chore: improve test coverage

[ubogdan]

Describe the PR
Improve Test Coverage

Relation issue
None.

Additional context
Since property.go and schema.go seems to be done i don't see why not have 100% coverage.

[codecov-io]

Codecov Report

Merging #448 into master will increase coverage by 0.75%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #448      +/-   ##
==========================================
+ Coverage   82.62%   83.37%   +0.75%     
==========================================
  Files           7        7              
  Lines        1456     1456              
==========================================
+ Hits         1203     1214      +11     
+ Misses        143      137       -6     
+ Partials      110      105       -5

Impacted Files	Coverage Δ
property.go	100% <0%> (+1.53%)	⬆️
gen/gen.go	78.18% <0%> (+18.18%)	⬆️

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[easonlin404]

LGTM