HttpClientExtensions.cs

using System.Net.Http.Headers;
using System.Net.Http.Json;
using System.Text.Json;

namespace Digdir.Domain.Dialogporten.Infrastructure;

public static class HttpClientExtensions
{
    public static async Task<T> GetFromJsonEnsuredAsync<T>(
        this HttpClient client,
        string requestUri,
        Action<HttpRequestHeaders>? configureHeaders = null,
        CancellationToken cancellationToken = default)
    {
        var httpRequestMessage = new HttpRequestMessage(HttpMethod.Get, requestUri);
        configureHeaders?.Invoke(httpRequestMessage.Headers);
        var response = await client.SendAsync(httpRequestMessage, cancellationToken);
        response.EnsureSuccessStatusCode();
        var result = await response.Content.ReadFromJsonAsync<T>(cancellationToken: cancellationToken);
        return result is null
            ? throw new InvalidOperationException($"Failed to deserialize JSON from {requestUri}")
            : result;
    }

    public static async Task<HttpResponseMessage> PostAsJsonEnsuredAsync(
        this HttpClient client,
        string requestUri,
        object content,
        Action<HttpRequestHeaders>? configureHeaders = null,
        Action<HttpContentHeaders>? configureContentHeaders = null,
        JsonSerializerOptions? serializerOptions = null,
        CancellationToken cancellationToken = default)
    {
        var httpRequestMessage = new HttpRequestMessage(HttpMethod.Post, requestUri)
        {
            Content = JsonContent.Create(content, options: serializerOptions)
        };
        configureHeaders?.Invoke(httpRequestMessage.Headers);
        configureContentHeaders?.Invoke(httpRequestMessage.Content.Headers);
        var response = await client.SendAsync(httpRequestMessage, cancellationToken);
        response.EnsureSuccessStatusCode();
        return response;
    }

    public static async Task<T> PostAsJsonEnsuredAsync<T>(
        this HttpClient client,
        string requestUri,
        object content,
        Action<HttpRequestHeaders>? configureHeaders = null,
        Action<HttpContentHeaders>? configureContentHeaders = null,
        JsonSerializerOptions? serializerOptions = null,
        CancellationToken cancellationToken = default)
    {
        var response = await client.PostAsJsonEnsuredAsync(requestUri, content, configureHeaders,
            configureContentHeaders, serializerOptions, cancellationToken);
        var result = await response.Content.ReadFromJsonAsync<T>(cancellationToken: cancellationToken);
        return result is null
            ? throw new InvalidOperationException($"Failed to deserialize JSON to type {typeof(T).FullName} from {requestUri}")
            : result;
    }
}