Several problems when follow/unfollow Sharepoint site via REST API

If you need to implement follow/unfollow site functionality via javascript you most probably will find the following MS article Follow documents, sites, and tags by using the REST service in SharePoint which contains the following example which uses REST API:

$.ajax( {
	url: followingManagerEndpoint + "/isfollowed",
	type: "POST",
	data: JSON.stringify( { 
		"actor": {
			"__metadata": {
				"type":"SP.Social.SocialActorInfo"
			},
			"ActorType":2,
			"ContentUri":siteUrl,
			"Id":null
		} 
	}),
	headers: { 
		"accept":"application/json;odata=verbose",
		"content-type":"application/json;odata=verbose",
		"X-RequestDigest":$("#__REQUESTDIGEST").val()
	},
	success: function (responseData) { 
		...
	},
	error: requestFailed
});

However currently if you will try to run it you will get the following 400 Bad request error:

{"error":{"code":"-1, Microsoft.OData.Core.ODataException","message":"The property '__metadata' does not exist on type 'SP.Social.SocialActorInfo'. Make sure to only use property names that are defined by the type."}}

The problem is with __metadata property of the actor which seems to be outdated nowadays. In order to avoid this error just remove or comment __metadata from actor object.

Another problem is related with odata=verbose specified in Accept header. If you will try to follow site with it API will return the following 406 Not acceptable error:

{"error":{"code":"-1, Microsoft.SharePoint.Client.ClientServiceException","message":"The HTTP header ACCEPT is missing or its value is invalid."}}

In order to resolve it change odata=verbose to odata.metadata=minimal in Accept header. Here is the working code written with Typescript and SPFx:

context.spHttpClient.post(context.pageContext.web.absoluteUrl + "/_api/social.following/follow",
  SPHttpClient.configurations.v1, {
	headers: {
	  'Accept': 'application/json;odata.metadata=minimal',
	  'Content-type': 'application/json;odata=verbose',
	},
	body: JSON.stringify({
	  "actor": {
		  /*"__metadata": {
			  "type": "SP.Social.SocialActorInfo"
		  },*/
		  "ActorType": 2,
		  "ContentUri": site.url,
		  "Id": null
	  }
	})
  });

Hope that it will help someone.