Development and production error messages

When a query in an added field fails, EntityGraphQL helpfully provides a GraphQL response that contains the error. However, the error message sometimes doesn’t contain the message from the inner exception. For example, if Entity Framework Core is confirmed to throw on warnings in OnConfiguring, like this

optionsBuilder.ConfigureWarnings(b => b.Default(WarningBehavior.Throw));

EntityGraphQL doesn’t show the actual error. For example, for a warning about client-side execution being required, the output is just:

{
    "errors": [
        {
            "message": "Field 'customers' - Exception has been thrown by the target of an invocation."
        }
    ]
}

In development (per IWebHostEnvironment), the underlying cause should be shown. Conversely, for security in production, the error should show the same message that an ASP.NET Core API controller shows in production, with the exception message not provided.

[breyed]

One approach would be a property on SchemaProvider:

/// <summary>
/// Gets or sets whether to expose the <see cref="Exception.Message"/> property of exceptions thrown
/// from application code called by EntityGraphQL and caught by EntityGraphQL.
/// If false, the error message "Internal server error" will be used. If null (the default),
/// exception messages are exposed if the ASP.NET Core `IWebHostEnvironment` service
/// is available and is set to `Developmenet`.
/// </summary>
public bool? ExposeExceptions { get; set; }

[lukemurray]

#262 introduces the ability to control this