SPFx Web parts - checking user permissions or user is in a group

you can check the current users permissions on the current web or listitem via the pageContect

this.context.pageContext.listItem.permissions

The current web is

this.context.pageContext.web.permissions

but bear in mind that you have no elevated permisions in SPFx, so you cant check for something you may not have and you can only check in the identify of the current user.

If you have based some functionality on whether the uer has access to a storage area then you may just need to run a request against the storage and see if you get bounced.

 see what the this.context.pageContext.web.permissions object gives you and if that can be useful.

an example is below from https://github.com/SharePoint/sp-dev-solutions/blob/master/solutions/ChangeRequests/src/libraries/common/sharepointUtility.tshttps://github.com/SharePoint/sp-dev-solutions/blob/master/solutions/ChangeRequests/src/libraries/common/sharepointUtility.ts

       public static checkCurrentUserIsAbleToManageList(context: IWebPartContext): boolean {
12             let result = false;
13             let currentPermission = context.pageContext.web.permissions;
14             var isAbleToProvision = currentPermission.hasPermission(SPPermission.manageLists) && currentPermission.hasPermission(SPPermission.managePermissions);
15             console.log("Current user permission: { High:" + currentPermission.value.High + ",Low:" + currentPermission.value.Low + "}");
16             console.log("Current user is" + (isAbleToProvision ? " " : "not ") + "able to manage lists and permissions.");
17             return isAbleToProvision;
18         }