go: encoding/json: eof error of NewDecoder().Decode() should be same with Unmarshal()

Sir I’m using go1.14

var member Member // struct type err := json.NewDecoder(request.Body).Decode(&member); if err != nil{println(err)} // yeah this return eof & I expected value

I support changing it to io.ErrUnexpectedEOF for the following reasons:

• Despite the documentation on ErrUnexpectedEOF, I (and my observation of other parser code) has commonly interpreted that error as indicating that is some number of bytes you could be appended to the string to turn in into a valid input.
• It is generally safer to move from a less distinguishable to a more distinguishable error. While SyntaxError is distinguishable, it is functionally less so than ErrUnexpectedEOF, which only requires a comparison instead of a type assertion.

Any news on this?

Sure, I can fix the tests. Just needed a confirmation on whether to go ahead or not.

@dsnet - I tried changing it to io.ErrUnexpectedEOF and several tests failed -.

--- FAIL: TestUnmarshal (0.00s)
    decode_test.go:1016: #38: checkValid: &errors.errorString{s:"unexpected EOF"}
--- FAIL: TestUnmarshalSyntax (0.00s)
    decode_test.go:1962: expected syntax error for Unmarshal("\"hello"): got *errors.errorString
    decode_test.go:1962: expected syntax error for Unmarshal("[1,2,3"): got *errors.errorString
    decode_test.go:1962: expected syntax error for Unmarshal("{\"key\":1"): got *errors.errorString
    decode_test.go:1962: expected syntax error for Unmarshal("{\"key\":1,"): got *errors.errorString
FAIL
FAIL	encoding/json	1.086s

Whereas, if I do the other way and change to SyntaxError, no tests fail. It seems to me that changing to SyntaxError may actually be less invasive.

But your call. Let me know.