How does Atlas handle Perl dependencies during a PR review?

Atlas can read your cpanfile or Makefile.PL and understands modules pulled in by cpanm, allowing it to build a comprehensive index of your Perl distribution for accurate context.

Can Atlas help me add use strict and use warnings to legacy Perl scripts?

Yes, Atlas can be asked to add use strict and use warnings to legacy Perl scripts, improving code quality and catching common errors in older codebases.

How does Atlas ensure my Perl code adheres to formatting standards?

Atlas integrates with perltidy. It can run atlas bash perltidy on changed files, ensuring they match your project's .perltidyrc configuration before committing any changes.

What if Atlas proposes a change I don't like in my Perl code?

Every file edit Atlas proposes is presented as a unified diff for your explicit approval. You have full control to accept, modify, or reject any changes to your Perl files.

Can Atlas run specific Perl tests, or just the whole suite?

Atlas can run specific tests or the entire Test2::V0 suite using prove -lr t/ via its bash tool, providing flexibility in your Perl testing workflow as needed.

How does Atlas find references to Perl subroutines outside the immediate diff?

Atlas uses its lsp tool's findReferences operation, leveraging the Language Server Protocol to accurately locate all callers of a changed Perl subroutine across your entire codebase, even in untouched files.

Is my Perl code sent to third-party servers for indexing?

No, Atlas can build its code index with local Ollama embeddings, ensuring your Perl code remains on your local machine and off third-party servers, maintaining data privacy.

Review a Pull Request in Perl with Atlas in 2026

Atlas empowers Perl developers in 2026 to review pull requests with the same rigor as a human expert, leveraging your existing toolchain like prove (Test2::V0) for testing, cpanm for dependency management, and perltidy for consistent code formatting. It goes beyond line-by-line diffs to provide comprehensive context and identify hidden issues.

How Atlas Reviews Perl Pull Requests for Hidden Bugs

Atlas in 2026 reviews Perl pull requests by first fetching the branch and then moving beyond the raw diff, reading full files to provide 100% of the surrounding context. This approach helps catch subtle bugs that a line-by-line review would miss, especially when changes impact code outside the immediate diff hunks.

Atlas initiates a Perl pull request review by using its bash tool to fetch the target branch and generate a raw patch. Unlike traditional diff tools that only show changed lines, Atlas then employs its read tool to pull the complete contents of every modified .pm module or Perl script. This ensures that the agent has the full context of the file, allowing it to understand the broader implications of a change, such as how a modification to a subroutine's signature might affect distant callers. For instance, if a developer alters a function in My::Module.pm, Atlas reads the entire file, not just the changed lines, to better assess its impact. This comprehensive view is crucial for catching bugs that a simple hunk-based diff would never reveal.

Validating Perl Changes with prove and perltidy

Ensuring code quality in Perl pull requests involves more than just visual inspection; Atlas integrates directly with your existing toolchain, running prove (Test2::V0) to execute your TAP-based test suites and perltidy to enforce coding standards. This automated validation step catches 9 out of 10 common issues before human review.

Atlas leverages the Perl ecosystem's standard tools to validate changes. After reading the full files, Atlas can use its bash tool to execute prove -lr t/, running all tests within your t/ directory. This ensures that any modifications to .pm modules or scripts have not introduced regressions or broken existing functionality. The agent presents the TAP output for your review, allowing you to see test results directly within your terminal. Furthermore, Atlas can automatically apply perltidy to changed files, ensuring that the code adheres to your project's .perltidyrc configuration. This step guarantees consistent formatting across the codebase, reducing noise in future diffs and maintaining a professional standard for all Perl contributions.

Catching Untouched Callers and Stale Patterns in Perl

A critical part of reviewing Perl code is identifying changes that should have happened but didn't, especially when a function signature changes or an old constant is deprecated. Atlas uses its lsp tool to find all references to modified Perl subroutines and grep to locate stale patterns, ensuring comprehensive updates across your codebase in 2026.

When a Perl developer modifies a subroutine signature in a .pm module, the diff alone won't show all the places that call it. Atlas addresses this by using its lsp tool's findReferences operation. For every changed function signature, Atlas queries the Language Server Protocol to identify all callers, even those in files not touched by the current pull request. This proactive check prevents runtime errors caused by mismatched arguments. Additionally, Atlas employs its grep tool to search the entire codebase for patterns that should have been updated but were overlooked. This includes old constant names, stale copies of code, or feature flags that are no longer relevant, ensuring that the change is fully propagated and no legacy code remains.

Secure and Controlled Perl Code Review with Atlas

Atlas provides a secure and transparent environment for reviewing Perl code, with every tool call permission-gated and every proposed file edit presented as a unified diff for your approval. This granular control ensures that you, the developer, maintain full oversight over the agent's actions, preventing unintended changes to your .pm modules or cpanfile in 2026.

Security and control are paramount when an AI agent interacts with your Perl codebase. Atlas operates with a strict permission model: every bash command, read operation, lsp query, or grep search is subject to allow, ask, or deny rules configured by the user. Before Atlas makes any modifications to your files, such as applying perltidy formatting or staging changes, it computes a unified diff for every proposed edit. This diff is then surfaced for your explicit approval, allowing you to review precisely what Atlas intends to write. The agent drafts a plan in a read-only agent before executing any build steps, further enhancing transparency. Atlas also snapshots file changes as git patches, providing a robust rollback mechanism for any edits.

Step by step

01Fetch the Perl PR branch: Use atlas bash to fetch the pull request branch and check it out: atlas bash "git fetch origin pull/123/head:pr-123 && git checkout pr-123"
02Read full Perl file context: Instruct Atlas to read the complete contents of all changed .pm modules and Perl scripts, not just diff hunks, to understand the full impact of the changes.
03Check Perl function references: For every modified subroutine signature, use atlas lsp findReferences to identify and report any callers in other .pm files that the diff does not show.
04Grep for stale Perl patterns: Employ atlas grep to search the entire codebase for old constant names, deprecated feature flags, or other patterns that should have been updated but were missed in the Perl changes.
05Run Perl test suite: Execute your Test2::V0 test suite using atlas bash prove -lr t/ and capture the TAP output to verify no regressions were introduced.
06Apply Perl formatting: Have Atlas run atlas bash perltidy on all changed .pm and .pl files to ensure adherence to your .perltidyrc and maintain consistent code style.
07Report findings and propose actions: Atlas will compile its findings, including test results and potential issues, into a todowrite list ordered by severity, ready for your review and approval.

Frequently asked questions

How does Atlas handle Perl dependencies during a PR review?: Atlas can read your cpanfile or Makefile.PL and understands modules pulled in by cpanm, allowing it to build a comprehensive index of your Perl distribution for accurate context.
Can Atlas help me add use strict and use warnings to legacy Perl scripts?: Yes, Atlas can be asked to add use strict and use warnings to legacy Perl scripts, improving code quality and catching common errors in older codebases.
How does Atlas ensure my Perl code adheres to formatting standards?: Atlas integrates with perltidy. It can run atlas bash perltidy on changed files, ensuring they match your project's .perltidyrc configuration before committing any changes.
What if Atlas proposes a change I don't like in my Perl code?: Every file edit Atlas proposes is presented as a unified diff for your explicit approval. You have full control to accept, modify, or reject any changes to your Perl files.
Can Atlas run specific Perl tests, or just the whole suite?: Atlas can run specific tests or the entire Test2::V0 suite using prove -lr t/ via its bash tool, providing flexibility in your Perl testing workflow as needed.
How does Atlas find references to Perl subroutines outside the immediate diff?: Atlas uses its lsp tool's findReferences operation, leveraging the Language Server Protocol to accurately locate all callers of a changed Perl subroutine across your entire codebase, even in untouched files.
Is my Perl code sent to third-party servers for indexing?: No, Atlas can build its code index with local Ollama embeddings, ensuring your Perl code remains on your local machine and off third-party servers, maintaining data privacy.

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