Merge pull request #13 from orsinium-labs/body-data

Make Read return Data, add ContentType middleware

Author: orsinium

josh.go

@@ -70,31 +70,31 @@ func SetHeader(r Req, key headers.Header, value string) {
 // Read and parse request body as JSON.
 //
 // Accepts the expected value of "type" field and Req.Body.
-func Read[T any](t string, r io.Reader) (T, error) {
-	// TODO: improve based on this blog post:
-	// https://www.alexedwards.net/blog/how-to-properly-parse-a-json-request-body
+func Read[T any](t string, r io.Reader) (Data[T], error) {
 	if r == nil {
-		return *new(T), errors.New("request body is empty")
+		return Data[T]{}, errors.New("request body is empty")
 	}
 	var v struct {
 		Data *Data[T] `json:"data"`
 	}
+	r = io.LimitReader(r, 1024*1024)
 	decoder := json.NewDecoder(r)
 	decoder.DisallowUnknownFields()
 	err := decoder.Decode(&v)
 	if err != nil {
-		return *new(T), err
+		return Data[T]{}, err
 	}
 	if v.Data == nil {
-		return *new(T), errors.New("data field not found in request body")
+		return Data[T]{}, errors.New("data field not found in request body")
 	}
-	if v.Data.Type != t {
-		return *new(T), fmt.Errorf("unexpected request type: expected %s, got %s", t, v.Data.Type)
+	if t != "" && v.Data.Type != t {
+		return *v.Data, fmt.Errorf("unexpected request type: expected %s, got %s", t, v.Data.Type)
 	}
-	if v.Data.ID != "" {
-		return *new(T), errors.New("requests cannot contain id")
+	err = decoder.Decode(&struct{}{})
+	if !errors.Is(err, io.EOF) {
+		return Data[T]{}, errors.New("request body contains more than one JSON object")
 	}
-	return v.Data.Attributes, nil
+	return *v.Data, nil
 }
 
 // Resp is a response type.

josh_test.go

@@ -62,10 +62,11 @@ func TestUnwrap(t *testing.T) {
 
 func TestRead(t *testing.T) {
 	h := josh.Wrap(func(r josh.Req) josh.Resp {
-		msg, err := josh.Read[string]("foo", r.Body)
+		body, err := josh.Read[string]("foo", r.Body)
 		if err != nil {
 			panic(err)
 		}
+		msg := body.Attributes
 		msg = strings.ToUpper(msg)
 		return josh.Ok(msg)
 	})

middlewares/content_type.go

@@ -0,0 +1,32 @@
+package middlewares
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/orsinium-labs/josh"
+	"github.com/orsinium-labs/josh/statuses"
+)
+
+// Require the request to have a specific Content-Type.
+//
+// If "ct" is an empty string, the "application/vnd.api+json" will be required.
+func ContentType(ct string, h josh.Handler) josh.Handler {
+	if ct == "" {
+		ct = "application/vnd.api+json"
+	}
+	return func(r josh.Req) josh.Resp {
+		act := r.Header.Get("Content-Type")
+		mediaType := strings.ToLower(strings.TrimSpace(strings.Split(act, ";")[0]))
+		if mediaType != ct {
+			return josh.Resp{
+				Status: statuses.UnsupportedMediaType,
+				Errors: []josh.Error{{
+					Title:  "Unsupported Content-Type",
+					Detail: fmt.Sprintf("The request must have %s Content-Type", ct),
+				}},
+			}
+		}
+		return h(r)
+	}
+}