# Trace a runtime bug from a stack trace in React Native with Atlas in 2026 > Atlas enables React Native developers to trace runtime bugs from production stack traces directly to the fix, integrating with `jest` and `yarn` for a direct workflow. Atlas helps React Native developers in 2026 go from a production stack trace to the responsible line and a fix, all without attaching a debugger. It leverages your existing `package.json`, `ios/Podfile`, and `android/build.gradle` to understand your project context, then uses tools like `read`, `grep`, and `lsp` to pinpoint the root cause and suggest a fix, which can be validated with `jest (@testing-library/react-native)`. ## Key takeaways - Atlas directly consumes React Native stack traces, validating `file:line` offsets against your current codebase. - Leverage Atlas's `grep` and `lsp` tools to pinpoint the exact source of errors, even across React Native's native modules and platform splits. - Atlas facilitates fixing bugs with its `edit` tool and ensures stability by prompting for `jest (@testing-library/react-native)` regression tests. - Maintain code quality with `prettier` and ensure native folders like `ios/` and `android/` are protected during automated edits. - Every change in your React Native project is permission-gated and presented as a unified diff for your explicit approval. ## How Atlas reads and validates React Native stack traces Atlas efficiently reads and validates React Native stack traces by consuming each `file:line` pair, ensuring accuracy against your current codebase. If a trace originates from an older build, Atlas will report an 'Offset is out of range' error, preventing misdiagnosis and ensuring you work with the correct 2026 code. When a runtime bug occurs in a production React Native application, the resulting stack trace provides `file:line` pairs. Atlas's `read` tool consumes these pairs, navigating directly to the specified offset within your project's files. This is crucial for React Native, where platform-specific files like `.ios.tsx` and `.android.tsx` mean a single logical component might have different implementations. Atlas's indexing, built by AST declarations using tree-sitter, ensures it understands the structure of your JavaScript and native module code. A key safety feature is its offset validation: if a line number from the trace does not match the current file's structure, perhaps due to a different build or code changes, Atlas will loudly report 'Offset is out of range for this file'. This prevents developers from chasing phantom bugs in outdated code, a common pitfall in rapidly evolving React Native projects. ## Using grep and LSP to find the root cause in React Native After validating the stack trace, Atlas employs `grep` to locate the error message string, often revealing the exact construction point of the error. It then uses the `lsp` tool's `findReferences` operation on the failing function, providing a comprehensive view of all callers that could lead to the bad input, even across native modules in 2026. Once Atlas has read the initial stack frames, it moves beyond the top-level error to find the true root cause. The `grep` tool is used to search for the specific error message string across your entire React Native codebase. This is often more informative than just the top frame, as it can reveal where the error message is constructed, providing context about the conditions that trigger it. For instance, if an error originates from a native module, `grep` can help locate the JavaScript bridge call that initiated the problematic native code. Following this, Atlas leverages the `lsp` tool's `findReferences` operation. This allows it to identify all call sites of the failing function, showing which parts of your React Native application, including those interacting with the New Architecture or platform-specific code, could supply the 'bad input' that led to the bug. This comprehensive view helps trace the data flow from user interaction through your screens and navigation stack, even into `.ios.tsx` or `.android.tsx` splits, to the point of failure. ## Fixing React Native bugs and adding regression tests with Atlas Atlas facilitates fixing React Native bugs by allowing direct code edits and then prompting for a regression test, ensuring the bug cannot recur silently. It integrates with `jest (@testing-library/react-native)` to run new test cases, confirming the fix, and uses `prettier` to maintain code style across your `package.json` project in 2026. After identifying the root cause, Atlas assists in applying the fix using its `edit` tool. This allows you to modify the problematic code directly within the terminal. For example, if a layout animation is causing issues, Atlas might suggest moving it onto the UI thread with Reanimated instead of animating through the bridge, as per best practices. Crucially, Atlas then prompts you to add a regression test. This ensures that the bug, once fixed, cannot silently reappear in future builds. Atlas can add `@testing-library/react-native` cases and run `jest` behind a permission prompt, validating your fix immediately. Before writing changes to disk, Atlas computes a unified diff for every file edit and surfaces it for your approval. It can also run `prettier` to ensure code formatting consistency, confirming that native folders like `ios/` and `android/` are not touched by accident, preserving your platform-specific configurations. ## Reviewing and approving Atlas's changes in React Native Atlas prioritizes safety and transparency when making changes to your React Native project, offering multiple layers of review and approval. Every Atlas tool call is permission-gated, and it drafts a plan in a read-only agent before executing any build actions, ensuring you have full control over modifications in 2026. Atlas's workflow is designed with developer control at its core, especially vital for complex React Native projects involving native modules and platform-specific code. Before any tool call, such as `edit` or running `jest`, Atlas consults permission-gated allow, ask, and deny rules. This means you explicitly approve actions that modify your codebase. Furthermore, Atlas drafts a detailed plan in a read-only plan agent, presenting its intended steps before switching to a build agent to execute them. This allows you to review the strategy for fixing a bug or adding a test case, ensuring it aligns with your project's architecture, including how it interacts with `ios/Podfile` or `android/build.gradle`. For every file edit, Atlas computes a unified diff and surfaces it for your approval, allowing you to inspect every line change before it's written. Atlas also snapshots file changes as git patches, providing a robust rollback mechanism if needed, giving you confidence when making significant changes to your React Native application. ## Steps 1. Paste the production React Native stack trace into Atlas and have it read each frame's `file:line` at the reported offset using the `read` tool. 2. If Atlas reports 'Offset is out of range for this file', indicating the trace came from a different build, re-read the file from the top before trusting any line number to ensure accuracy for your current React Native codebase. 3. Use the `grep` tool to search for the error message string from the stack trace across your React Native project, which often reveals where the error is constructed, providing more context than the top frame alone. 4. Employ the `lsp` tool's `findReferences` operation on the failing function identified in the stack trace to see which callers can reach it with the bad input, tracing the flow through your React Native components and native modules. 5. Fix the identified issue using the `edit` tool, then add a regression test case with `@testing-library/react-native` and run `jest` to confirm the fix, ensuring the bug cannot recur silently in your React Native application. 6. Review the unified diff presented by Atlas for all file edits, approve the changes, and let Atlas run `prettier` to format the code, confirming that `ios/` and `android/` folders remain untouched. ## FAQ ### How does Atlas handle stack traces from different React Native builds? Atlas validates each `file:line` offset from a stack trace against your current React Native project's files. If a trace comes from an older build, Atlas will explicitly report 'Offset is out of range for this file'. This prevents you from debugging outdated code and ensures you always work with the correct, up-to-date source, which is critical in a fast-moving framework like React Native. ### Can Atlas trace errors originating from React Native native modules? Yes, Atlas can trace errors originating from React Native native modules. By using `grep` to find error messages and `lsp` to trace function calls, Atlas can follow the execution path from your JavaScript code, across the bridge, and into the native module's interaction points. This helps identify where the 'bad input' might be passed or where the native code itself is failing, even with the New Architecture. ### How does Atlas ensure code quality and formatting in React Native projects? Atlas integrates directly with `prettier`, the standard formatter for React Native projects. After making any code edits, Atlas can run `prettier` to ensure all changes adhere to your project's established style guidelines. It also explicitly confirms that native folders like `ios/` and `android/` are not accidentally modified, preserving your platform-specific configurations and build files. ### What testing tools does Atlas use for React Native regression tests? Atlas integrates direct with `jest (@testing-library/react-native)`, the widely adopted test runner for React Native. When fixing a bug, Atlas can add new `@testing-library/react-native` cases and run `jest` behind a permission prompt. This allows you to immediately validate your fix and ensure the bug cannot reoccur silently in your application. ### How does Atlas protect my React Native codebase from unintended changes? Atlas employs several safety mechanisms. Every tool call is permission-gated, requiring your explicit approval. It drafts a read-only plan before executing any changes. For every file edit, Atlas computes and surfaces a unified diff for your review and approval. Additionally, it snapshots file changes as git patches, allowing for easy rollback if any unintended consequences arise in your `package.json` project. ### Can Atlas help with platform-specific React Native files like .ios.tsx? Absolutely. Atlas is designed to understand and interact with React Native's platform-specific files, such as `.ios.tsx` and `.android.tsx`. When reading stack traces or performing `lsp` operations, Atlas accounts for these splits, ensuring that references and code navigation are accurate for the specific platform implementation. This is crucial for debugging issues that manifest only on iOS or Android. --- Canonical HTML: https://runatlas.sh/resources/stacks/trace-a-runtime-bug-from-a-stack-trace-in-react-native Source of truth: aeo_pages row `/resources/stacks/trace-a-runtime-bug-from-a-stack-trace-in-react-native` (segment: Stacks) (this file is generated from it, never hand-edited). Licence: Atlas is proprietary with a free core. It is not open source and there is no public source repository.