No value at JSON path - unit-testing

Question

How to write mockMVC test for the below JSON which has combination of String and Array.
{
"id":1,
"firstName":"NPA",
"lastName":"TAS",
"mobile":"123454321",
"email":"ABCD#GMAIL.COM",
"accounts":[
{
"id":1,
"balance":"$1000",
"custid":"1",
"accNbr":"12345"
}
]
}
My code:
#Test
public void testJson() throws Exception {
mockMvc = MockMvcBuilders.webAppContextSetup(webApplicationContext).build();
mockMvc.perform(get("/acc/1")
.accept(MediaType.APPLICATION_JSON))
.andExpect(status().isOk())
.andExpect(jsonPath("$.accounts.id", Matchers.is(1)))
.andExpect(jsonPath("$.accounts.balance", Matchers.is("$1000")))
.andExpect(jsonPath("$.accounts.accNbr", Matchers.is("12345")))
.andExpect(jsonPath("$.accounts.custid", Matchers.is("1")))
.andExpect(jsonPath("$.*", Matchers.hasSize(4)));
}
i get the exception
No value at JSON path "$.accounts.id", exception:
Expected to find an object with property ['accounts'] in path $ but found 'net.minidev.json.JSONArray'. This is not a json object according to the JsonProvider: 'com.jayway.jsonpath.spi.json.JsonSmartJsonProvider'.
However, if i try using $.accounts[0].id i get exception
No value at JSON path "$.accounts[0].id", exception:
Expected to find an object with property ['accounts'] in path $ but found 'net.minidev.json.JSONArray'. This is not a json object according to the JsonProvider: 'com.jayway.jsonpath.spi.json.JsonSmartJsonProvider'.

Answer 1

The accounts attribute is an array so this: $.accounts.id would have to use an indexer such as: $.accounts[0].id.
From the docs:
[<number> (, <number>)] Array index or indexes
If you are uncertain about which index to use then you can filter the JSON and assert on the filtered account sub document. For example:
$.accounts[?(#.id == 1)].balance: returns $1000
$.accounts[?(#.accNbr == 12345)].id: returns 1
... etc
Plenty more details in the docs and you can use the use the JsonPath evaluator to play around with this.

Answer 2

As #glytching and I have mentioned, there is an array and it should work with $.accounts[0].id.
If you still encounter a problem, I would try to print the result your console:
MvcResult result = mockMvc.perform(MockMvcRequestBuilders
.get("/acc/1").accept(MediaType.APPLICATION_JSON)).andReturn();
String content = result.getResponse().getContentAsString();