refetch in useQuery will auto merge the previous variable with current variable

[Zhuyi731]

Describe the bug
refetch in useQuery will auto merge the previous variable with current variable

To Reproduce
Steps to reproduce the behavior:

see the code below

const testGql = gql`
  query lossList($query: String){
  }   
`
const { refetch } = useQuery(testGql, params, options)
refetch({ query:"first time" })    // the first time with variable  query: first time
refetch({})    //  the second time, I don't want to pass any variable to backend, but it will still merge the privious variable into the current varible

** Reason **
it is caused by the code this line. I think this is a bug, sometimes the server do need a empty request variable.

Expected behavior
the second time's request should request with no varibale

Versions
vue: 3.4.21
vue-apollo: 4.0.2
@apollo/client: 3.9.9

[tristandubbeld]

I think this is a feature rather than a bug, I've recently encountered this too. It's a bit hidden but the docs state the following:

If you provide new values for some of your original query's variables but not all of them, refetch uses each omitted variable's original value.

What fixed it for me was explicitly setting the property value to null.

[nickmessing]

@tristandubbeld that is correct, we should probably try to be more explicit in the docs about it.