[MM-29049] Fix remaining errcheck errors in app, api4 and web package (#31307)

Co-authored-by: Claude <noreply@anthropic.com>

server/channels/api4/data_retention.go

@@ -46,7 +46,9 @@ func getGlobalPolicy(c *Context, w http.ResponseWriter, r *http.Request) {
 		c.Err = model.NewAppError("getGlobalPolicy", "api.marshal_error", nil, "", http.StatusInternalServerError).Wrap(err)
 		return
 	}
-	w.Write(js)
+	if _, err := w.Write(js); err != nil {
+		c.Logger.Warn("Error while writing response", mlog.Err(err))
+	}
 }
 
 func getPolicies(c *Context, w http.ResponseWriter, r *http.Request) {
@@ -69,7 +71,9 @@ func getPolicies(c *Context, w http.ResponseWriter, r *http.Request) {
 		c.Err = model.NewAppError("getPolicies", "api.marshal_error", nil, "", http.StatusInternalServerError).Wrap(err)
 		return
 	}
-	w.Write(js)
+	if _, err := w.Write(js); err != nil {
+		c.Logger.Warn("Error while writing response", mlog.Err(err))
+	}
 }
 
 func getPoliciesCount(c *Context, w http.ResponseWriter, r *http.Request) {
@@ -111,7 +115,9 @@ func getPolicy(c *Context, w http.ResponseWriter, r *http.Request) {
 		c.Err = model.NewAppError("getPolicy", "api.marshal_error", nil, "", http.StatusInternalServerError).Wrap(err)
 		return
 	}
-	w.Write(js)
+	if _, err := w.Write(js); err != nil {
+		c.Logger.Warn("Error while writing response", mlog.Err(err))
+	}
 }
 
 func createPolicy(c *Context, w http.ResponseWriter, r *http.Request) {
@@ -144,7 +150,9 @@ func createPolicy(c *Context, w http.ResponseWriter, r *http.Request) {
 	}
 	auditRec.Success()
 	w.WriteHeader(http.StatusCreated)
-	w.Write(js)
+	if _, err := w.Write(js); err != nil {
+		c.Logger.Warn("Error while writing response", mlog.Err(err))
+	}
 }
 
 func patchPolicy(c *Context, w http.ResponseWriter, r *http.Request) {
@@ -180,7 +188,9 @@ func patchPolicy(c *Context, w http.ResponseWriter, r *http.Request) {
 		return
 	}
 	auditRec.Success()
-	w.Write(js)
+	if _, err := w.Write(js); err != nil {
+		c.Logger.Warn("Error while writing response", mlog.Err(err))
+	}
 }
 
 func deletePolicy(c *Context, w http.ResponseWriter, r *http.Request) {
@@ -226,7 +236,9 @@ func getTeamsForPolicy(c *Context, w http.ResponseWriter, r *http.Request) {
 		c.Err = model.NewAppError("Api4.getTeamsForPolicy", "api.marshal_error", nil, "", http.StatusInternalServerError).Wrap(err)
 		return
 	}
-	w.Write(b)
+	if _, err := w.Write(b); err != nil {
+		c.Logger.Warn("Error while writing response", mlog.Err(err))
+	}
 }
 
 func searchTeamsInPolicy(c *Context, w http.ResponseWriter, r *http.Request) {
@@ -258,7 +270,9 @@ func searchTeamsInPolicy(c *Context, w http.ResponseWriter, r *http.Request) {
 		c.Err = model.NewAppError("searchTeamsInPolicy", "api.marshal_error", nil, "", http.StatusInternalServerError).Wrap(err)
 		return
 	}
-	w.Write(js)
+	if _, err := w.Write(js); err != nil {
+		c.Logger.Warn("Error while writing response", mlog.Err(err))
+	}
 }
 
 func addTeamsToPolicy(c *Context, w http.ResponseWriter, r *http.Request) {
@@ -338,7 +352,9 @@ func getChannelsForPolicy(c *Context, w http.ResponseWriter, r *http.Request) {
 		c.Err = model.NewAppError("Api4.getChannelsForPolicy", "api.marshal_error", nil, "", http.StatusInternalServerError).Wrap(err)
 		return
 	}
-	w.Write(b)
+	if _, err := w.Write(b); err != nil {
+		c.Logger.Warn("Error while writing response", mlog.Err(err))
+	}
 }
 
 func searchChannelsInPolicy(c *Context, w http.ResponseWriter, r *http.Request) {
@@ -377,7 +393,9 @@ func searchChannelsInPolicy(c *Context, w http.ResponseWriter, r *http.Request)
 		return
 	}
 
-	w.Write(channelsJSON)
+	if _, err := w.Write(channelsJSON); err != nil {
+		c.Logger.Warn("Error while writing response", mlog.Err(err))
+	}
 }
 
 func addChannelsToPolicy(c *Context, w http.ResponseWriter, r *http.Request) {
@@ -461,7 +479,9 @@ func getTeamPoliciesForUser(c *Context, w http.ResponseWriter, r *http.Request)
 		c.Err = model.NewAppError("getTeamPoliciesForUser", "api.marshal_error", nil, "", http.StatusInternalServerError).Wrap(jsonErr)
 		return
 	}
-	w.Write(js)
+	if _, err := w.Write(js); err != nil {
+		c.Logger.Warn("Error while writing response", mlog.Err(err))
+	}
 }
 
 func getChannelPoliciesForUser(c *Context, w http.ResponseWriter, r *http.Request) {
@@ -489,5 +509,7 @@ func getChannelPoliciesForUser(c *Context, w http.ResponseWriter, r *http.Reques
 		c.Err = model.NewAppError("getChannelPoliciesForUser", "api.marshal_error", nil, "", http.StatusInternalServerError).Wrap(jsonErr)
 		return
 	}
-	w.Write(js)
+	if _, err := w.Write(js); err != nil {
+		c.Logger.Warn("Error while writing response", mlog.Err(err))
+	}
 }