Add `Accept` header negotiation to relevant API endpoints (#337)

* start centralizing negotiation logic for API

* swagger document nodeinfo endpoint

* go fmt

* document negotiate function

* use content negotiation

* tidy up negotiation logic

* negotiate content throughout client api

* swagger

* remove attachment on Content

* add accept header to test requests

2 files changed, 14 insertions, 1 deletions

diff --git a/internal/api/client/instance/instanceget.go b/internal/api/client/instance/instanceget.go
index f2f496cb5..4f9afdb38 100644
--- a/internal/api/client/instance/instanceget.go
+++ b/internal/api/client/instance/instanceget.go
@@ -5,6 +5,7 @@ import (
 
 	"github.com/sirupsen/logrus"
 	"github.com/spf13/viper"
+	"github.com/superseriousbusiness/gotosocial/internal/api"
 	"github.com/superseriousbusiness/gotosocial/internal/config"
 
 	"github.com/gin-gonic/gin"
@@ -35,6 +36,11 @@ import (
 func (m *Module) InstanceInformationGETHandler(c *gin.Context) {
 	l := logrus.WithField("func", "InstanceInformationGETHandler")
 
+	if _, err := api.NegotiateAccept(c, api.JSONAcceptHeaders...); err != nil {
+		c.JSON(http.StatusNotAcceptable, gin.H{"error": err.Error()})
+		return
+	}
+
 	host := viper.GetString(config.Keys.Host)
 
 	instance, err := m.processor.InstanceGet(c.Request.Context(), host)
diff --git a/internal/api/client/instance/instancepatch.go b/internal/api/client/instance/instancepatch.go
index 50923dd90..e0200cb0f 100644
--- a/internal/api/client/instance/instancepatch.go
+++ b/internal/api/client/instance/instancepatch.go
@@ -1,10 +1,12 @@
 package instance
 
 import (
-	"github.com/sirupsen/logrus"
 	"net/http"
 
+	"github.com/sirupsen/logrus"
+
 	"github.com/gin-gonic/gin"
+	"github.com/superseriousbusiness/gotosocial/internal/api"
 	"github.com/superseriousbusiness/gotosocial/internal/api/model"
 	"github.com/superseriousbusiness/gotosocial/internal/oauth"
 )
@@ -93,6 +95,11 @@ func (m *Module) InstanceUpdatePATCHHandler(c *gin.Context) {
 		return
 	}
 
+	if _, err := api.NegotiateAccept(c, api.JSONAcceptHeaders...); err != nil {
+		c.JSON(http.StatusNotAcceptable, gin.H{"error": err.Error()})
+		return
+	}
+
 	// only admins can update instance settings
 	if !authed.User.Admin {
 		l.Debug("user is not an admin so cannot update instance settings")