asa: rewrite and add tests

[jgarzik]

No description provided.

[Copilot]

Pull request overview

This PR rewrites the asa utility to fix correctness issues and adds comprehensive test coverage. The rewrite simplifies the implementation by processing lines immediately rather than accumulating them in a state machine, resulting in clearer and more maintainable code.

Key changes:

• Removed the AsaState struct and associated complexity
• Implemented direct line-by-line processing with proper POSIX-compliant behavior
• Added 20 comprehensive test cases covering edge cases, POSIX requirements, and FORTRAN-style output

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
text/tests/text-tests.rs	Added asa test module declaration
text/tests/asa/mod.rs	New comprehensive test suite with 20 test cases covering empty input, control characters (' ', '0', '1', '+', '-'), edge cases, and FORTRAN-style reports
text/asa.rs	Complete rewrite: removed AsaState struct, simplified to direct line processing, fixed POSIX compliance for '+' as first character, removed malformed line error, removed unused gettext import

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[Copilot]

The line extraction logic has two issues with multi-byte UTF-8 characters:

1. It uses hardcoded byte index 1 and comparison line_end > 1, assuming the first character is always single-byte ASCII
2. If a multi-byte UTF-8 character is encountered as the control character, raw_line[1..line_end] will panic with a "byte index is not a char boundary" error

While the ASA format typically uses ASCII control characters, the code should handle this gracefully. The fix should:

• Replace 1 with ch.len_utf8() in the slice
• Replace line_end > 1 with line_end > ch.len_utf8()

Example: let line = if line_end > ch.len_utf8() { &raw_line[ch.len_utf8()..line_end] } else { "" };

Suggested change

	let line = if line_end > 1 {
	&raw_line[1..line_end]
	let line = if line_end > ch.len_utf8() {
	&raw_line[ch.len_utf8()..line_end]