.
   Thanks `@palaviv`_ for the complete PR (`#1474`_).
 
-*
+* Fix `#1426`_ Make ImportError during collection more explicit by reminding
+  the user to check the name of the test module/package(s).
+  Thanks `@omarkohl`_ for the complete PR (`#1520`_).
 
 .. _@milliams: https://github.com/milliams
 .. _@novas0x2a: https://github.com/novas0x2a
@@ -49,6 +51,7 @@
 .. _@palaviv: https://github.com/palaviv
 .. _@omarkohl: https://github.com/omarkohl
 
+.. _#1426: https://github.com/pytest-dev/pytest/issues/1426
 .. _#1428: https://github.com/pytest-dev/pytest/pull/1428
 .. _#1444: https://github.com/pytest-dev/pytest/pull/1444
 .. _#1441: https://github.com/pytest-dev/pytest/pull/1441
@@ -57,6 +60,7 @@
 .. _#1468: https://github.com/pytest-dev/pytest/pull/1468
 .. _#1474: https://github.com/pytest-dev/pytest/pull/1474
 .. _#1502: https://github.com/pytest-dev/pytest/pull/1502
+.. _#1520: https://github.com/pytest-dev/pytest/pull/1520
 .. _#372: https://github.com/pytest-dev/pytest/issues/372
 
 2.9.2.dev1

_pytest/python.py

@@ -636,6 +636,14 @@ def _importtestmodule(self):
                 "unique basename for your test file modules"
                  % e.args
             )
+        except ImportError:
+            exc_class, exc, _ = sys.exc_info()
+            raise self.CollectError(
+                "ImportError while importing test module '%s'.\n"
+                "Original error message:\n'%s'\n"
+                "Make sure your test modules/packages have valid Python names."
+                % (self.fspath, exc or exc_class)
+            )
         #print "imported test module", mod
         self.config.pluginmanager.consider_module(mod)
         return mod

testing/acceptance_test.py

@@ -117,7 +117,8 @@ def test_this():
         result = testdir.runpytest(p)
         result.stdout.fnmatch_lines([
             #XXX on jython this fails:  ">   import import_fails",
-            "E   ImportError: No module named *does_not_work*",
+            "ImportError while importing test module*",
+            "'No module named *does_not_work*",
         ])
         assert result.ret == 1
 

testing/python/collect.py

@@ -5,14 +5,16 @@
 import _pytest._code
 import py
 import pytest
-from _pytest.main import EXIT_NOTESTSCOLLECTED
+from _pytest.main import (
+    Collector,
+    EXIT_NOTESTSCOLLECTED
+)
 
 
 class TestModule:
     def test_failing_import(self, testdir):
         modcol = testdir.getmodulecol("import alksdjalskdjalkjals")
-        pytest.raises(ImportError, modcol.collect)
-        pytest.raises(ImportError, modcol.collect)
+        pytest.raises(Collector.CollectError, modcol.collect)
 
     def test_import_duplicate(self, testdir):
         a = testdir.mkdir("a")
@@ -60,6 +62,16 @@ def test_module_considers_pluginmanager_at_import(self, testdir):
         modcol = testdir.getmodulecol("pytest_plugins='xasdlkj',")
         pytest.raises(ImportError, lambda: modcol.obj)
 
+    def test_invalid_test_module_name(self, testdir):
+        a = testdir.mkdir('a')
+        a.ensure('test_one.part1.py')
+        result = testdir.runpytest("-rw")
+        result.stdout.fnmatch_lines([
+            "ImportError while importing test module*test_one.part1*",
+            "Make sure your test modules/packages have valid Python names.",
+        ])
+
+
 class TestClass:
     def test_class_with_init_warning(self, testdir):
         testdir.makepyfile("""

testing/test_collection.py

@@ -176,7 +176,8 @@ def test_collection_error(self, testdir):
         assert "__import__" not in result.stdout.str(), "too long traceback"
         result.stdout.fnmatch_lines([
             "*ERROR collecting*",
-            "*mport*not_exists*"
+            "ImportError while importing test module*",
+            "'No module named *not_exists*",
         ])
 
     def test_custom_repr_failure(self, testdir):

testing/test_session.py

@@ -42,7 +42,7 @@ def test_this():
         reprec = testdir.inline_run(tfile)
         l = reprec.getfailedcollections()
         assert len(l) == 1
-        out = l[0].longrepr.reprcrash.message
+        out = str(l[0].longrepr)
         assert out.find('does_not_work') != -1
 
     def test_raises_output(self, testdir):

testing/test_terminal.py

@@ -276,8 +276,8 @@ def test_collectonly_error(self, testdir):
         assert result.ret == 1
         result.stdout.fnmatch_lines(_pytest._code.Source("""
             *ERROR*
-            *import Errlk*
             *ImportError*
+            *No module named *Errlk*
             *1 error*
         """).strip())
 
@@ -665,8 +665,8 @@ def test_collect_fail(self, testdir, option):
         testdir.makepyfile("import xyz\n")
         result = testdir.runpytest(*option.args)
         result.stdout.fnmatch_lines([
-            "?   import xyz",
-            "E   ImportError: No module named *xyz*",
+            "ImportError while importing*",
+            "'No module named *xyz*",
             "*1 error*",
         ])