Add an explicit test for weird module docstring behavior.

2 files changed, 26 insertions, 1 deletions

diff --git a/CHANGES.rst b/CHANGES.rst
index 9556bf0e..bc44710f 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -8,7 +8,9 @@ Change history for Coverage.py
 Unreleased
 ----------
 
-(nothing yet)
+- Support for Python 3.7.  In some cases, class and module docstrings are no
+  longer counted in statement totals, which could slightly change your total
+  results.
 
 
 .. _changes_441:
diff --git a/tests/test_coverage.py b/tests/test_coverage.py
index fae85bc6..45abb2be 100644
--- a/tests/test_coverage.py
+++ b/tests/test_coverage.py
@@ -574,6 +574,29 @@ class SimpleStatementTest(CoverageTest):
             [2, 3]
         )
 
+    def test_module_docstring(self):
+        self.check_coverage("""\
+            '''I am a module docstring.'''
+            a = 2
+            b = 3
+            """,
+            [2, 3]
+        )
+        if env.PYVERSION < (3, 7):
+            # Before 3.7, module docstrings were included in the lnotab table,
+            # unless they were the first line in the file?
+            lines = [2, 3, 4]
+        else:
+            lines = [3, 4]
+        self.check_coverage("""\
+            # Start with a comment, because it changes the behavior(!?)
+            '''I am a module docstring.'''
+            a = 3
+            b = 4
+            """,
+            lines
+        )
+
 
 class CompoundStatementTest(CoverageTest):
     """Testing coverage of multi-line compound statements."""