Unit tests for useQuery

[jackdclark]

Part of #9

Add test coverage for useQuery

 PASS  test/unit/useQuery.test.js
  useQuery
    ✓ calls useClientRequest with query (22ms)
    ✓ calls useClientRequest with options (2ms)
    ✓ returns initial state from useClientRequest & refetch (2ms)
    ✓ bypasses cache when refetch is called (1ms)
    ✓ sends the query on mount if no data & no error (2ms)
    ✓ does not send the same query on mount if data is already present (2ms)
    ✓ does not send the query on mount if there is an error (1ms)
    ✓ adds query to ssrPromises when in ssrMode if no data & no error (3ms)
    ✓ does not add query to ssrPromises when in ssrMode if there is already data (1ms)
    ✓ does not add query to ssrPromises when in ssrMode if there is an error (1ms)
    ✓ does not add query to ssrPromises when in ssrMode if ssr is overridden in options (2ms)
    ✓ does not send the same query twice (2ms)
    ✓ sends the query again if the variables change (5ms)
    ✓ sends another query if the query changes (2ms)

[Joezo]

Tests look good 👍

[bmullan91]

Looking good - a couple of things missing:

1. Testing the refetch function re-calls fetchData passing skipCache=true Sorry, you do have that test, my bad.
2. Is it possible to verify the second argument to the useEffect [query, JSON.stringify(opts.variables)] i.e. change the variables causes it to be re-called

[jackdclark]

@Joezo @bmullan91 thanks for the reviews. I've added the following three tests to cover the useEffect conditional firing

    ✓ does not send the same query twice (2ms)
    ✓ sends the query again if the variables change (2ms)
    ✓ sends another query if the query changes (2ms)

[Joezo]

This looks even better now 👍 🥇

[bmullan91]

LGTM - nice work @jackdclark 😎