Incompatibility with .Net Core 3.1.3, System.Text.JSON and Newtonsoft.JSON

Problem

While attemping to handle a shopify uninstall webhook, I came across this bug.

Error

the json value could not be converted to System.String. Cannot get the value of a token type ‘Number’ as a string

Config

• .Net Core 3.1.3
• ShopifySharp 5.1.0

Step to reproduce

1. Setup an uninstall webhook and a Controller to handle the webhook
2. Install your shopify app
3. Uninstall your shopify app

startup.cs

public void ConfigureServices(IServiceCollection services)
{
       services.AddControllers();
...
}

controller.cs

[HttpPost("uninstall")]
public async Task ExecuteUninstallWebhook([FromBody] Shop shop)
{
        // throws the InvalidOperationException and a 400 BadRequest
}

Hotfix

As bypass you can set NewtonsoftJson as default formatter.

1. Install Microsoft.AspNetCore.Mvc.NewtonsoftJson
2. AddNewtonsoftJson to project. startup.cs

public void ConfigureServices(IServiceCollection services)
{
       services.AddControllers().AddNewtonsoftJson();
       ...
}

However this is setting NewtonsoftJson as default formattor, making the library incompatible with .Net Core 3.0 implementation of System.Text.JSON.

Suggestion

Migrate the library to System.Text.JSON to make it compatible with .Net Core 3.0 +

[nozzlegear]

I agree, it should be added to the documentation. I need to go through the docs and get them updated, they’re currently a little bit out of date in some areas now that we’ve published v5.0.

[clement911]

Yeah, that’s what Stripe.net does. https://github.com/stripe/stripe-dotnet/blob/master/src/Stripe.net/Entities/_base/StripeEntity.cs#L95