source_for_file helper with unit tests

--HG--
branch : issue-426

1 files changed, 26 insertions, 1 deletions

diff --git a/tests/test_python.py b/tests/test_python.py
index ee1e1f95..c4e333ef 100644
--- a/tests/test_python.py
+++ b/tests/test_python.py
@@ -5,8 +5,9 @@
 
 import os
 import sys
+from coverage import env
 
-from coverage.python import get_zip_bytes
+from coverage.python import get_zip_bytes, source_for_file
 
 from tests.coveragetest import CoverageTest
 
@@ -28,3 +29,27 @@ class GetZipBytesTest(CoverageTest):
             self.assertIn('All OK', zip_text)
             # Run the code to see that we really got it encoded properly.
             __import__("encoded_"+encoding)
+
+def test_source_for_file(tmpdir):
+    path = tmpdir.join("a.py")
+    src = str(path)
+    assert src == source_for_file(src)
+    assert src == source_for_file(src + 'c')
+    assert src == source_for_file(src + 'o')
+    unknown = src + 'FOO'
+    assert unknown == source_for_file(unknown)
+    #
+    # On windows if a pyw exists, it is an acceptable source
+    #
+    windows = env.WINDOWS
+    env.WINDOWS = True
+    path_windows = tmpdir.ensure("a.pyw")
+    assert str(path_windows) == source_for_file(src + 'c')
+    #
+    # If both pyw and py exist, py is preferred
+    #
+    path.ensure(file=True)
+    assert src == source_for_file(src + 'c')
+    env.WINDOWS = windows
+    jython_src = "a"
+    assert jython_src + ".py" == source_for_file(jython_src + "$py.class")