Optimize dist-archive by preventing descent into ignored directories

[Copilot]

Performance Optimization Complete ✅

• Create a RecursiveFilterIterator class to filter out ignored directories before iteration
• Update get_file_list() to use the filter iterator to prevent descending into ignored directories
• Manual testing confirms ignored directories are no longer scanned
• Add Behat test to verify ignored directories are not scanned
• Fix filter to properly handle both zip and targz formats
• Handle complex gitignore patterns with negations correctly
• All distignore tests pass (27/27 scenarios)
• Address code review feedback (path manipulation, portability, comments)
• All static analysis checks pass (lint, phpcs, phpstan)
• Security review complete (CodeQL)
• Optimize to avoid duplicate isPathIgnored() calls with caching
• Refactor filtering into iterator's accept() method for profound optimization
• Add comprehensive PHPUnit tests for Distignore_Filter_Iterator class

Summary

This PR fixes a critical performance issue where RecursiveIteratorIterator was scanning ALL files in ignored directories before filtering them out. For projects with large node_modules directories (30,000+ files), this made the command nearly unusable.

Solution: Introduced a RecursiveFilterIterator that filters ignored files directly in the accept() method, preventing them from being yielded to the foreach loop. The iterator:

• Filters out ignored files immediately (not yielded)
• Yields ignored directories for tracking but prevents descent via hasChildren()
• Uses caching to avoid duplicate isPathIgnored() checks
• Correctly handles complex gitignore patterns with negations

Performance Impact:

• Before: Foreach loop iterated 200+ times for 200 ignored files
• After: Foreach loop iterates ~5 times (only non-ignored items)
• Execution time: <0.01s for 200 ignored files

Changes:

• Refactored Distignore_Filter_Iterator with smart filtering in accept() method
• Updated get_file_list() to leverage iterator's filtering (reduced logic)
• New Behat performance test scenario
• Comprehensive PHPUnit test suite with 9 tests covering all filter iterator functionality
• Total: 250+ lines added/modified across 4 files

Test Coverage:

• 27 Behat scenarios passing (integration tests)
• 9 PHPUnit tests with 24 assertions passing (unit tests for Distignore_Filter_Iterator)
  • File filtering behavior
  • Directory tracking and descent prevention
  • Caching functionality
  • Negation patterns
  • Error handling
  • Nested directory handling
  • State sharing across child iterators

Compatibility: All 27 existing Behat test scenarios pass, plus new performance test added. All 9 PHPUnit tests pass.

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Performance Issue: RecursiveIteratorIterator scans all files in ignored directories before filtering</issue_title>
<issue_description>I'll create the issue following the repository's template format:

---

Bug Report

• Yes, I reviewed the contribution guidelines.
• Yes, more specifically, I reviewed the guidelines on how to write clear bug reports.

Describe the current, buggy behavior

The get_file_list() method in src/Dist_Archive_Command. php (lines 493-536) uses RecursiveIteratorIterator which iterates through every single file in the directory tree, including all files inside directories that should be ignored according to .distignore. This causes severe performance degradation when dealing with large ignored directories like node_modules.

The problem occurs because:

1. The RecursiveIteratorIterator descends into every subdirectory, including ignored ones like node_modules/
2. For each file (potentially 30,000+ files in node_modules), the iterator:
   • Creates an SplFileInfo object
   • Enters the foreach loop
   • Calculates the relative filepath
   • Calls $this->checker->isPathIgnored() to check if it should be excluded
3. Only after all this work does it decide not to include the file in the archive

The check if ( $this->checker->isPathIgnored( $relative_filepath ) ) happens inside the loop for every single item found, rather than preventing descent into ignored directories in the first place.

Describe how other contributors can replicate this bug

1. Create a WordPress plugin with a node_modules directory containing 30,000+ files (or any large directory)
2. Add node_modules to your .distignore file:

node_modules
. git
vendor
tests

3. Run wp dist-archive . build. zip from the plugin directory
4. Observe that the command takes several minutes to complete
5. The command iterates through all 30,000+ files in node_modules even though the entire directory is ignored

Describe what you would expect as the correct outcome

The iterator should skip descending into directories that are marked as ignored in .distignore, avoiding the need to iterate through their contents entirely.

For a project with node_modules containing 30,000 files:

• Current behavior: 30,000+ iterations and isPathIgnored() checks, taking several minutes
• Expected behavior: Skip the node_modules directory at the directory level, only iterate through files that need to be processed, completing in seconds

Let us know what environment you are running this on

OS: [Various - affects all operating systems]
PHP version: [Various - affects all PHP versions]
WP-CLI version: [Various - affects current versions using this package]

The issue is present in the current implementation regardless of environment.

Provide a possible solution

The solution is to use a RecursiveFilterIterator to filter out ignored directories before the RecursiveIteratorIterator descends into them. This way, the iterator never enters ignored directories, avoiding thousands of unnecessary iterations.

The filter would check at the directory level: "If this is a directory and it's ignored in .distignore, don't descend into it." This is fundamentally different from the current approach which checks every file after already finding it.

Provide additional context/Screenshots

This is a well-known performance pattern issue with RecursiveIteratorIterator. The iterator is designed to "flatten" the entire directory tree before filtering can occur.

Related discussion: The issue was previously mentioned in #81 (comment)

For WordPress plugins with modern build processes (npm packages, composer vendor directories, etc.), this performance issue makes the dist-archive command nearly unusable without manually deleting these directories first, which defeats the purpose of having a .distignore file.

---

To submit this issue:

Go to https://github.com/wp-cli/dist-archive-command/issues/new and paste the content above, or would you like me to attempt to create it directly for you? </issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Performance Issue: RecursiveIteratorIterator scans all files in ignored directories before filtering #115

---

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.

[codecov]

Codecov Report

❌ Patch coverage is 91.02564% with 7 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
src/Distignore_Filter_Iterator.php	89.83%	6 Missing ⚠️
src/Dist_Archive_Command.php	94.73%	1 Missing ⚠️

📢 Thoughts on this report? Let us know!