fix(expansion): correct length for 1-element arrays

[reubeno]

Among other things, this fixes some issues with completion for strace command lines.

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

Comments suppressed due to low confidence (1)

brush-core/src/expansion.rs:92

• Ensure that the new from_array behavior is covered by tests, especially for single-element arrays.

pub(crate) fn polymorphic_len(&self) -> usize {

[github-actions]

Test Results

    2 files      9 suites   1m 16s ⏱️
  576 tests   576 ✅ 0 💤 0 ❌
1 138 runs  1 138 ✅ 0 💤 0 ❌

Results for commit b7313a5.

♻️ This comment has been updated with latest results.

[github-actions]

Performance Benchmark Report

Benchmark name	Baseline (μs)	Test/PR (μs)	Delta (μs)	Delta %
clone_shell_object	16.34 μs	16.07 μs	-0.26 μs	⚪ Unchanged
eval_arithmetic	0.19 μs	0.19 μs	-0.00 μs	⚪ Unchanged
expand_one_string	1.57 μs	1.57 μs	0.00 μs	⚪ Unchanged
for_loop	32.17 μs	32.27 μs	0.09 μs	⚪ Unchanged
function_call	3.22 μs	3.30 μs	0.08 μs	⚪ Unchanged
instantiate_shell	48.06 μs	47.99 μs	-0.08 μs	⚪ Unchanged
instantiate_shell_with_init_scripts	21239.79 μs	23084.64 μs	1844.85 μs	🟠 +8.69%
parse_bash_completion	1710.79 μs	1701.11 μs	-9.68 μs	⚪ Unchanged
parse_sample_script	2.20 μs	2.18 μs	-0.03 μs	⚪ Unchanged
run_echo_builtin_command	16.02 μs	16.23 μs	0.20 μs	⚪ Unchanged
run_one_external_command	1847.93 μs	1953.35 μs	105.42 μs	🟠 +5.70%

Code Coverage Report: Only Changed Files listed

Package	Base Coverage	New Coverage	Difference
brush-core/src/expansion.rs	🟢 96.1%	🟢 96.14%	🟢 0.04%
brush-core/src/shell.rs	🟢 77.84%	🟢 77.71%	🔴 -0.13%
Overall Coverage	🟢 74.46%	🟢 74.47%	🟢 0.01%

Minimum allowed coverage is 70%, this run produced 74.47%