fix: Return empty array if no values found

[AndrewSisley]

Closes #222

PR includes 3 separate fixes, probably easier to review commit by commit.

[codecov]

Codecov Report

Merging #223 (67a1f02) into develop (270fba2) will increase coverage by 0.02%.
The diff coverage is 80.00%.

@@             Coverage Diff             @@
##           develop     #223      +/-   ##
===========================================
+ Coverage    57.90%   57.93%   +0.02%     
===========================================
  Files           99       99              
  Lines         9571     9582      +11     
===========================================
+ Hits          5542     5551       +9     
- Misses        3413     3414       +1     
- Partials       616      617       +1     

Impacted Files	Coverage Δ
db/tests/utils.go	59.36% <75.00%> (+0.59%)	⬆️
query/graphql/planner/planner.go	72.79% <100.00%> (+0.31%)	⬆️

[orpheuslummis]

[]map[string]interface{}{} is the zero value of a slice which is nil. It seems a matter of preference as which to choose, and I'd recommend consistency with the rest.

assertQueryResults wasn't working properly - i.e. not doing the assertion -- for empty values. This fixes it. 👍

[AndrewSisley]

[]map[string]interface{}{} is the zero value of a slice which is nil. It seems a matter of preference as which to choose, and I'd recommend consistency with the rest.

There is some difference as test tests failed before I changed the expected values - might be due to Golang wierd (nil)(type) != nil stuff - looking deeper into the prod code, as the transactional results don't seem to care whether the expected is empty or nil

[AndrewSisley]

Expected to add quick assert, ended up finding a bug in prod and test code... Code should make a little more sense now.

[jsimnz]

LGTM