test(options): increase tests coverage

[jakezhu9]

Description (what this PR does / why we need it):

Which issue(s) this PR fixes (resolves / be part of):

Part of #2147

Other special notes for the reviewers:

[daemon365]

lgtm

[codecov-commenter]

Codecov Report

Merging #2183 (50834c2) into main (187c65b) will increase coverage by 2.45%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main    #2183      +/-   ##
==========================================
+ Coverage   82.22%   84.67%   +2.45%     
==========================================
  Files          86       86              
  Lines        3747     3746       -1     
==========================================
+ Hits         3081     3172      +91     
+ Misses        480      408      -72     
+ Partials      186      166      -20     

Impacted Files	Coverage Δ
internal/context/context.go	97.01% <0.00%> (-2.99%)	⬇️
transport/http/context.go	94.04% <0.00%> (+2.38%)	⬆️
transport/http/server.go	82.53% <0.00%> (+5.55%)	⬆️
transport/http/client.go	85.16% <0.00%> (+6.04%)	⬆️
options.go	100.00% <0.00%> (+8.33%)	⬆️
transport/transport.go	100.00% <0.00%> (+9.09%)	⬆️
transport/grpc/resolver/discovery/resolver.go	87.50% <0.00%> (+10.71%)	⬆️
transport/grpc/resolver/direct/builder.go	100.00% <0.00%> (+12.50%)	⬆️
transport/http/binding/encode.go	100.00% <0.00%> (+18.60%)	⬆️
transport/grpc/resolver/discovery/builder.go	100.00% <0.00%> (+21.27%)	⬆️
... and 3 more

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