Support returning through a finally

--HG--
branch : ast-branch

2 files changed, 19 insertions, 4 deletions

diff --git a/coverage/parser.py b/coverage/parser.py
index 44cb1559..d85f0b57 100644
--- a/coverage/parser.py
+++ b/coverage/parser.py
@@ -426,8 +426,6 @@ class AstArcAnalyzer(object):
     # TODO: listcomps hidden in lists: x = [[i for i in range(10)]]
     # TODO: multi-line listcomps
     # TODO: nested function definitions
-    # TODO: multiple `except` clauses
-    # TODO: return->finally
 
     def process_break_exits(self, exits):
         for block in self.blocks():
@@ -467,8 +465,10 @@ class AstArcAnalyzer(object):
 
     def process_return_exits(self, exits):
         for block in self.blocks():
-            # TODO: need a check here for TryBlock
-            if isinstance(block, FunctionBlock):
+            if isinstance(block, TryBlock) and block.final_start:
+                block.return_from.update(exits)
+                break
+            elif isinstance(block, FunctionBlock):
                 # TODO: what if there is no enclosing function?
                 for exit in exits:
                     self.arcs.add((exit, -block.start))
diff --git a/tests/test_arcs.py b/tests/test_arcs.py
index cd3aafff..88442049 100644
--- a/tests/test_arcs.py
+++ b/tests/test_arcs.py
@@ -682,6 +682,21 @@ class ExceptionArcTest(CoverageTest):
             arcz_unpredicted="45 AB",
         )
 
+    def test_return_finally(self):
+        self.check_coverage("""\
+            a = [1]
+            def func():
+                try:
+                    return 10
+                finally:
+                    a.append(6)
+
+            assert func() == 10
+            assert a == [1, 6]
+            """,
+            arcz=".1 12 28 89 9.  .3 34 46 6-2",
+        )
+
 
 class YieldTest(CoverageTest):
     """Arc tests for generators."""