Verify your GraphQL schema changes

GraphQLSchemaTests.cs

using System.Net;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc.Testing;
using Snapshooter.Json;
using Xunit;

namespace MyCompany.MyService
{
    public class GraphQLSchemaTests
        : IClassFixture<WebApplicationFactory<Startup>>
    {
        private readonly WebApplicationFactory<Startup> _factory;
        public GraphQLSchemaTests(WebApplicationFactory<Startup> factory) => _factory = factory;

        [Fact]
        public async Task Is_Approved_GraphQL_Schema()
        {
            // Arrange
            var client = _factory.CreateClient();

            // Act
            var response = await client.GetAsync("/graphql?SDL"); // formerly /graphql/schema on v10

            // Assert
            Assert.Equal(HttpStatusCode.OK, response.StatusCode);
            var schema = await response.Content.ReadAsStringAsync();
            Snapshot.Match(schema);
        }
    }
}