public async Task JsonPatchInputFormatter_ReadsMultipleOperations_Successfully()
        {
            // Arrange
            var logger = GetLogger();
            var formatter = new JsonPatchInputFormatter(logger);
            var content = "[{\"op\": \"add\", \"path\" : \"Customer/Name\", \"value\":\"John\"}," +
                "{\"op\": \"remove\", \"path\" : \"Customer/Name\"}]";
            var contentBytes = Encoding.UTF8.GetBytes(content);

            var modelState = new ModelStateDictionary();
            var httpContext = GetHttpContext(contentBytes);
            var provider = new EmptyModelMetadataProvider();
            var metadata = provider.GetMetadataForType(typeof(JsonPatchDocument<Customer>));
            var context = new InputFormatterContext(
                httpContext,
                modelName: string.Empty,
                modelState: modelState,
                metadata: metadata,
                readerFactory: new TestHttpRequestStreamReaderFactory().CreateReader);

            // Act
            var result = await formatter.ReadAsync(context);

            // Assert
            Assert.False(result.HasError);
            var patchDoc = Assert.IsType<JsonPatchDocument<Customer>>(result.Model);
            Assert.Equal("add", patchDoc.Operations[0].op);
            Assert.Equal("Customer/Name", patchDoc.Operations[0].path);
            Assert.Equal("John", patchDoc.Operations[0].value);
            Assert.Equal("remove", patchDoc.Operations[1].op);
            Assert.Equal("Customer/Name", patchDoc.Operations[1].path);
        }
        public void CanRead_ReturnsTrueOnlyForJsonPatchContentType(string requestContentType, bool expectedCanRead)
        {
            // Arrange
            var logger = GetLogger();
            var formatter = new JsonPatchInputFormatter(logger);
            var content = "[{\"op\": \"add\", \"path\" : \"Customer/Name\", \"value\":\"John\"}]";
            var contentBytes = Encoding.UTF8.GetBytes(content);

            var modelState = new ModelStateDictionary();
            var httpContext = GetHttpContext(contentBytes, contentType: requestContentType);
            var provider = new EmptyModelMetadataProvider();
            var metadata = provider.GetMetadataForType(typeof(JsonPatchDocument<Customer>));
            var formatterContext = new InputFormatterContext(
                httpContext,
                modelName: string.Empty,
                modelState: modelState,
                metadata: metadata,
                readerFactory: new TestHttpRequestStreamReaderFactory().CreateReader);

            // Act
            var result = formatter.CanRead(formatterContext);

            // Assert
            Assert.Equal(expectedCanRead, result);
        }
        public async Task JsonPatchInputFormatter_ReturnsModelStateErrors_InvalidModelType()
        {
            // Arrange
            var exceptionMessage = "Cannot deserialize the current JSON array (e.g. [1,2,3]) into type " +
                $"'{typeof(Customer).FullName}' because the type requires a JSON object ";

            var logger = GetLogger();
            var formatter = new JsonPatchInputFormatter(logger);
            var content = "[{\"op\": \"add\", \"path\" : \"Customer/Name\", \"value\":\"John\"}]";
            var contentBytes = Encoding.UTF8.GetBytes(content);

            var modelState = new ModelStateDictionary();
            var httpContext = GetHttpContext(contentBytes, contentType: "application/json-patch+json");
            var provider = new EmptyModelMetadataProvider();
            var metadata = provider.GetMetadataForType(typeof(Customer));
            var context = new InputFormatterContext(
                httpContext,
                modelName: string.Empty,
                modelState: modelState,
                metadata: metadata,
                readerFactory: new TestHttpRequestStreamReaderFactory().CreateReader);

            // Act
            var result = await formatter.ReadAsync(context);

            // Assert
            Assert.True(result.HasError);
            Assert.Contains(exceptionMessage, modelState[""].Errors[0].Exception.Message);
        }
        public void CanRead_ReturnsFalse_NonJsonPatchContentType(Type modelType)
        {
            // Arrange
            var logger = GetLogger();
            var formatter = new JsonPatchInputFormatter(logger);
            var content = "[{\"op\": \"add\", \"path\" : \"Customer/Name\", \"value\":\"John\"}]";
            var contentBytes = Encoding.UTF8.GetBytes(content);

            var modelState = new ModelStateDictionary();
            var httpContext = GetHttpContext(contentBytes, contentType: "application/json-patch+json");
            var provider = new EmptyModelMetadataProvider();
            var metadata = provider.GetMetadataForType(modelType);
            var formatterContext = new InputFormatterContext(
                httpContext,
                modelName: string.Empty,
                modelState: modelState,
                metadata: metadata,
                readerFactory: new TestHttpRequestStreamReaderFactory().CreateReader);

            // Act
            var result = formatter.CanRead(formatterContext);

            // Assert
            Assert.False(result);
        }