feature of #18

[sunny0826]

• Reference Feature request #18
• add unit test

[codecov]

Codecov Report

Merging #22 (30b0942) into master (917191c) will increase coverage by 0.27%.
The diff coverage is 14.81%.

@@            Coverage Diff            @@
##           master     #22      +/-   ##
=========================================
+ Coverage    8.78%   9.06%   +0.27%     
=========================================
  Files          15      15              
  Lines         785     805      +20     
=========================================
+ Hits           69      73       +4     
- Misses        707     723      +16     
  Partials        9       9              

Flag	Coverage Δ
unittests	9.06% <14.81%> (+0.27%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
cmd/merge.go	0.00% <ø> (ø)
cmd/switch.go	7.40% <14.81%> (+7.40%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 917191c...30b0942. Read the comment docs.

[sunny0826]

LGTM