reported at #52 (comment)

Currently the transmission of variables in the request via puery param does not work either. When I send a request (as defined in the docu https://graphql.org/learn/serving-over-http/), the following error occurs

Field error in object 'graphQLRequest' on field 'variables': rejected value [{
"$content": "123"
}]; codes [typeMismatch.graphQLRequest.variables,typeMismatch.variables,typeMismatch.java.util.Map,typeMismatch]; arguments [org.springframework.context.support.DefaultMessageSourceResolvable: codes [graphQLRequest.variables,variables]; arguments []; default message [variables]]; default message [Failed to convert value of type 'java.lang.String[]' to required type 'java.util.Map'; nested exception is java.lang.IllegalStateException: Cannot convert value of type 'java.lang.String[]' to required type 'java.util.Map': no matching editors or conversion strategy found]]

	@Test
	public void defaultControllerTest_GET_with_variables() throws Exception {
		mockMvc.perform(
				get("/"+apiContext)
						.param("query","query echo($content: String) {echo(content: $content)}")
						.param("variables", "{\n" +
                                "  \"$content\": \"123\"\n" +
                                "}")
						)
				.andExpect(status().isOk())
				.andExpect(content().string(containsString("Hello world")));
	}

reason: Jackson databiner doesn't know how to convert String to Map.