🔧 Expand default text mimetypes mentioned in #1023

♻️ define "DEFAULT_TEXT_MIMETYPES" and move to utilities.py

zappa/handler.py

@@ -20,11 +20,11 @@
 # so handle both scenarios.
 try:
     from zappa.middleware import ZappaWSGIMiddleware
-    from zappa.utilities import merge_headers, parse_s3_url
+    from zappa.utilities import merge_headers, parse_s3_url, DEFAULT_TEXT_MIMETYPES
     from zappa.wsgi import common_log, create_wsgi_request
 except ImportError:  # pragma: no cover
     from .middleware import ZappaWSGIMiddleware
-    from .utilities import merge_headers, parse_s3_url
+    from .utilities import merge_headers, parse_s3_url, DEFAULT_TEXT_MIMETYPES
     from .wsgi import common_log, create_wsgi_request
 
 
@@ -286,7 +286,7 @@ def _process_response_body(response: Response, settings: ModuleType) -> Tuple[st
         """
         encode_body_as_base64 = False
         if settings.BINARY_SUPPORT:
-            handle_as_text_mimetypes = ("text/", "application/json")
+            handle_as_text_mimetypes = DEFAULT_TEXT_MIMETYPES
             additional_text_mimetypes = getattr(settings, "ADDITIONAL_TEXT_MIMETYPES", None)
             if additional_text_mimetypes:
                 handle_as_text_mimetypes += tuple(additional_text_mimetypes)

zappa/utilities.py

@@ -20,6 +20,19 @@
 # Settings / Packaging
 ##
 
+# mimetypes starting with entries defined here are considered as TEXT when BINARTY_SUPPORT is True.
+# - Additional TEXT mimetypes may be defined with the 'ADDITIONAL_TEXT_MIMETYPES' setting.
+DEFAULT_TEXT_MIMETYPES = (
+    "text/",
+    "application/json",  # RFC 4627
+    "application/javascript",  # RFC 4329
+    "application/ecmascript",  # RFC 4329
+    "application/xml",  # RFC 3023
+    "application/xml-external-parsed-entity",  # RFC 3023
+    "application/xml-dtd",  # RFC 3023
+    "image/svg+xml",  # RFC 3023
+)
+
 
 def copytree(src, dst, metadata=True, symlinks=False, ignore=None):
     """