Fix heredoc with space not reported as covered (fixes #102)

[sonikaarora]

Fix heredoc coverage for heredocs with spaces

Fixes #102

Problem

When using heredocs with spaces between << and the delimiter (e.g., << EOF), the heredoc content lines were not being marked as covered, even though they were executed.

Example from issue #102:

cat << EOF > test.txt
This is some file content
EOF

In this case, only line 1 was marked as covered, while lines 2-3 (heredoc content and terminator) were reported as uncovered.

Root Cause

The regex pattern in lib/bashcov/lexer.rb (line 44) did not account for optional whitespace between the heredoc operator and delimiter:

/\A[^\n]+<<-?'?(\w+)'?.*$.*\1/m

This pattern matched heredocs without spaces (<<EOF) but failed to match heredocs with spaces (<< EOF).

Solution

Added \s* to allow optional whitespace between <<-? and the delimiter:

/\A[^\n]+<<-?\s*'?(\w+)'?.*$.*\1/m

Testing

Tested with the exact script from issue #102:

#!/usr/bin/env bash

cat << EOF > test.txt
This is some file content
EOF

Test output:

Testing: test.sh (heredoc with space)
Before: [nil, nil, 1, nil, nil]
After:  [nil, nil, 1, 1, 1]

✓ SUCCESS: All 3 heredoc lines covered!

[coderabbitai]

📝 Walkthrough

Walkthrough

The heredoc detection regex in lib/bashcov/lexer.rb was modified to permit optional spaces between the heredoc operator (<<) and the delimiter. The pattern now recognizes heredocs with spacing that were previously unmatched, while maintaining the same capture group behavior.

Changes

Cohort / File(s)	Summary
Heredoc Detection lib/bashcov/lexer.rb	Modified regex pattern to allow optional spaces after heredoc operator by adding \s* after <<-?

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~8 minutes

Poem

🐰 A space here, a space there,
Now heredocs don't cause despair!
The lexer sees them all the same,
Pattern matching—what a game! ✨

🚥 Pre-merge checks | ✅ 4

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title 'Fix heredoc with space not reported as covered (fixes #102)' directly and clearly describes the main change: fixing heredoc detection when spaces are present after the heredoc operator.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.
Merge Conflict Detection	✅ Passed	✅ No merge conflicts detected when merging into master

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✨ Finishing touches

• 📝 Generate docstrings

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment

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[coderabbitai]

🧹 Nitpick comments (1)

lib/bashcov/lexer.rb (1)

44-44: Good fix — consider [ \t]* instead of \s* to avoid matching newlines.

\s* matches newlines, which could theoretically cause a false match if <<- appears at the end of a line (since the delimiter must be on the same line in bash). Using [ \t]* would be more precise:

Suggested tweak

-          /\A[^\n]+<<-?\s*'?(\w+)'?.*$.*\1/m
+          /\A[^\n]+<<-?[ \t]*'?(\w+)'?.*$.*\1/m

Low risk either way — just a minor robustness improvement.

[sonikaarora]

🧹 Nitpick comments (1)

While technically more precise, \s* vs [ \t]* won't impact behavior here since the [^\n]+ prefix already prevents matching across newlines. The heredoc delimiter must be on the same line in valid bash, so real-world scripts won't trigger the edge case. Leaving as-is for now.

[sonikaarora]

@infertux Can you help with the review please

[infertux]

@sonikaarora Did you use AI to create the pull request? The formatting looks suspiciously nice ;)

Either way, it's a valid bug fix so thank you very much. In the future, it would be nice to add a test case to prevent any regressions though.