harf-serde 1.2a1

A library of classes for HAR data using pyserde.

A library of classes for HAR data using pyserde.

The library is focused on providing a F-Algebra for HAR data and associated morphisms but also contains canonical types for basic usages.

F-Algebra classes

There is one generic-ish class for every HAR type and are affixed with F. All nested HAR types have been replaced with type parameters. Some types have no nested HAR types and so have no generic parameters but are included for completeness.

There is one edge case for post data. Since some of the parameters defined in the spec are mutually exclusive there are two classes for post data. PostDataParamF for ParamF based post data, and PostDataTextF for text based post data. There is a union type PostDataF combining the two for type hints but it cannot be constructed.

All of these types are Functory, by providing a nmap function that takes a function for each of the generic parameters. For example, see the ResponseF class below.

class ResponseF(Generic[A, B, C]):
   ...
   statusText: str
   httpVersion: str
   cookies: List[A]
   headers: List[B]
   content: C
   ...

   def nmap(
       self: "ResponseF[A, B, C]",
       f: Func[A, W],
       g: Func[B, X],
       h: Func[C, Y],
   ) -> "ResponseF[W, X, Y]":
       return replace(
           self,  # type: ignore[arg-type]
           cookies=list(map(f, self.cookies)),
           headers=list(map(g, self.headers)),
           content=h(self.content),
       )

Morphisms

Currently there are just 2 helper morphisms. harf_cata is a general catamorphsim, and harf which helps you build an algebra for harf_cata by taking explicit functions for each HAR type.

For example, if you wanted to count the number of times the string "key" is in headers you could do the following

harf(
    default=0,
    header=lambda h: h.count("key"),
    request=lambda r: sum(r.headers),
    response=lambda r: sum(r.headers),
    entry=lambda e: e.request + e.response,
    log=lambda l: sum(l.entries),
)(har_data)

Canonical/Basic types

For simple usages there are also type aliases for the canonical HAR structure. I.E. Response = ResponseF[Cookie, Header, Content]