fix(complete): complete current and parent directories.

[MasahikoSawada]

This PR is to complete '.' (current directory) and '..' (parent directory) correctly.

[github-actions]

Performance Benchmark Report

Benchmark name	Baseline (μs)	Test/PR (μs)	Delta (μs)	Delta %
clone_shell_object	17.48 μs	17.70 μs	0.23 μs	🟠 +1.30%
eval_arithmetic	0.15 μs	0.15 μs	0.00 μs	⚪ Unchanged
expand_one_string	1.53 μs	1.55 μs	0.02 μs	⚪ Unchanged
for_loop	22.23 μs	22.17 μs	-0.06 μs	⚪ Unchanged
function_call	2.20 μs	2.19 μs	-0.01 μs	⚪ Unchanged
instantiate_shell	53.98 μs	53.66 μs	-0.32 μs	🟢 -0.59%
instantiate_shell_with_init_scripts	24169.07 μs	24057.18 μs	-111.89 μs	⚪ Unchanged
parse_bash_completion	1998.11 μs	1994.58 μs	-3.53 μs	⚪ Unchanged
parse_sample_script	1.92 μs	1.91 μs	-0.01 μs	⚪ Unchanged
run_echo_builtin_command	15.39 μs	15.55 μs	0.16 μs	⚪ Unchanged
tokenize_sample_script	3.54 μs	3.49 μs	-0.05 μs	⚪ Unchanged

Code Coverage Report: Only Changed Files listed

Package	Base Coverage	New Coverage	Difference
brush-core/src/completion.rs	🟠 68.15%	🟠 68.18%	🟢 0.03%
brush-core/src/expansion.rs	🟢 94.5%	🟢 94.42%	🔴 -0.08%
Overall Coverage	🟢 76.25%	🟢 76.24%	🔴 -0.01%

Minimum allowed coverage is 70%, this run produced 76.24%

Test Summary: bash-completion test suite

Outcome	Count	Percentage
✅ Pass	1562	74.06
❗️ Error	18	0.85
❌ Fail	175	8.30
⏩ Skip	339	16.07
❎ Expected Fail	13	0.62
✔️ Unexpected Pass	2	0.09
📊 Total	2109	100.00

[reubeno]

Thanks for posting this, @MasahikoSawada! The change looks reasonable and even seems to increase the pass rate on bash-completion tests 😄

The test failure looks like it's coming from the new assertions you've added to completion_tests.rs. I assume you'll look into that?

[reubeno]

Hi @MasahikoSawada -- are you still interested in finishing this up?

We appreciate the contribution and it would be great to get this merged. (I'm assuming it primarily needs a rebase and a look at the failing unit tests?)