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How to Build a Resilient Codebase Using Cursor's AI Agent for Automated Debugging

Give Cursor reliable feedback loops before asking it to repair code: establish types, linting, formatting, and focused tests, let the agent reproduce a failure, then inspect the diff and rerun the same checks plus a reusable branch review.

How to Build a Resilient Codebase Using Cursor's AI Agent for Automated Debugging

Lee explains how types, linting, formatting, and tests give Cursor feedback it can act on, demonstrates an agent fixing lint errors and rerunning the command, and shows a reusable branch-review command.

Before you start

What you need

  • A version-controlled codebase with a clean baseline
  • Documented typecheck, lint, format-check, test, and build commands
  • A reproducible failing command or test
  • A narrow task boundary and files that must not change
  • A branch or commit that makes the proposed diff easy to inspect

What you’ll make

A small, explained code change that fixes the reproduced failure, passes the relevant checks, and survives a branch-level review for behavior the narrow command may miss.

Tools used

Step by step

The workflow

Follow the sequence once, then adapt the prompts, checks, and handoffs to your own setup.

3 steps

Step01

Establish Your Code Guardrails

Start from a clean commit and make the project feedback explicit: strict types where supported, a linter, deterministic formatting checks, focused tests, and documented commands that both humans and agents can run.

Step02

Prompt the Agent to Automatically Fix Errors

Give Cursor the failing command and a narrow repair boundary. Require it to reproduce the issue, explain the cause, show the planned files, make the smallest fix, and rerun the checks.

Example prompt
Run [failing command] and reproduce the issue. Explain the root cause and list the files you expect to change. Make the smallest fix within [scope]. Do not disable rules, weaken types, delete tests, or change unrelated behavior. Rerun [focused checks] and summarize the diff.
Step03

Create Custom Commands for Code Reviews

Create a reusable review command for the branch diff. Check loading and offline states, error handling, security-sensitive code, data changes, test coverage, and accidental scope, then inspect each finding before making another edit.

Example prompt
Review the current branch diff against [base]. Look for correctness regressions, unsafe type or lint suppressions, missing error and loading states, offline or retry issues, security and privacy risks, data migration concerns, and missing tests. Cite files and lines. Do not modify code until I select a finding.

Treat every review finding as a hypothesis. Confirm it in the referenced code or with a focused test before changing the branch.

What good looks like

  • The agent reproduces the failure before editing and identifies the exact command and evidence.
  • The diff addresses the cause without weakening types, rules, tests, or error handling.
  • Focused checks and the broader required suite pass from a clean state.
  • The reviewer can explain the change, its risk, and how to revert it.

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After the steps

Runbook notes

How to recover when the loop fails and where human judgment helps.

Recover

If it goes sideways

The agent makes the warning disappear by disabling a lint rule, widening a type, or deleting a test
Forbid guardrail changes unless the task explicitly requires them and inspect configuration, suppressions, type assertions, and deleted coverage.
An automatic repair changes unrelated files or behavior
Set a file and behavior boundary, review the diff before acceptance, and revert unrelated edits.
The named check passes but the application or a neighboring path is broken
Run the appropriate typecheck, test, build, and targeted behavior checks, not only the command that first failed.
A background agent edits code that overlaps active work
Use separate branches or worktrees, assign non-overlapping scope, and reconcile diffs before combining them.

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