fix: resolve the error that value is not an array

[binyellow]

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[codecov]

Codecov Report

Merging #221 (107d528) into master (72da52c) will not change coverage.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master     #221   +/-   ##
=======================================
  Coverage   99.72%   99.72%           
=======================================
  Files           9        9           
  Lines         360      360           
  Branches       92       91    -1     
=======================================
  Hits          359      359           
  Misses          1        1           

Impacted Files	Coverage Δ
src/util.ts	100.00% <100.00%> (ø)

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[afc163]

Could you add a test case?

[afc163]