find: Fix unexpectedly accepted empty expression.

[hanbings]

fix: #29

This commit modifies a test function build_top_level_matcher_too_many_brackets outside of my code,
which tests that find -true \( \) \) will return a too many ')' error.

But in GNU find, this instruction will first cause an empty parentheses are not allowed error,
so it is changed to find . -type f \( -name "*.txt" \) \) to maintain compatibility.

[codecov]

Codecov Report

Attention: Patch coverage is 88.88889% with 1 lines in your changes are missing coverage. Please review.

Project coverage is 59.41%. Comparing base (d8e2ce2) to head (0febdac).

Files	Patch %	Lines
src/find/matchers/mod.rs	66.66%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #353      +/-   ##
==========================================
+ Coverage   59.34%   59.41%   +0.06%     
==========================================
  Files          30       30              
  Lines        3822     3831       +9     
  Branches      867      871       +4     
==========================================
+ Hits         2268     2276       +8     
  Misses       1218     1218              
- Partials      336      337       +1     

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[sylvestre]

could you please add a test here: https://github.com/uutils/findutils/blob/main/tests/find_cmd_tests.rs
thanks

[hanbings]

could you please add a test here: https://github.com/uutils/findutils/blob/main/tests/find_cmd_tests.rs thanks

OK, it's included in the latest commit.

[cakebaker]

Thanks!