Raise CollectError if import test module fails

One of the reasons for failing to import the test module is invalid Python
identifiers in the full package path of the test module.

fix #1426

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*",
         ])