Changelog for Falcon 3.1.0

Summary

This release contains several refinements to request validation and error handling, along with some tweaks to response handling for static and downloadable files.

Due to popular demand, TestClient and ASGIConductor now expose convenience shorthand aliases for the simulate_* methods, i.e., simulate_get() is now also available as get(), etc.

Some important bugs were also fixed to ensure applications properly clean up response streams and do not hang when reading request bodies that are streamed using chunked transfer encoding.

This release also adds support for CPython 3.10 and deprecates CPython 3.6.

Changes to Supported Platforms

  • CPython 3.10 is now fully supported. (#1966)

  • Support for Python 3.6 is now deprecated and will be removed in Falcon 4.0.

  • As with the previous release, Python 3.5 support remains deprecated and will no longer be supported in Falcon 4.0.

New & Improved

  • The jsonschema.validate decorator now raises an instance of MediaValidationError instead of the generic HTTPBadRequest for request media validation failures. Although the default behavior is kept unaltered in a backwards-compatible fashion (as the specialized exception subclasses the generic one), but it can now be easily customized by adding an error handler for the new class. (#1320)

  • Due to popular demand, TestClient and ASGIConductor now expose convenience shorthand aliases for the simulate_* methods, i.e., simulate_get() is now also available as get(), etc. (#1806)

  • The Request.range property now has stricter validation:

    • When parsing a byte-range-spec with a last-byte-pos, it must be greater than or equal to first-byte-pos.

    • When parsing a suffix-byte-range-spec, suffix-length must be positive.

    Static routes now support Range requests. This is useful for streaming media and resumable downloads. (#1858)

  • Added a Response.viewable_as property; this is similar to Response.downloadable_as but with an “inline” disposition type so the response will still be displayed in the browser. (#1951)

  • Added support for passing pathlib.Path objects as directory in the add_static_route() method on all targeted Python versions. (#1962)

  • Static routes now set the Content-Length header indicating a served file’s size (or length of the rendered content range). (#1991)

  • When called with deprecated positional arguments, methods and class initializers (such as falcon.HTTPError) will now emit a user-friendlier warning indicating the fully qualified name of the method in question. (#2010)

Fixed

  • If provided, the close() method of an ASGI resp.stream is now guaranteed to be called even in the case of an exception raised while iterating over the data. (#1943)

  • Previously, files could be left open when serving via an ASGI static route (depending on the underlying GC implementation). This has been fixed so that a file is closed explicitly after rendering the response. (#1963)

  • When a request was streamed using the chunked transfer encoding (with no Content-Length known in advance), iterating over req.stream could hang until the client had disconnected. This bug has been fixed, and iteration now stops upon receiving the last body chunk as expected. (#2024)

Misc

  • The compile_uri_template() utility method has been deprecated and will be removed in Falcon 4.0. This function was only employed in the early versions of the framework, and is expected to have been fully supplanted by the CompiledRouter. In the unlikely case it is still in active use, its source code can be simply copied into an affected application. (#1967)

Contributors to this Release

Many thanks to all the contributors for this release!