fix(event_handlers): handle lack of headers when using auto-compression feature (#1325)

Co-authored-by: Heitor Lessa <lessa@amazon.com>

Author: tbuatois

aws_lambda_powertools/utilities/data_classes/common.py

@@ -32,9 +32,12 @@ def get_header_value(
     headers: Dict[str, str], name: str, default_value: Optional[str], case_sensitive: Optional[bool]
 ) -> Optional[str]:
     """Get header value by name"""
+    # If headers is NoneType, return default value
+    if not headers:
+        return default_value
+
     if case_sensitive:
         return headers.get(name, default_value)
-
     name_lower = name.lower()
 
     return next(

tests/functional/event_handler/test_api_gateway.py

@@ -314,6 +314,24 @@ def return_text() -> Response:
     assert result["body"] == expected_value
 
 
+def test_compress_no_accept_encoding_null_headers():
+    # GIVEN a function with compress=True
+    # AND the request has no headers
+    app = ApiGatewayResolver()
+    expected_value = "Foo"
+
+    @app.get("/my/path", compress=True)
+    def return_text() -> Response:
+        return Response(200, content_types.TEXT_PLAIN, expected_value)
+
+    # WHEN calling the event handler
+    result = app({"path": "/my/path", "httpMethod": "GET", "headers": None}, None)
+
+    # THEN don't perform any gzip compression
+    assert result["isBase64Encoded"] is False
+    assert result["body"] == expected_value
+
+
 def test_cache_control_200():
     # GIVEN a function with cache_control set
     app = ApiGatewayResolver()