Warn when a template lacks the guard lines past ARGBASH_GO

[gdevenyi]

Related to #205

The user code past ARGBASH_GO has to be enclosed in the # [ <-- needed because of Argbash and # ] <-- needed because of Argbash lines, otherwise m4 strips square brackets from it (for example "${_arg_leftovers[@]}" becomes "${_arg_leftovers@}", which is the symptom reported in #205) and the script gets corrupted silently.

argbash now prints a warning that names the guard lines when it generates a bash or POSIX script (without --strip) from a template that has ARGBASH_GO/ARGBASH_PREPARE but no guard line after it. Generation itself is unchanged.

New regression test test-missing-guards checks that the warning is printed for such a template and not printed for a regular one nor with --strip.

🤖 Generated with Claude Code

https://claude.ai/code/session_017DxhC3HmTM7TQUzkBZnyH2

[Copilot]

🟡 Changes recommended

Guard matching, macro-boundary handling, and POSIX test coverage remain unresolved.

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Pull request overview

Adds warnings when templates lack required Argbash guard lines, with regression coverage and synchronized generator updates.

Changes:

• Adds guard detection and warnings.
• Adds missing-guard fixture and regression tests.
• Updates the generated executable and changelog.

File summaries

File	Description
tests/regressiontests/Makefile	Registers the regression test.
tests/regressiontests/make/tests/tests-base.m4	Defines warning assertions.
tests/regressiontests/gen-test-missing-guards.m4	Provides the malformed template fixture.
src/argbash.m4	Implements missing-guard warning logic.
ChangeLog	Documents the bug fix.
bin/argbash	Mirrors the generator changes.

Review details

Suppressed comments (3)

src/argbash.m4:209

• The detector also matches ARGBASH_PREPARE, but this warning names only ARGBASH_GO and says the code is past ARGBASH_GO. For a DIY template using only ARGBASH_PREPARE, the diagnostic points at a marker that is not present and is misleading about the affected section.

		"Warning: The ARGBASH_GO line is not followed by the '# [ <-- needed because of Argbash' guard line (with the matching '# ] <-- needed because of Argbash' line at the end of the file)." \
		"Square brackets in the code past ARGBASH_GO will be stripped, and the script can't be regenerated correctly. See the 'Template layout' section of the documentation." >&2

src/argbash.m4:203

• Because this expression is not bounded after GO|PREPARE, it also classifies names such as the existing # ARGBASH_GOO typo (tests/regressiontests/gen-test-misspelled.m4:6) as action macros. That produces a misleading missing-guards warning for an input with no action macro; require a token boundary while still accepting the supported (), [ and end-of-line forms.

		/^#[[:space:]]*ARGBASH_(GO|PREPARE)/ { seen_go = 1 }

tests/regressiontests/make/tests/tests-base.m4:352

• The implementation explicitly supports both bash and POSIX script types via the *script check, but this regression only invokes the default bash type. Add equivalent --type posix-script assertions (at least the warning and --strip suppression) so the advertised POSIX path is covered; this suite already has dedicated POSIX tests.

ADD_TEST_BASH([test-missing-guards], [[
	$(ARGBASH_EXEC) $< -o - 2>&1 > /dev/null | grep -q 'needed because of Argbash'
	$(ARGBASH_EXEC) $< --strip user-content -o - 2>&1 > /dev/null | $(REVERSE) grep -q 'needed because of Argbash'
	$(ARGBASH_EXEC) $(TESTDIR)/test-simple.m4 -o - 2>&1 > /dev/null | $(REVERSE) grep -q 'needed because of Argbash'
]], [$(TESTDIR)/test-simple.m4], [$(TESTDIR)/gen-test-missing-guards.m4])

• Files reviewed: 5/6 changed files
• Comments generated: 1
• Review effort level: Lite

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[gdevenyi]

A template with the opening guard but without the closing one does not pass silently: the unmatched quote makes autom4te fail with "end of file in string", and argbash reports the unmatched square bracket and aborts. The warning is meant for the case that is silent (no opening guard at all), so I am leaving the detector as it is.

[gdevenyi]

Addressed the suppressed remarks as well: the detector requires a token boundary after ARGBASH_GO/ARGBASH_PREPARE (so the ARGBASH_GOO typo template no longer triggers it), the message mentions ARGBASH_PREPARE, and the test also covers --type posix-script and the misspelled-macro template.