Issue #20289: cgi.FieldStorage() now supports the context management protocol.

2 files changed, 19 insertions, 6 deletions

diff --git a/Lib/cgi.py b/Lib/cgi.py
index 1ef780c..a55232e 100755
--- a/Lib/cgi.py
+++ b/Lib/cgi.py
@@ -566,6 +566,12 @@ class FieldStorage:
         except AttributeError:
             pass
 
+    def __enter__(self):
+        return self
+
+    def __exit__(self, *args):
+        self.file.close()
+
     def __repr__(self):
         """Return a printable representation."""
         return "FieldStorage(%r, %r, %r)" % (
diff --git a/Lib/test/test_cgi.py b/Lib/test/test_cgi.py
index 86e1f3a..89a6e84 100644
--- a/Lib/test/test_cgi.py
+++ b/Lib/test/test_cgi.py
@@ -1,4 +1,4 @@
-from test.support import run_unittest, check_warnings
+from test.support import check_warnings
 import cgi
 import os
 import sys
@@ -307,6 +307,17 @@ Content-Type: text/plain
                 got = getattr(files[x], k)
                 self.assertEqual(got, exp)
 
+    def test_fieldstorage_as_context_manager(self):
+        fp = BytesIO(b'x' * 10)
+        env = {'REQUEST_METHOD': 'PUT'}
+        with cgi.FieldStorage(fp=fp, environ=env) as fs:
+            content = fs.file.read()
+            self.assertFalse(fs.file.closed)
+        self.assertTrue(fs.file.closed)
+        self.assertEqual(content, 'x' * 10)
+        with self.assertRaisesRegex(ValueError, 'I/O operation on closed file'):
+            fs.file.read()
+
     _qs_result = {
         'key1': 'value1',
         'key2': ['value2x', 'value2y'],
@@ -481,9 +492,5 @@ Content-Transfer-Encoding: binary
 --AaB03x--
 """
 
-
-def test_main():
-    run_unittest(CgiTests)
-
 if __name__ == '__main__':
-    test_main()
+    unittest.main()