how do I rename a Ruby method across an entire repo safely

Start with the lsp tool's findReferences operation for the authoritative callsite list, then grep for the old name to catch strings, comments, docs, and config. Apply the renames with Atlas's edit tool using replaceAll only where the match is unambiguous per file.

why is find and replace dangerous for renaming in Ruby

Ruby's dynamic dispatch means a method name is also a symbol, a string in a send call, a serialized job payload, and a YAML key, while unrelated classes may define the same method. A global replace corrupts files that never referenced your class.

what does Found multiple matches for oldString mean in Atlas

Atlas's edit tool enforces uniqueness on a single replacement and throws Found multiple matches for oldString when the target appears more than once in the Ruby file. You either add surrounding context to disambiguate or explicitly opt into replaceAll.

how do I find Ruby references that grep misses

Run the lsp tool's findReferences operation, which asks the language server for the true reference set including callers that grep would wrongly match or miss entirely. Atlas uses both tools, because each covers what the other cannot.

how do I know a Ruby rename is complete

Atlas runs RSpec through bash and then greps once more for the old name to prove zero remaining hits. RSpec alone is not enough, because a stale constant name in config/locales/en.yml or a Rakefile task has no spec covering it.

does Atlas work with Bundler and RSpec projects

Yes. The documented Ruby setup is to run atlas in a project with a Gemfile, let Atlas read your modules, gems, and Rakefile tasks, and have Atlas write RSpec examples or extract a module, then review the diff. RuboCop is the formatter.

will renaming a Ruby class break my queued background jobs

It can, which is why Atlas greps for the old name across strings and config, not just Ruby source. A job enqueued before the deploy carries the old class name as a serialized string, and only a text sweep finds it.

Rename a Symbol Across a Ruby Repo with Atlas (2026)

To rename a symbol across a Ruby repo with Atlas, you start with the lsp tool's findReferences operation, which returns the authoritative callsite list from the language server, then grep for the old name to catch the strings, comments, and config that the type system never sees. Atlas applies the mechanical renames with edit using replaceAll where the match is unambiguous, and edit refuses ambiguous single replacements by throwing Found multiple matches for oldString, so an unintended match in your Ruby source is an error rather than a silent corruption. RSpec then proves it, and a final grep proves zero remaining hits.

Why is find and replace dangerous for renaming a Ruby method?

A Ruby rename is where naive find-and-replace does the most damage, because Ruby's dynamic dispatch means a method name is also a string, a symbol, a hash key, and a metaprogrammed send target. A blind global replace of process across a Rails app in 2026 will corrupt files that never referenced your class.

Renaming in Ruby is genuinely harder than in a static language. The method calculate_total is a call site in app/services/order_pricer.rb, but the same characters also appear as a symbol in a define_method loop, as a string in a serialized job payload, and as a key in a YAML fixture. Meanwhile, three unrelated classes may define their own calculate_total that must not change. Atlas therefore does not run a global replace. Atlas uses the lsp tool's findReferences to get the true reference set from the language server, grep to catch strings and docs the compiler does not see, and edit with replaceAll only for the mechanical part where the match is unambiguous. Three tools, three different jobs, because a single fuzzy replace cannot distinguish any of these cases.

How does Atlas get the authoritative Ruby reference list?

Atlas runs the lsp tool's findReferences operation on the Ruby symbol as step 1 of the rename, getting the authoritative callsite list from the language server. For a constant such as Billing::TAX_RATE or a class such as OrderPricer, findReferences returns the real references across lib/, app/, and spec/, not every line that contains the string.

The language server is the only component that actually knows which OrderPricer you mean. Atlas runs the lsp tool's findReferences operation first, which returns the true reference set for the Ruby method, class, or constant across the project: the definition in app/services/order_pricer.rb, the callers in app/controllers, and the RSpec examples in spec/services/order_pricer_spec.rb. Atlas indexes code by AST declarations using tree-sitter, not blind line windows, so each Ruby method is retrieved as a declaration, and Atlas searches code with hybrid semantic and keyword retrieval fused by reciprocal rank fusion when the reference set needs widening by meaning. That list is the spine of the rename, and everything else is a correction to it.

How does grep catch the Ruby references the language server misses?

Atlas greps for the old Ruby name in step 2 of the rename, catching occurrences outside the type system: strings, comments, docs, and config. A method name that appears in a Sidekiq job payload, a key in config/locales/en.yml, or a string in a Rakefile task is invisible to findReferences but very much load-bearing.

Ruby's dynamism means the reference set the language server sees is a subset of the real one. Atlas therefore runs grep for the old name after findReferences, sweeping strings, comments, docs, and config. That catches the serialized class name in a queued background job, the method referenced by a string in a send call, the constant named in a YAML fixture under spec/fixtures, and the mention in a doc comment or README. Atlas's grep takes a real regex plus include and path filters, so scoping to *.rb and then widening to *.yml and *.md is a couple of calls. Skipping this step is how a Ruby rename passes RSpec locally and then explodes in production when a job enqueued before the deploy tries to instantiate a class that no longer exists.

How does Atlas's edit tool prevent an unintended Ruby rename?

Atlas applies mechanical Ruby renames with edit using replaceAll where the match is unambiguous per file. Where 1 occurrence must change, edit enforces uniqueness: it throws Found multiple matches for oldString unless you add context or opt into replaceAll, so an unintended match is an error in 2026, not a silent corruption.

The edit tool's uniqueness rule is the safety property that makes this workflow trustworthy. When Atlas needs to change one occurrence of a Ruby identifier in app/models/order.rb but that identifier appears three times, edit throws Found multiple matches for oldString rather than picking one. To proceed you either add surrounding context that makes the target unambiguous, or explicitly opt into replaceAll. Both are deliberate acts. Atlas computes a unified diff for every file edit and surfaces it for approval before writing, so each renamed Ruby file is reviewed as its own diff, and Atlas snapshots file changes as git patches so edits can be diffed and rolled back. Every Atlas tool call is permission-gated against allow, ask, and deny rules before it runs, including the Bundler and RSpec commands that follow.

How do I prove a Ruby rename is complete across the repo?

Atlas proves a Ruby rename is complete by running the RSpec suite through bash and then grepping once more for the old name to confirm 0 remaining hits. A green RSpec run alone does not prove completeness, because a stale name in config/locales/en.yml has no spec covering it.

Completeness is two claims, and Atlas checks both. First, behavior: Atlas compiles and tests with bash, running RSpec across spec/ so any callsite the rename broke fails loudly. Bundler manages the gems that suite depends on, so the run uses the same Gemfile.lock your CI does. Second, coverage: Atlas greps once more for the old name to prove zero remaining hits, which catches the YAML key, the doc comment, and the string in a Rakefile task that RSpec would never have exercised. RuboCop then formats the touched Ruby files so the diff a reviewer reads is the rename rather than style noise. Atlas reads git branches, status, and diffs, and can stage and create commits on your behalf, so the finished rename lands as one reviewable commit.

Step by step

01Run atlas in a project with a Gemfile so Atlas can read your modules, gems, and Rakefile tasks.
02Run the lsp tool's findReferences operation on the Ruby method, class, or constant to get the authoritative callsite list from the language server.
03Run grep for the old name to catch occurrences outside the type system: strings, comments, docs, and config such as config/locales/en.yml or a Sidekiq job payload.
04Record the green baseline by running RSpec through bash before renaming anything.
05Apply the mechanical renames with edit using replaceAll where the match is unambiguous per Ruby file.
06Where a single occurrence must change, add surrounding context: edit enforces uniqueness and throws Found multiple matches for oldString unless you opt into replaceAll.
07Review the unified diff Atlas surfaces for each renamed Ruby file before it writes.
08Compile and test with bash by running RSpec, using the gems Bundler resolved from your Gemfile.lock.
09Grep once more for the old name to prove zero remaining hits, then run RuboCop over the touched files and commit.

Frequently asked questions

how do I rename a Ruby method across an entire repo safely: Start with the lsp tool's findReferences operation for the authoritative callsite list, then grep for the old name to catch strings, comments, docs, and config. Apply the renames with Atlas's edit tool using replaceAll only where the match is unambiguous per file.
why is find and replace dangerous for renaming in Ruby: Ruby's dynamic dispatch means a method name is also a symbol, a string in a send call, a serialized job payload, and a YAML key, while unrelated classes may define the same method. A global replace corrupts files that never referenced your class.
what does Found multiple matches for oldString mean in Atlas: Atlas's edit tool enforces uniqueness on a single replacement and throws Found multiple matches for oldString when the target appears more than once in the Ruby file. You either add surrounding context to disambiguate or explicitly opt into replaceAll.
how do I find Ruby references that grep misses: Run the lsp tool's findReferences operation, which asks the language server for the true reference set including callers that grep would wrongly match or miss entirely. Atlas uses both tools, because each covers what the other cannot.
how do I know a Ruby rename is complete: Atlas runs RSpec through bash and then greps once more for the old name to prove zero remaining hits. RSpec alone is not enough, because a stale constant name in config/locales/en.yml or a Rakefile task has no spec covering it.
does Atlas work with Bundler and RSpec projects: Yes. The documented Ruby setup is to run atlas in a project with a Gemfile, let Atlas read your modules, gems, and Rakefile tasks, and have Atlas write RSpec examples or extract a module, then review the diff. RuboCop is the formatter.
will renaming a Ruby class break my queued background jobs: It can, which is why Atlas greps for the old name across strings and config, not just Ruby source. A job enqueued before the deploy carries the old class name as a serialized string, and only a text sweep finds it.
how do I undo a bad rename made by an AI agent in Ruby: Atlas snapshots file changes as git patches so edits can be diffed and rolled back, and it computes a unified diff for every file edit and surfaces it for approval before writing. You revert the file that broke RSpec and keep the rest.

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