Found common http utils that were being multiply duplicated across
many libraries and since am moving things in basecoin/unstable to
add for more functionality, it's better to put them in one
place.
Utilities and tests added:
- [X] FparseJSON
- [X] FparseAndValidateJSON
- [X] ParseRequestJSON
- [X] ParseAndValidateRequestJSON
- [X] WriteCode
- [X] WriteError
- [X] WriteSuccess
- [X] ErrorResponse
During review from @ethanfrey, made updates:
* Removed tt.want since it was a distraction/artifact that made
the reviewer think the tests weren't testing for both failed
and passed results.
* Added ErrorWithCode as WithCode is a common options pattern
in Go that could cause confusion:
ErrorWithCode(error, int) ErrorResponse
* Using json.NewDecoder(io.Reader) error instead of
ioutil.ReadAll(io.Reader) to slurp all the bytes.
* Added more test scenarios to achieve 100% coverage of http.go
We use WriteFileAtomic in two places:
```
p2p/addrbook.go
338: err = cmn.WriteFileAtomic(filePath, jsonBytes, 0644)
types/priv_validator.go
162: err = WriteFileAtomic(privVal.filePath, jsonBytes, 0600)
```
and we don't need .bak in any of the above. We save priv_validator every
10ms and addrbook every 2 min.
Anton Kaliaev
Emmanuel Odeke
Ethan Buchman
rigel rozanski