Ensure body is consumed only once

Fixes: #846
Signed-off-by: Mathieu Parent <math.parent@gmail.com>

vcr/request.py

@@ -3,7 +3,7 @@ import warnings
 from io import BytesIO
 from urllib.parse import parse_qsl, urlparse
 
-from .util import CaseInsensitiveDict
+from .util import CaseInsensitiveDict, _is_nonsequence_iterator
 
 log = logging.getLogger(__name__)
 
@@ -17,8 +17,11 @@ class Request:
         self.method = method
         self.uri = uri
         self._was_file = hasattr(body, "read")
+        self._was_iter = _is_nonsequence_iterator(body)
         if self._was_file:
             self.body = body.read()
+        elif self._was_iter:
+            self.body = list(body)
         else:
             self.body = body
         self.headers = headers
@@ -36,7 +39,11 @@ class Request:
 
     @property
     def body(self):
-        return BytesIO(self._body) if self._was_file else self._body
+        if self._was_file:
+            return BytesIO(self._body)
+        if self._was_iter:
+            return iter(self._body)
+        return self._body
 
     @body.setter
     def body(self, value):

vcr/util.py

@@ -89,9 +89,28 @@ def compose(*functions):
     return composed
 
 
+def _is_nonsequence_iterator(obj):
+    return hasattr(obj, "__iter__") and not isinstance(
+        obj,
+        (bytearray, bytes, dict, list, str),
+    )
+
+
 def read_body(request):
     if hasattr(request.body, "read"):
         return request.body.read()
+    if _is_nonsequence_iterator(request.body):
+        body = list(request.body)
+        if body:
+            if isinstance(body[0], str):
+                return "".join(body).encode("utf-8")
+            elif isinstance(body[0], (bytes, bytearray)):
+                return b"".join(body)
+            elif isinstance(body[0], int):
+                return bytes(body)
+            else:
+                raise ValueError(f"Body type {type(body[0])} not supported")
+        return b""
     return request.body