Browse Source

http: http-utils added after extraction

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
pull/1842/head
Emmanuel Odeke 7 years ago
parent
commit
d67a621715
No known key found for this signature in database GPG Key ID: 1CA47A292F89DD40
2 changed files with 403 additions and 0 deletions
  1. +153
    -0
      common/http.go
  2. +250
    -0
      common/http_test.go

+ 153
- 0
common/http.go View File

@ -0,0 +1,153 @@
package common
import (
"encoding/json"
"io"
"net/http"
"gopkg.in/go-playground/validator.v9"
"github.com/pkg/errors"
)
type ErrorResponse struct {
Success bool `json:"success,omitempty"`
// Err is the error message if Success is false
Err string `json:"error,omitempty"`
// Code is set if Success is false
Code int `json:"code,omitempty"`
}
// ErrorWithCode makes an ErrorResponse with the
// provided err's Error() content, and status code.
// It panics if err is nil.
func ErrorWithCode(err error, code int) *ErrorResponse {
return &ErrorResponse{
Err: err.Error(),
Code: code,
}
}
// Ensure that ErrorResponse implements error
var _ error = (*ErrorResponse)(nil)
func (er *ErrorResponse) Error() string {
return er.Err
}
// Ensure that ErrorResponse implements httpCoder
var _ httpCoder = (*ErrorResponse)(nil)
func (er *ErrorResponse) HTTPCode() int {
return er.Code
}
var errNilBody = errors.Errorf("expecting a non-nil body")
// FparseJSON unmarshals into save, the body of the provided reader.
// Since it uses json.Unmarshal, save must be of a pointer type
// or compatible with json.Unmarshal.
func FparseJSON(r io.Reader, save interface{}) error {
if r == nil {
return errors.Wrap(errNilBody, "Reader")
}
dec := json.NewDecoder(r)
if err := dec.Decode(save); err != nil {
return errors.Wrap(err, "Decode/Unmarshal")
}
return nil
}
// ParseRequestJSON unmarshals into save, the body of the
// request. It closes the body of the request after parsing.
// Since it uses json.Unmarshal, save must be of a pointer type
// or compatible with json.Unmarshal.
func ParseRequestJSON(r *http.Request, save interface{}) error {
if r == nil || r.Body == nil {
return errNilBody
}
defer r.Body.Close()
return FparseJSON(r.Body, save)
}
// ParseRequestAndValidateJSON unmarshals into save, the body of the
// request and invokes a validator on the saved content. To ensure
// validation, make sure to set tags "validate" on your struct as
// per https://godoc.org/gopkg.in/go-playground/validator.v9.
// It closes the body of the request after parsing.
// Since it uses json.Unmarshal, save must be of a pointer type
// or compatible with json.Unmarshal.
func ParseRequestAndValidateJSON(r *http.Request, save interface{}) error {
if r == nil || r.Body == nil {
return errNilBody
}
defer r.Body.Close()
return FparseAndValidateJSON(r.Body, save)
}
// FparseAndValidateJSON like FparseJSON unmarshals into save,
// the body of the provided reader. However, it invokes the validator
// to check the set validators on your struct fields as per
// per https://godoc.org/gopkg.in/go-playground/validator.v9.
// Since it uses json.Unmarshal, save must be of a pointer type
// or compatible with json.Unmarshal.
func FparseAndValidateJSON(r io.Reader, save interface{}) error {
if err := FparseJSON(r, save); err != nil {
return err
}
return validate(save)
}
var theValidator = validator.New()
func validate(obj interface{}) error {
return errors.Wrap(theValidator.Struct(obj), "Validate")
}
// WriteSuccess JSON marshals the content provided, to an HTTP
// response, setting the provided status code and setting header
// "Content-Type" to "application/json".
func WriteSuccess(w http.ResponseWriter, data interface{}) {
WriteCode(w, data, 200)
}
// WriteCode JSON marshals content, to an HTTP response,
// setting the provided status code, and setting header
// "Content-Type" to "application/json". If JSON marshalling fails
// with an error, WriteCode instead writes out the error invoking
// WriteError.
func WriteCode(w http.ResponseWriter, out interface{}, code int) {
blob, err := json.MarshalIndent(out, "", " ")
if err != nil {
WriteError(w, err)
} else {
w.Header().Set("Content-Type", "application/json")
w.WriteHeader(code)
w.Write(blob)
}
}
type httpCoder interface {
HTTPCode() int
}
// WriteError is a convenience function to write out an
// error to an http.ResponseWriter, to send out an error
// that's structured as JSON i.e the form
// {"error": sss, "code": ddd}
// If err implements the interface HTTPCode() int,
// it will use that status code otherwise, it will
// set code to be http.StatusBadRequest
func WriteError(w http.ResponseWriter, err error) {
code := http.StatusBadRequest
if httpC, ok := err.(httpCoder); ok {
code = httpC.HTTPCode()
}
WriteCode(w, ErrorWithCode(err, code), code)
}

+ 250
- 0
common/http_test.go View File

@ -0,0 +1,250 @@
package common_test
import (
"bytes"
"encoding/json"
"errors"
"io"
"io/ioutil"
"net/http"
"net/http/httptest"
"reflect"
"strings"
"sync"
"testing"
"github.com/stretchr/testify/assert"
"github.com/stretchr/testify/require"
"github.com/tendermint/tmlibs/common"
)
func TestWriteSuccess(t *testing.T) {
w := httptest.NewRecorder()
common.WriteSuccess(w, "foo")
assert.Equal(t, w.Code, 200, "should get a 200")
}
var blankErrResponse = new(common.ErrorResponse)
func TestWriteError(t *testing.T) {
tests := [...]struct {
msg string
code int
}{
0: {
msg: "this is a message",
code: 419,
},
}
for i, tt := range tests {
w := httptest.NewRecorder()
msg := tt.msg
// First check without a defined code, should send back a 400
common.WriteError(w, errors.New(msg))
assert.Equal(t, w.Code, http.StatusBadRequest, "#%d: should get a 400", i)
blob, err := ioutil.ReadAll(w.Body)
if err != nil {
assert.Failf(t, "expecting a successful ioutil.ReadAll", "#%d", i)
continue
}
recv := new(common.ErrorResponse)
if err := json.Unmarshal(blob, recv); err != nil {
assert.Failf(t, "expecting a successful json.Unmarshal", "#%d", i)
continue
}
assert.Equal(t, reflect.DeepEqual(recv, blankErrResponse), false, "expecting a non-blank error response")
// Now test with an error that's .HTTPCode() int conforming
// Reset w
w = httptest.NewRecorder()
common.WriteError(w, common.ErrorWithCode(errors.New("foo"), tt.code))
assert.Equal(t, w.Code, tt.code, "case #%d", i)
}
}
type marshalFailer struct{}
var errFooFailed = errors.New("foo failed here")
func (mf *marshalFailer) MarshalJSON() ([]byte, error) {
return nil, errFooFailed
}
func TestWriteCode(t *testing.T) {
codes := [...]int{
0: http.StatusOK,
1: http.StatusBadRequest,
2: http.StatusUnauthorized,
3: http.StatusInternalServerError,
}
for i, code := range codes {
w := httptest.NewRecorder()
common.WriteCode(w, "foo", code)
assert.Equal(t, w.Code, code, "#%d", i)
// Then for the failed JSON marshaling
w = httptest.NewRecorder()
common.WriteCode(w, &marshalFailer{}, code)
wantCode := http.StatusBadRequest
assert.Equal(t, w.Code, wantCode, "#%d", i)
assert.True(t, strings.Contains(string(w.Body.Bytes()), errFooFailed.Error()),
"#%d: expected %q in the error message", i, errFooFailed)
}
}
type saver struct {
Foo int `json:"foo" validate:"min=10"`
Bar string `json:"bar"`
}
type rcloser struct {
closeOnce sync.Once
body *bytes.Buffer
closeChan chan bool
}
var errAlreadyClosed = errors.New("already closed")
func (rc *rcloser) Close() error {
var err = errAlreadyClosed
rc.closeOnce.Do(func() {
err = nil
rc.closeChan <- true
close(rc.closeChan)
})
return err
}
func (rc *rcloser) Read(b []byte) (int, error) {
return rc.body.Read(b)
}
var _ io.ReadCloser = (*rcloser)(nil)
func makeReq(strBody string) (*http.Request, <-chan bool) {
closeChan := make(chan bool, 1)
buf := new(bytes.Buffer)
buf.Write([]byte(strBody))
req := &http.Request{
Header: make(http.Header),
Body: &rcloser{body: buf, closeChan: closeChan},
}
return req, closeChan
}
func TestParseRequestJSON(t *testing.T) {
tests := [...]struct {
body string
wantErr bool
useNil bool
}{
0: {wantErr: true, body: ``},
1: {body: `{}`},
2: {body: `{"foo": 2}`}, // Not that the validate tags don't matter here since we are just parsing
3: {body: `{"foo": "abcd"}`, wantErr: true},
4: {useNil: true, wantErr: true},
}
for i, tt := range tests {
req, closeChan := makeReq(tt.body)
if tt.useNil {
req.Body = nil
}
sav := new(saver)
err := common.ParseRequestJSON(req, sav)
if tt.wantErr {
assert.NotEqual(t, err, nil, "#%d: want non-nil error", i)
continue
}
assert.Equal(t, err, nil, "#%d: want nil error", i)
wasClosed := <-closeChan
assert.Equal(t, wasClosed, true, "#%d: should have invoked close", i)
}
}
func TestFparseJSON(t *testing.T) {
r1 := strings.NewReader(`{"foo": 1}`)
sav := new(saver)
require.Equal(t, common.FparseJSON(r1, sav), nil, "expecting successful parsing")
r2 := strings.NewReader(`{"bar": "blockchain"}`)
require.Equal(t, common.FparseJSON(r2, sav), nil, "expecting successful parsing")
require.Equal(t, reflect.DeepEqual(sav, &saver{Foo: 1, Bar: "blockchain"}), true, "should have parsed both")
// Now with a nil body
require.NotEqual(t, nil, common.FparseJSON(nil, sav), "expecting a nil error report")
}
func TestFparseAndValidateJSON(t *testing.T) {
r1 := strings.NewReader(`{"foo": 1}`)
sav := new(saver)
require.NotEqual(t, common.FparseAndValidateJSON(r1, sav), nil, "expecting validation to fail")
r1 = strings.NewReader(`{"foo": 100}`)
require.Equal(t, common.FparseJSON(r1, sav), nil, "expecting successful parsing")
r2 := strings.NewReader(`{"bar": "blockchain"}`)
require.Equal(t, common.FparseAndValidateJSON(r2, sav), nil, "expecting successful parsing")
require.Equal(t, reflect.DeepEqual(sav, &saver{Foo: 100, Bar: "blockchain"}), true, "should have parsed both")
// Now with a nil body
require.NotEqual(t, nil, common.FparseJSON(nil, sav), "expecting a nil error report")
}
var blankSaver = new(saver)
func TestParseAndValidateRequestJSON(t *testing.T) {
tests := [...]struct {
body string
wantErr bool
useNil bool
}{
0: {wantErr: true, body: ``},
1: {body: `{}`, wantErr: true}, // Here it should fail since Foo doesn't meet the minimum value
2: {body: `{"foo": 2}`, wantErr: true}, // Here validation should fail
3: {body: `{"foo": "abcd"}`, wantErr: true},
4: {useNil: true, wantErr: true},
5: {body: `{"foo": 100}`}, // Must succeed
}
for i, tt := range tests {
req, closeChan := makeReq(tt.body)
if tt.useNil {
req.Body = nil
}
sav := new(saver)
err := common.ParseRequestAndValidateJSON(req, sav)
if tt.wantErr {
assert.NotEqual(t, err, nil, "#%d: want non-nil error", i)
continue
}
assert.Equal(t, err, nil, "#%d: want nil error", i)
assert.False(t, reflect.DeepEqual(blankSaver, sav), "#%d: expecting a set saver", i)
wasClosed := <-closeChan
assert.Equal(t, wasClosed, true, "#%d: should have invoked close", i)
}
}
func TestErrorWithCode(t *testing.T) {
tests := [...]struct {
code int
err error
}{
0: {code: 500, err: errors.New("funky")},
1: {code: 406, err: errors.New("purist")},
}
for i, tt := range tests {
errRes := common.ErrorWithCode(tt.err, tt.code)
assert.Equal(t, errRes.Error(), tt.err.Error(), "#%d: expecting the error values to be equal", i)
assert.Equal(t, errRes.Code, tt.code, "expecting the same status code", i)
assert.Equal(t, errRes.HTTPCode(), tt.code, "expecting the same status code", i)
}
}

Loading…
Cancel
Save